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The Varroa destructor mite is a parasitic threat to managed and feral honey bee colonies around the world. Beekeepers use miticides to eliminate Varroa in commercial hives, but these chemicals can diminish bee health and increase miticide resistance. In contrast, feral honey bees have developed multiple ways to counteract mites without chemical treatment. We compared mite levels, grooming habits, and mite-biting behavior between feral Africanized honey bees (genomically verified Apis mellifera scutellata hybrids) and managed Italian honey bees (A. mellifera ligustica). Surprisingly, there was no difference in mite infestation levels between scutellata-hybrids and managed bees over one year despite the regular use of miticides in managed colonies. We also found no differences in the social immunity responses of the two groups, as measured by their hygienic habits (through worker brood pin-kill assays), self-grooming, and mite-biting behavior. However, we provide the first report that both scutellata-hybrids and managed honey bees bite off mite chemosensory forelegs, which the mites use to locate brood cells for reproduction, to a significantly greater degree than other legs (a twofold greater reduction in foreleg length relative to the most anterior legs). Such biting may impair mite reproduction.

Six Corsican essential oils (EOs) from Humulus lupulus were studied for their activity against Varroa destructor adults and Apis mellifera pupae. The GC/MS analysis of EOs showed that the major compounds of all accessions were α-Humulene, Myrcene, α-Selinene, β-Selinene, (E)-β-Farnesene, and (E)-β-Caryophyllene. Bioassays showed that EOs from each accession acted as toxins and repellents against V. destructor adults, with lower toxicity towards A. mellifera pupae. In terms of efficacy against V. destructor adults, Smaragd 2020 oil displayed the highest performance, with LC50 and LC90 values of 2.33 and 7.83 µL/L air, respectively. Meanwhile, Smaragd 2019 and Tettnanger EOs showed moderate toxicity, with LC50 values of 3.101 and 3.66 µL/L air, along with LC90 values of 11.67 and 19.89µL/L air, respectively. The oils from Biguglia and Ajaccio were strongly repellent to Varroa adults. At the lowest concentration (2 µL/mL), these EOs exhibited percentage of repellence greater than 70% after 2h exposure, with RC50 values of 1.66 and 1.26 µL/L air, respectively. Concerning their insecticidal effects, EOs demonstrate reduced toxicity towards bee pupae when compared to Varroa mites. Notably, Ajaccio stands out for inducing lower mortality among bee pupae, with a selectivity ratio below 2 and LC50 of 11.25 µL/L air. [ABSTRACT FROM AUTHOR]

House mites frequently trigger allergic conditions. Although conventional treatments are effective, they can result in drug resistance and pose risks to the environment, human health, and non-target organisms. Therefore, this study evaluates new botanical extracts for their biological activities against Dermatophagoides pteronyssinus (Trouessart 1897; Pyroglyphidae), D. farinae (Hughes 1961; Pyroglyphidae), and Tyrophagus putrescentiae (Schrank 1781; Acaridae), not only to control them but also to reduce their allergens (dead bodies and faecal particles) by keeping them away. It is noteworthy that of these plants, Allium cepa L. (Alliaceae) and Solanum melongena L. (Solanaceae) peel extracts, as well as leaves of Hibiscus sabdariffa L. (Malvaceae), were tested for the first time in the present study as new bioacaricides, while Piper nigrum L. (Piperaceae) and H. sabdariffa leaves proved to be new botanical repellents for these mite species. Based on LC50 values, A. cepa, Beta vulgaris, and S. melongena extracts had the most potent toxic effects on these mite species, while extracts of Aloe vera, Capsicum annum, and P. nigrum had the strongest repellent activity against them at the highest concentration. These natural plant extracts may have valuable potential as new acaricidal products. [ABSTRACT FROM AUTHOR]

BACKGROUND: Owing to its systemic mode‐of‐action and ease of application, lithium chloride (LiCl) is an ideal varroacide for the control of Varroa destructor infestations in honey bee colonies. To better understand how LiCl functions within a colony, we screened different parts of honey bee anatomy for lithium accumulation. We wanted to elucidate the time‐dependent effects of LiCl on V. destructor and its metabolism within honey bees when they were fed continuous LiCl treatments, as well as evaluate potential adverse effects such as accumulation in the hypopharyngeal glands of nurse bees, which could negatively impact queens and larvae. RESULTS: Cage experiments reveal rapid acaricidal onset, with >95% mite mortality within 48 h of treatment. Bee hemolymph analysis supports these observations, showing a rapid increase in lithium concentration within 12 h of treatment, followed by stabilization at a constant level. Lithium accumulates in the rectum of caged bees (≤475.5 mg kg−1 after 7 days of feeding 50 mm LiCl), reflecting the bees' metabolic and excretion process. Despite concerns about potential accumulation in hypopharyngeal glands, low lithium levels of only 0.52 mg kg−1 suggest minimal risk to the queen and 1st‐ and 2nd‐instar larvae. Cessation of LiCl treatment results in a rapid decline in mite mortality in the first 5 days, which increases again thereafter, resulting in mite mortality of 77–90% after 10 days. CONCLUSION: These findings help optimize LiCl application in colonies to achieve high Varroa mortality without unwanted adverse effects and provide important baseline data for future registration. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The cattle tick Rhipicephalus (Boophilus) microplus (Canestrini, 1887) (Ixodida, Ixodidae) is responsible for significant economic losses in bovine production in tropical and subtropical regions worldwide. Control of this tick predominantly involves the use of chemical acaricides; however, their indiscriminate use has led to the selection of resistant populations. A survey on tick populations was conducted in the state of Rio Grande do Sul, in Brazil, to assess the prevalence of multiple resistance to acaricides in cattle farms. Additionally, questionnaires were administered to identify potential risk factors associated with multiple resistance to acaricides. In total, 176 farms with a bovine population of ≥40 cattle were randomly assigned for tick sampling. The resistance to six acaricidal compounds was investigated by bioassays. A larval packet test was performed for amitraz, chlorpyrifos, cypermethrin, fipronil and ivermectin. Fluazuron was screened using an adult immersion test. Multiple resistance to acaricides (i.e., resistance to three or more compounds) was detected in 173 samples, representing 98% of the total samples. Among these samples, 125 (71%) showed resistance to all six compounds tested. Additionally, we classified the resistance intensity into four levels (I to IV) based on the quartile distribution of the bioassay data. Ten samples (6%) showed high and very high levels (III and IV) of resistance to all six compounds tested. Three variables were significantly associated with multiple resistance to the six acaricides tested: (i) use of injectable acaricides to control ticks, (ii) application of more than five acaricide treatments per year, and (iii) farms with larger herds (≥232 animals). These results regarding widespread resistance and the emergence of multiple resistance to acaricides ticks are alarming and highlight the significant challenge of tick control in southern Brazil. [ABSTRACT FROM AUTHOR]

This study aims to determine the resistance ratios of Tetranychus urticae Koch red form (RF) and Tetranychus turkestani (Ugarov & Nikolskii) populations collected from cotton fields in Soke, Germencik, Kocarli and Nazilli districts of Aydin province to commonly used acaricides (abamectin, hexythiazox, etoxazole, spiromesifen). The potential role of detoxification enzymes (esterase, glutathione-s-transferase (GST), P450 monooxygenase (P450)) in acaricide resistance was also assessed. Overall populations of T. urticae RF presented varying ratios of resistance to these acaricides with all three populations (G15R21, K24R21, S3R21) showing significant resistance to abamectin (187.1–223.66 fold), hexythiazox (156.31–168.25 fold), etoxazole (409.58–517.20 fold) and spiromesifen (981.77–1246.11 fold). In contrast, all five T. turkestani populations (G4G21, K16G21, N1G21, N11G21, S19G21) were susceptible to abamectin, etoxazole, and spiromesifen, but exhibited some resistance to hexythiazox (164.34–182.39 fold). The resistance ratios of T. turkestani were however lower compared to T. urticae RF. A relationship was also found between detoxification enzymes and resistance. Esterase activity varied among mite populations, with the highest levels recorded in resistant populations of T. urticae (G15R21 and K24R219) with rates ranging between 6.48 and 7 mOD/min/mg protein. GST activity was highest in resistant mite populations (T. urticae S3R21 and T. turkestani K16G21). T. turkestani N11G21 population exhibited the highest P450 enzyme activity, reaching 4.39 RFU/30 min/mg protein. This study was the first to determine the resistance ratios of T. turkestani to hexythiazox in Türkiye, and on a global scale. [ABSTRACT FROM AUTHOR]

Two-spotted spider mite (Tetranychus urticae Koch, 1836, Acari: Tetranychidae) causes significant yield losses in cultivated plants, especially depending on the season. Chemical methods are the main methods of controlling this pest. However, besides the environmental, human, and animal health problems arising from chemical control, adverse effects such as resistance and residues limit the success and sustainability of chemical control. This experiment was conducted in the applied acarology laboratory of the Directorate of Plant Protection Central Research Institute in Ankara, Türkiye, in incubators maintained at 25 ± 1 °C temperature, 50–65% humidity, and 16 L: 8 D h photoperiod. In this study, the potential acaricidal effect of aqueous extracts of Morus rubra, Daphne odora, Ficus carica, Matricaria chamomilla, and Mentha pulegium collected from Ankara and Adana provinces on T. urticae was investigated. For this purpose, the leaves of the plants were dried and ground and 1%, 3%, 6%, and 12% concentrations (w/v) of the extracts obtained were tested in three different application periods (1–6 day). Dipping and spraying methods were used to determine mortality and toxicity. The highest effect was 94.4% at the end of the 6th day at a 12% concentration of M. pulegium in the dipping method. On the other hand, the lowest mortality effect was 18.2% at the same time and concentration of M. chamomilla. In lethal toxicity studies, the highest toxicity was obtained from F. carica with an LC50 value of 4756 mg L−1, and the lowest toxicity was obtained from D. odora with an LC50 value of 12,417 mg L−1. We believe that plant extracts provide a valid alternative in effectively controlling two-spotted spider mites, reducing the need for pesticide use and minimizing residues. [ABSTRACT FROM AUTHOR]

The encapsulation of essential oils (EOs) in nanostructured lipid carriers (NLCs) represents a modern and sustainable approach within the agrochemical industry. This research evaluated the colloidal properties and insecticidal activity of NLCs loaded with thyme essential oil (TEO-NLC) and rosemary essential oil (REO-NLC) against three common arthropod pests of ornamental flowers: Frankliniella occidentalis, Myzus persicae, and Tetranychus urticae. Gas chromatography–mass spectrometry (GC-MS) analysis identified the major chemical constituents of the EOs, with TEO exhibiting a thymol chemotype and REO exhibiting an α-pinene chemotype. NLCs were prepared using various homogenization techniques, with high shear homogenization (HSH) providing the optimal particle size, size distribution, and surface electrical charge. A factorial design was employed to evaluate the effects of EO concentration, surfactant concentration, and liquid lipid/solid lipid ratio on the physicochemical properties of the nanosuspensions. The final TEO-NLC formulation had a particle size of 347.8 nm, a polydispersity index of 0.182, a zeta potential of −33.8 mV, an encapsulation efficiency of 71.9%, and a loading capacity of 1.18%. The REO-NLC formulation had a particle size of 288.1 nm, a polydispersity index of 0.188, a zeta potential of −34 mV, an encapsulation efficiency of 80.6%, and a loading capacity of 1.40%. Evaluation of contact toxicity on leaf disks showed that TEO-NLC exhibited moderate insecticidal activity against the western flower thrips and mild acaricidal activity against the two-spotted spider mite, while REO-NLC demonstrated limited effects. These findings indicate that TEO-NLCs show potential as biopesticides for controlling specific pests of ornamental flowers, and further optimization of the administration dosage could significantly enhance their effectiveness. [ABSTRACT FROM AUTHOR]

The Rhipicephalus microplus tick causes enormous economic losses in livestock farming around the world. Despite several promising studies carried out with plant extracts such as Achyrocline satureioides against this ectoparasite, a major obstacle is related to pharmaceutical presentation forms. There is no study showing xantan gum-based hydrogel and polycaprolactone nanoparticles containing A. satureioides extract against R. microplus larvae. The objective of this study was to incorporate A. satureioides extract to develop a nanoformulation (AScn) and a hydrogel (ASlh) and evaluate them against R. microplus larvae with the purpose of increasing the contact time of the extract with the larvae and improve the effectiveness. The ethanolic extracts were incorporated in polycaprolactone nanoparticles and characterized via analysis of the mean hydrodinamic diameter and polidispersity index. The xanthan gum-based hydrogel formulation was prepared with crude extract of A. satureioides 40 mg/mL, 0.25% xanthan gum, and 8% poloxamer, to determine the bioadhesiveness of the formulation in bovine leather and the flow rate of the formulation in the animal. The results in larvae demonstrated that when evaluated in the form of a hydrogel (ASlh), mortality was higher, with 91.48% mortality at a concentration of 20 mg/mL presenting itself as an interesting alternative for controlling this ectoparasite. [ABSTRACT FROM AUTHOR]

Ticks pose a significant threat due to their ability to lay thousands of eggs, which can persist in the environment for extended periods. While the impact of various compounds on adult and larval ticks has been studied, research on their efficacy against tick eggs is limited. This study evaluated the ovicidal activity of commercial acaricides, disinfectants, and natural products against Rhipicephalus annulatus eggs using the egg hatch assay (EHA). Deltamethrin and cypermethrin caused a non-significant inhibition of hatching (IH%), even at concentrations higher than the recommended levels. By contrast, the acaricides chlorpyrifos, phoxim, and amitraz significantly inhibited hatching at all tested concentrations. Ivermectin also demonstrated significant IH% at various concentrations but did not fully inhibit the hatching process. Among the disinfectants tested, Virkon-S®, TH4, and Chlorox showed insignificant effects, whereas formalin achieved an IH% of only 34.1% at a high concentration of 200 mg/mL. Natural products, carvacrol and thymol, exhibited significant ovicidal activity, with a significant IH%. In a semi-field application, phoxim (0.5 mg/mL) and deltamethrin (0.05 mg/mL) were sprayed on tick eggs on pasture soil from a farm. The results indicated that phoxim-treated eggs had a 40% IH%, while deltamethrin-treated eggs showed only an 8.79% IH%. In conclusion, the acaricides amitraz, phoxim, and chlorpyrifos, as well as the natural products carvacrol and thymol, caused significant toxicity to R. annulatus eggs. [ABSTRACT FROM AUTHOR]

Tetranychus urticae (Acari: Tetranychidae) is a widespread and serious mite pest that infests tomato plants and causes economic losses worldwide. We investigated the acaricidal efficacy of two isolates of entomopathogenic fungi (EPF) Metarhizium robertsii (WG-7) and Beauveria bassiana (WG-12) alone and in combination with abamectin when applied topically to tomato leaf discs in the laboratory against T. urticae. We also evaluated the establishment and proliferation of T. urticae mite life stages on tomato plants in the greenhouse after application of each of the above treatments. The combination of abamectin with each EPF caused 100% mortality in T. urticae immatures after 2 days while each EPF or abamectin alone caused moderate mortality, not exceeding 74.2% 3 days post-exposure. Complete (100%) mortality of adults was observed after 5 days in leaf discs treated with M. robertsii plus abamectin whereas B. bassiana plus abamectin caused 100% mortality after 7 days. The mean number of eggs, emerged immatures, and adults were significantly reduced on both sides of the leaves (i.e., abaxial and adaxial sides) after using the combined application of M. robertsii or B. bassiana plus abamectin, compared to abamectin alone and controls. Our results reveal that the acaricidal efficacy of abamectin combined with either EPF was significantly better in managing the T. urticae life stages than either treatment alone under greenhouse conditions. [ABSTRACT FROM AUTHOR]

BACKGROUND: The citrus red mite, Panonychus citri is a serious pest of the citrus industry and has developed resistance to many acaricides. Broflanilide is a novel meta‐diamide insecticide that binds to a new site on the γ ‐aminobutyric acid receptor with high potency against pests. However, little information has been reported about its effect on the citrus red mite. RESULTS: Broflanilide exhibited higher toxicity to female adults and eggs of a laboratory strain of P. citri The median lethal concentration (LC50), 9.769 mg/L and 4.576 mg/L, respectively) than other commonly used acaricides and was also toxic to two P. citri field strains. Broflanilide treatment with LC10, LC20, and LC30 significantly decreased the fecundity and longevity of female adults of F0P. citri compared with the control. The duration of larva, protonymph, deutonymph and adult, and total life span in the F1 generation were significantly reduced after treatment of F0 with broflanilide. Population parameters, including the intrinsic rate of increase (r) and finite rate of increase (λ), were significantly increased, and the mean generation time (T) of F1 progeny was significantly reduced in the LC20 treatment. The predicted population size of F1 increased when parental female adults were treated with sublethal concentrations. CONCLUSION: Broflanilide had high acaricidal activity toward P. citri, and exposure to a sublethal concentration significantly inhibited the population growth of F0. The transgenerational hormesis effect is likely to cause population expansion of F1. More attention should be paid when broflanilide is applied to control P. citri in citrus orchards. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The present study aimed to analyze the cladistics and population structure analysis of Rhipicephalus microplus ticks infesting buffaloes in Haryana, India, as well as the assessment of the anti-tick efficacy of the ethanolic extracts of Cassia fistula (bark, pod pulp, and flowers) against R. microplus larvae. The molecular characterization and population structure analysis were performed by targeting the amplification of the partial mitochondrial cytochrome C oxidase subunit 1 (cox1) gene, whereas anti-tick efficacy was evaluated using a larval packet test. The sequences generated herein revealed a homology of 98.26–100% to the GenBank-archived R. microplus sequences. In population structure analysis, high haplotype (0.500 ± 0.265) and low nucleotide (0.002 ± 0.001) diversities were recorded for the sequences generated in this study. Significantly negative neutrality indices were recorded for the overall dataset. The extracts were found to significantly affect mortality rates in a dose-dependent manner, and the ethanolic extracts of the bark, pod pulp, and flowers of C. fistula exhibited median lethal concentration (LC50) values of 27.989, 40.457, and 49.43 mg/mL, respectively. The LC50 value recorded for the combination of the ethanolic extracts of the bark, flower, and pod pulp of C. fistula was 19.724 mg/mL, whereas the synthetic acaricide ivermectin had an LC50 value of 351.56 mg/mL. In conclusion, R. microplus populations infesting cattle and buffalo hosts in India exhibited negligible genetic differentiation and high gene flow between them. Additionally, the combination of all C. fistula extracts could serve as a potential substitute for the synthetic acaricide. [ABSTRACT FROM AUTHOR]

The two-spotted spider mite, Tetranychus urticae Koch (TSSM), is an important cosmopolitan pest of agricultural crops that is often managed in greenhouses by augmentation of predatory mites in combination with acaricides. Here we examined the transgenerational effects of low lethal concentrations of a widely-used acaricide, Oberon Speed® (a combination of spiromesifen and abamectin), on the life history traits and population growth of T. urticae and two of its predators, Phytoseiulus persimilis Athias-Henriot and Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae). The concentrations employed corresponded to the LC10, LC20 and LC30 values estimated for TSSM protonymphs 48 h post-exposure in a topical bioassay, which yielded an LC50 value of 207.2 ppm. Parental exposure of TSSM to all three low concentrations increased the total developmental time of progeny; both the LC20 and LC30 treatments reduced adult longevity and number of oviposition days, but only the LC30 treatment increased the preoviposition period. Similarly, both the LC20 and LC30 treatments significantly reduced life table parameters (r, R0, λ, and GRR), and increased generation time (T) and population doubling time (DT). Although maternal exposure to the acaricide had various impacts on progeny life history, A. swirskii was less affected than P. persimilis, suggesting the former species would be more compatible for integration with Oberon Speed® for control of T. urticae in greenhouse vegetable production. [ABSTRACT FROM AUTHOR]

Background: Brown dog ticks (Rhipicephalus sanguineus sensu lato) are vectors of pathogens adversely affecting the health of dogs in many regions of the world. The three-host life cycle of R. sanguineus s.l., with all stages feeding on dogs, can lead to an uncontrolled build-up of large tick populations if not controlled by acaricides. However, frequent tick control on dogs using acaricides has led to the emergence of resistance to permethrin and fipronil. Currently, the larval packet test (LPT) is the standard tick resistance test, which is laborious, requires laboratory facilities, and takes at least 6 weeks before larvae derived from engorged female ticks can be tested. Our novel approach is to expose semi-engorged adult ticks to acaricides immediately after removing them from dogs, obtaining results within 24 h. Methods: Adult ticks from three laboratory colonies of R. sanguineus s.l. were tested in RaTexT®, a rapid tick exposure test in which ticks were confined to small compartments and exposed to an acaricide-impregnated, specially designed matrix. Resistance was confirmed by testing larvae derived from the same laboratory colonies using the LPT. RaTexT® was also used to determine the susceptibility of R. sanguineus acaricides in dog shelters. Results: RaTexT® detected resistance to permethrin in adult R. sanguineus s.l. ticks from two Brazilian laboratory colonies compared to a susceptible laboratory strain originating in Greece. Resistance was confirmed by LPT testing of larvae from the same colonies with resistance factors between 2.2 and 3.1. All laboratory strains were susceptible to fipronil. A suspected case of fipronil resistance at a dog shelter in Caxias do Sul, Brazil, was resolved within 24 h by testing adult ticks in RaTexT® and could be attributed to improper treatment. Conclusions: RaTexT® is a valuable tool for monitoring the development of resistance to synthetic pyrethroids or phenylpyrazoles in tick-infested dogs. [ABSTRACT FROM AUTHOR]

Seven acaricides were selected in the toxicity test on Tetranychus urticaris that break out on Clematis L.. Slide impregnation, leaf disk and toxicity test on pot were applied respectively for eggs, female adults and single population on plant in toxicity test. Results indicated that the order of curative effect from good to bad was matrine, abamectin+pyridaben, buflomedin, bifenazate+etoxazole, abamectin+etoxazole, spirodiclofen and bifenazate. Toxicity test on pot showed that the LC50 value were higher than that in slide impregnation and leaf disk test. Morever, the LC50 values that we obtained in this study were higher than previously reported LC50 values of T. urticaris that live on other plants which indicated that T. urticaria colonized on Clematis L. had higher tolerance to pesticides. This study would be helpful in providing theoretical basis for T. urticaria chemical control. [ABSTRACT FROM AUTHOR]

Bacillus thuringiensis (B. thuringiensis) is considered one of the most important entomopathogenic microorganisms. It produces potent toxins against insects. Therefore, the present study investigates the bioacaricidal properties of B. thuringiensis on the Hyalomma tick species. Firstly, we identify Hyalomma ticks based on morphological screening and molecular characterization. The cytochrome C oxidase subunit I (COX1) gene was selected for the polymerase chain reaction (PCR) analysis, which resulted in the amplification of 656 bp. The amplified products were sequenced, and the isolated (COX1) gene of ticks was submitted to the gene bank of NCBI (Accession No. OR077934.1). The nucleotide sequences were retrieved from the NCBI data bank by BLASTn analysis, which confirmed that all obtained sequences belong to genus Hyalomma, and multiple alignments confirmed that the sequence of Hyalomma anatolicum Tandojam‐isolate (HA‐TJ) 100% aligned with Hyalomma analoticum KP792577.1, Hyalomma detritum KP792595.1, Hyalomma excavatum KX911989.1, and H. excavatum OQ449693.1. The generated phylogenetic tree confirmed that sequences of HA‐TJ COX1 clustered with a single clad of H. analoticum, H. excavatum, and H. detritum. The acaricidal effect of B. thuringiensis toxins B. thuringiensis spore crystal mix (BtSCM) and B. thuringiensis crystal proteins (Btcps) was evaluated against larvae and adult life stages of Hyalomma ticks in vitro. We applied Btcps and BtSCM separately with different concentrations and calculated the mortality percentage. Adult mortality was estimated at the 8th, 10th, 12th, and 15th days posttreatment and larval mortality after 24 h. During treatment of the adult life stage, at first, ticks were immersed in different concentrations of Btcps and BtSCM for 5 min after the treatments, and the samples were transferred to sterile containers and placed in an incubator with 80% humidity at 23°C. Furthermore, Btcps produced the highest mortality on Day 15, 89 ± 1.00% at a concentration of 3000 μg/mL, followed by the 12th, 10th, and 8th days produced 83 ± 1.91%, 70 ± 1.15%, and 61 ± 1.00%, respectively. BtSCM produced mortality of 69 ± 1.91% on Day 15 at a concentration of 3000 μg/mL, followed by the 12th, 10th, and 8th days at 57 ± 2.51%, 37 ± 1.91%, and 34 ± 2.00%. The present study revealed that B. thuringiensis toxins produced a significant (p < 0.05) increase in mortality rate in adults of Hyalomma ticks. Additionally, Btcps and BtSCM were used to treat the larval stage. The treatments were applied to calculate the mortality percentage via the Laravel packet test. At a 1500 μg/mL concentration, Btcps resulted in the highest mortality of 98 ± 1.15%; this was followed by 1250 μg/mL, 1000 μg/mL, and 750 μg/mL, which produced mortalities of 76 ± 1.63%, 60 ± 1.63%, and 56 ± 1.63%, respectively. In addition, BtSCM produced a mortality rate of 79 ± 2.51% at a concentration of 1500 μg/mL. Furthermore, 75 ± 2.51%, 65 ± 1.91%, and 58 ± 1.15% mortality were observed at concentrations of 1250 μg/mL, 1000 μg/mL, and 750 μg/mL, respectively. The results showed a significant (p < 0.05) increase in larval mortality compared to the control group. We conclude that B. thuringiensis toxins are applicable as a bioacaricide. [ABSTRACT FROM AUTHOR]

This study was designed to evaluate the acaricidal effect and the mode of action of lemongrass essential oil (LEO) against Aleuroglyphus ovatus. Contact and fumigant mortality indicated that LEO had higher acaricidal activities at a low concentration, and the acaricidal action of LEO was significantly more effective by contact effects than by fumigant bioassay. Repellent rate against A. ovatus at different concentrations of LEO increased with application time. Observation on the toxic symptoms revealed that almost all mites were in immobilized type (IM type) in 30 min, but the symptom of knock-down type (KD type) appeared later. Cuticles of mites killed by LEO exhibited obvious colour change and deformation. Detoxification enzyme activity assay showed that glutathione S-transferase (GST) activity increased in mites treated by LEO compared to the controls. LEO increased catalase (CAT) activity of A. ovatus but inhibited superoxide dismutase (SOD) after 20 h. LEO also increased nitric oxide synthetase (NOS) and inhibited acetylcholine esterase (AChE) activities. Moreover, LEO acted as a fast-acting neurotoxin on A. ovatus. Our results suggest that LEO has an acaricidal potential and is a promising agent in control of A. ovatus. [ABSTRACT FROM AUTHOR]

Proprioseiopsis asetus and Amblyseius swirskii are excellent natural enemies of plant-feeding mites and small pests. In order to clarify the safety of the acaricide spirodiclofen to the predatory mites P. asetus and A. swirskii, here, we investigated the toxicity of the acaricide on the pest mite T. urticae (nymphs and adult females) and on both species of predatory mites, P. asetus and A. swiskii (eggs, nymphs, and female adults) by using the spray, slide-dip, and leaf residual toxicity methods, compared the selective toxicity and assessed the safety to these natural enemies. The results demonstrated that the corrected mortality in P. asetus and A. swirskii female adults was <5% at recommended spirodiclofen concentrations in the spray method. In the leaf residual toxicity method, P. asetus and A. swirskii egg-hatching rates did not differ significantly from the pure water control group. In the slide-dip method, spirodiclofen lethal concentration 50 (LC50) in P. asetus and A. swirskii female adults was noted to be 9,494.875 and 3,064.187 mg·L–1, respectively. In the spray method, spirodiclofen LC50 in P. asetus and A. swirskii nymphs was found to be 4,292.664 and 1,081.609 mg·L–1, respectively, and that in T. urticae female adults and nymphs was 55.189 and 40.862 mg·L–1, respectively. Spiroclofen selective toxicity ratios (STRs) in P. asetus female adults–T. urticae and P. asetus nymphs–T. urticae were 172.013 and 105.053, respectively, indicating that spiroclofen has a high positive selectivity toward the pest T. urticae and its natural enemy P. asetus. In contrast, spiroclofen STRs in A. swirskiis female adults–T. urticae and A. swirskiis nymphs–T. urticae were 55.522 and 26.470, respectively, indicating spiroclofen has a moderate positive selectivity toward the pest T. urticae and its natural enemy A. swirskii. In the safety evaluation, the spirodiclofen safety factor for P. asetus female adults and nymphs was 158.248–237.37 and 71.544–107.317, respectively, whereas that for A. swirskii female adults and nymphs was 50.070–76.605 and 18.027–27.040 respectively. All spirodiclofen safety factor values were much higher than 5, indicating that spirodiclofen is highly safe for P. asetus and A. swirskii; in particular, spirodiclofen is safer for P. asetus than for A. swirskii. [ABSTRACT FROM AUTHOR]

Citrus leprosis mite [Brevipalpus yothersi Baker (Acari: Tenuipalpidae)] is traditionally controlled with acaricide applications using a high volume of spray solution (> 2000 L.ha-1). However, high spray solution volumes can generate water waste and environmental contamination. An experiment was set up in a sweet orange orchard located in the municipality of Taquaral, São Paulo, Brazil, aiming to optimize the spray solution volume required for more efficient control of the leprosis mite. The experiment was conducted from December 2020 to July 2022. Two spray solution volumes were evaluated: 100 and 180 mL m–3 of plant canopy. In total, seven acaricide applications were performed. During the experiment, we assessed the incidence and infestation of the leprosis mite. Additionally, at the end of the experiment, we counted the number of plants and fallen fruits exhibiting leprosis symptoms. The treatment with a spray volume of 180 mL m–3 was more effective in controlling mites, as the incidence and infestation of B. yothersi were lower in this treatment. Moreover, this treatment resulted in fewer plants with fallen fruits and a reduced number of fallen fruits showing leprosis symptoms. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the acaricidal efficacy, tolerability of the target species, and residue levels of a thymolcontaining gelatin-based hydrogel developed as a controlled release system for varroosis control. The study was carried out on naturally infested honey bee colonies and results were compared with those of negative and positive control groups. The acaricidal efficacy of the negative control, positive control, and hydrogel treatment was 21.93 ± 2.87%, 81.09 ± 2.30%, and 70.32 ± 2.05%, respectively. For tolerability evaluations, the average number of dead bees per colony was determined to be 60.80 ± 8.01, 297.40 ± 21.4, and 86.80 ± 6.94 for the negative control, positive control, and hydrogel treatment, respectively. The average thymol residues in honey were measured as 0.030 ± 0.022 mg/kg, 5.498 ± 3.346 mg/kg, and 0.168 ± 0.110 mg/kg for the negative control, positive control, and hydrogel treatment, respectively. The average thymol concentrations in beeswax were 0.074 ± 0.047 mg/kg, 1.667 ± 0.855 mg/kg, and 0.476 ± 0.278 mg/kg for the negative control, positive control, and hydrogel treatment, respectively. The controlled release system developed in this study was found to prevent the transport of thymol out of the colony due to its structure, which is well tolerated by bees. Consequently, a single application can achieve longer infestation control. Furthermore, the lack of intervention by bees in the system ensures that bee mortality due to contact toxicity and residue levels in honey and beeswax are low. In addition to these advantages of the system, further development is required to increase the acaricide efficacy in order to make it an ideal alternative to existing varroacidal veterinary medicinal products. [ABSTRACT FROM AUTHOR]

Simple Summary: The mite Varroa destructor is the most damaging parasite of honey bees (Apis mellifera) worldwide. When necessary, mite control is mainly accomplished with acaricides. Optimal parasite control is achieved when the acaricide is applied during times of little or no brood in honey bee colonies, which varies by region. Therefore, in this study we analyzed the population dynamics of the mite in honey bee colonies established in a temperate semi-arid climate in Mexico by periodically sampling brood and adult bees, as well as by counting mites falling to the bottom board of hives over 10 months. We also measured brood and adult bee populations and food stores. It was found that the sampling period influences the population of V. destructor in the colonies. The mite population increased by 26% in the 10 months of sampling. It was observed that as the worker brood population increased, the mite infestation rate in adult bees decreased, and the opposite occurred when the amount of brood in the colonies was reduced. Monitoring V. destructor populations by recording fallen mites is more reliable than determining mite infestation rates in adult bees and brood. The best period to apply an acaricide treatment in the region of study is between November and December. This study aimed to analyze the population dynamics of the mite Varroa destructor in honey bee (Apis mellifera) colonies in a temperate semi-arid climate in Mexico. Ten colonies homogeneous in population, food stores, and levels of mite infestation were used. The mite infestation rate in brood and adult bees, total number of mites, daily mite fall, brood and adult bee population, and food stores were determined periodically for 10 months. There was a significant effect (p < 0.05) of sampling period on the population of V. destructor in adult bees, brood, total mite population, and daily fallen mites. The total mite population increased by 26% on average per colony. The increase in brood amount reduced the mite infestation rate in adult bees, and the opposite occurred when the brood decreased. Monitoring V. destructor populations by recording fallen mites is more reliable than determining mite infestation rates in bees, as mite fall has a dynamic pattern similar to that of the total mite population. The best period to apply an acaricide treatment in the region of study is between November and December because most mites were in the phoretic phase, since there was less brood in the colonies compared to other times. [ABSTRACT FROM AUTHOR]

Simple Summary: Pyridaben is an efficient, low-toxicity, broad-spectrum insecticide that impairs the predatory capabilities of predatory mites, but the specific mechanisms that affect the predatory functions remain underexplored. This study elucidated that pyridaben significantly diminished the predatory efficiency and searching behavior of the predatory mite Neoseiulus womersleyi. A gene linked to olfactive functions, NwNPC2a, was cloned from N. womersleyi. Post-treatment with pyridaben at LC30 and LC50 concentrations resulted in a substantial downregulation of NwNPC2a expression. Silencing NwNPC2a in N. womersleyi females led to significant reductions in predatory functions. The decrease in predatory performance at LC30 and LC50 concentrations was attributable to the suppression of NwNPC2a gene expression. Thus, the underlying molecular mechanism through which pyridaben compromises the predatory function of N. womersleyi likely involves the downregulation of NwNPC2a expression. Pyridaben is a widely utilized, broad-spectrum contact acaricide, which has notable sublethal effects that impair the predatory capabilities of predatory mites, but the specific mechanisms that affect the predatory functions remain underexplored. When predatory mites hunt for prey, they may rely on Niemann–Pick-type C2 (NPC2) proteins to collect herbivore-induced plant volatiles (HIPVs) and other odor molecules to locate and pursue their prey. This study elucidated that pyridaben significantly diminished the predatory efficiency and searching behavior of the predatory mite Neoseiulus womersleyi. Key metrics, including predatory capacity (a/Th) and predation rate (a) on various developmental stages of Tetranychus urticae, were markedly reduced in treated mites compared to controls. The searching efficiency (S) also declined proportionally with the increased sublethal dose of pyridaben. A gene linked to olfactive functions, NwNPC2a, was cloned from N. womersleyi. Post-treatment with pyridaben at LC30 and LC50 concentrations resulted in a substantial downregulation of NwNPC2a expression by 60.15% and 58.63%, respectively. Silencing NwNPC2a in N. womersleyi females led to significant reductions in the attack rate (a), handling time (Th), predation efficiency (a/Th), and maximum predation rate (1/Th). The searching efficiency (S) was also lower than that of the control group, displaying a slight decline with the increasing prey density. The findings revealed that pyridaben exerted inhibitory effects on both the predatory function and searching efficiency of N. womersleyi populations. The decrease in predatory performance at LC30 and LC50 concentrations was attributable to the suppression of NwNPC2a gene expression. RNA interference (RNAi) studies corroborated that the NwNPC2a gene plays a critical role in the predation process of N. womersleyi. Thus, the underlying molecular mechanism through which pyridaben compromises the predatory function of N. womersleyi likely involves the downregulation of NwNPC2a expression. [ABSTRACT FROM AUTHOR]

Development of acaricide resistance in tick population is a major concern in livestock as well as in pet animals. Reduced responsiveness has been observed against commonly used acaricides in Rhipicephalus sanguineus tick infested dogs in the Agartala city of North-eastern part of India. Two acaricides Deltamethrin and Fipronil were chosen for acaricidal resistance study using Adult Immersion Test (AIT) and Larval Packet Test (LPT). AIT study revealed the lowest and highest mortality of adult ticks at 25 ppm and 200 ppm concentration of Deltamethrin, respectively. Similarly for fipnonil, lowest and highest mortality was recorded at 25 ppm and 100 ppm, respectively. With increasing the concentration of both deltamethrin and fipronil, the reproductive index of ticks was found to be decreased with increased inhibition of oviposition. In LPT study, lowest mortality of R. sanguineus larvae was recorded at 25 ppm of deltamethrin and highest mortality at 200 ppm. For fipronil, lowest and highest mortality was recorded at 25 ppm and at 100 ppm, respectively. The study revealed that both the acaricides produced lower mortality of ticks at their market recommended doses. However, fipronil was found to be more effective than that of deltamethrin. The observed resistance warrants immediate measures to prevent further development of acaricide resistance in tick population in dogs in the study area. [ABSTRACT FROM AUTHOR]

The emergence of tick resistance against synthetic and eco-toxic chemical acaricides has stressed the need to find target-specific, non-toxic, and more potent alternatives such as botanicals. The current study was designed to investigate the acaricidal and repellent potential of ethyl acetate extract of Moringa oleifera seeds against Rhipicephalus microplus cattle ticks. Adult immersion test, larval immersion test, and tick climbing repellent assay were carried out to evaluate the acaricidal and repellent potential of M. oleifera extract. Five different concentrations (20, 10, 5, 2.5, and 1.25 %) of the ethyl acetate extract of M. oleifera were prepared to evaluate the acaricidal and repellent potential. Different parameters like adult tick mortality, larval mortality, egg hatchability, inhibition of egg hatchability, oviposition reduction, reproductive index, reproductive efficiency index, tick repellency, and product effectiveness were determined. Ethyl acetate extract of M. oleifera showed 70% adult mortality after 24 h treatment when 20% concentration was used. Similarly, 73% larval tick mortality was observed at 20% concentration. The results also showed the dose-dependent response of ethyl acetate extract of M. oleifera seeds against egg hatchability, inhibition of egg hatchability, oviposition reduction, reproductive index, reproductive efficiency index, and tick repellency, confirming that 20% concentration is effective as an acaricide and repellent against R. microplus. Therefore, the tested extract can be considered a possible candidate for controlling R. microplus in cattle. [ABSTRACT FROM AUTHOR]

Background: Tick-borne diseases are an emerging threat to public health throughout the temperate world, leading to a growing field of research aimed at developing and testing intervention strategies for reducing human-tick encounters or prevalence of infection in ticks. Various wide-spectrum chemical acaricides have proven effective for controlling tick populations, but many of these have potential deleterious side-effects on health and the environment. In addition to chemical acaricides, certain compounds such as diatomaceous earth have been shown to have physical acaricidal properties. We hypothesized that dolomitic lime (CaMg(CO3)2, a corrosive, desiccant mineral that is already used extensively in agricultural and forestry contexts to balance the pH of soils, may affect ticks' locomotory activity, habitat position, or survival and that this should manifest as a reduction in the number of questing ticks collected by dragging. Objective: This study aimed to formally assess this hypothesis in a controlled laboratory setting. Methods: We carried out a microcosm experiment, with one control and three treated microcosm trays, each replicating the natural substrate characterizing I. scapularis habitat in northeastern North America. Each tray was infested with 200 living larvae and 50 nymphs, and then treated with 0 (control), 50, 100, or 500 g/m2 of lime powder. Ticks were collected by microdragging 24 and 72 h postliming. Results: Efficacy of liming at reducing the number of collected questing ticks ranged from 87% to 100% for larvae and 0% to 69% for nymphs 24 h postliming and from 91% to 93% for larvae and −47% to 65% for nymphs 72 postliming. Conclusion: This study provides the first experimental evidence of the potential efficacy of liming for impairing activity of questing immature ticks. Given that lime is a low-cost material, that methods for widespread application in deciduous woodlands already exist, and that it has been documented as having a limited negative impact on the environment, further assessment of lime application as a public health risk reduction intervention for tick-borne diseases is warranted. [ABSTRACT FROM AUTHOR]

Copyright of Arab Journal of Plant Protection is the property of Arab Society for Plant Protection and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Simple Summary: Economically, Varroa destructor is the most important parasite to honey bees. There are many ways to deal with it, including pharmaceutical and biotechnological treatments. However, the mite has become resistant to many synthetic pesticides. There is little research on its response to organic acids. This report examines the question of whether it could become resistant to oxalic acid. The review uses literature from the past 30 years, and calculates and reviews the annual median efficacy for different application methods. If an efficacy of 70% or more is achieved, it can be concluded that the organism is not resistant. There is no evidence of resistance development, despite some outliers, which can be explained by the studies. Further tests are required to confirm the results. As Varroa destructor is one of the most important pathogens of Apis mellifera, there are numerous treatment methods, including pharmaceutical and biotechnological approaches. However, the rapid development of resistance to synthetic acaricides by Varroa destructor has become a significant concern. To date, there have been no investigations into the development of resistance to organic acids. This review examines the potential risk of oxalic acid resistance development by evaluating literature sources from the past 30 years following the PRISMA 2020 guidelines. Median annual efficacies are calculated and reviewed over time for several application methods. An efficacy higher than 70% is determined as not resistant. Independent of the method of application, no resistance development can be observed, although there are some outliers of the annual median. These outliers can be explained by brood status or study setting. However, the result is limited by the low number of efficacy values, and further standardised studies are needed. [ABSTRACT FROM AUTHOR]

Copyright of Environmental & Social Management Journal / Revista de Gestão Social e Ambiental is the property of Environmental & Social Management Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Sterility mosaic disease (SMD) presents a major challenge in pigeonpea cultivation throughout the Indian subcontinent. Chemical control methods, such as acaricides, are neither economically viable nor sustainable, making host plant resistance the preferred approach for managing this disease. In this study, we evaluated 45 pigeonpea germplasm accessions and breeding lines for SMD resistance over two consecutive Kharif seasons (2021-22 and 2022-23). Of the 45 genotypes tested, 8 exhibited low disease incidence (0-10%) (LRG-471, ICPL 151, ICPB 2089, ICPB 2047, ICPB 2092, ICPB 2211, ICPL 85063, and ICPL 14003) and were classified as resistant. Additionally, 23 genotypes showed disease incidence between 10.1-20.0% and were categorized as moderately resistant. These resistant genotypes offer promising new sources of SMD resistance and should be considered for inclusion in future pigeonpea breeding programs aimed at improving resistance. This research provides valuable phenotypic insights and identifies stable resistant sources essential for advancing SMD resistance breeding efforts. [ABSTRACT FROM AUTHOR]

The emergence of tick resistance against synthetic and eco-toxic chemical acaricides has stressed the need to find target-specific, non-toxic, and more potent alternatives such as botanicals. The current study was designed to investigate the acaricidal and repellent potential of ethyl acetate extract of Moringa oleifera seeds against Rhipicephalus microplus cattle ticks. Adult immersion test, larval immersion test, and tick climbing repellent assay were carried out to evaluate the acaricidal and repellent potential of M. oleifera extract. Five different concentrations (20, 10, 5, 2.5, and 1.25 %) of the ethyl acetate extract of M. oleifera were prepared to evaluate the acaricidal and repellent potential. Different parameters like adult tick mortality, larval mortality, egg hatchability, inhibition of egg hatchability, oviposition reduction, reproductive index, reproductive efficiency index, tick repellency, and product effectiveness were determined. Ethyl acetate extract of M. oleifera showed 70% adult mortality after 24 h treatment when 20% concentration was used. Similarly, 73% larval tick mortality was observed at 20% concentration. The results also showed the dose-dependent response of ethyl acetate extract of M. oleifera seeds against egg hatchability, inhibition of egg hatchability, oviposition reduction, reproductive index, reproductive efficiency index, and tick repellency, confirming that 20% concentration is effective as an acaricide and repellent against R. microplus. Therefore, the tested extract can be considered a possible candidate for controlling R. microplus in cattle.

Background: Acaricide resistance in cattle ticks is a significant concern in (sub)tropical regions, particularly Brazil. The Larval Packet Test (LPT) is the standard laboratory bioassay for resistance diagnosis, which requires triplicates of seven acaricidal dilutions plus controls to cover larval mortalities ranging between 0 and 100%. The value of the LPT lies in providing resistance ratios based on the ratio between the LC50 calculated with potentially resistant and susceptible ticks. However, LC50 ratios are difficult to translate into practical advice for farmers. Moreover, LPT requires laboratory facilities to maintain susceptible tick colonies, and it takes 6 weeks to obtain the larvae to be tested by LPT derived from engorged female ticks collected from cattle in the field. Our novel approach was twofold: first, we upgraded the LPT to the Resistance Intensity Test (RIT) by adopting the latest WHO guidelines for resistance detection in mosquitoes, which combines a 1 × recommended dose with 5 × and 10 × concentrated doses to reveal low, moderate and high resistance intensity, respectively. This reduced the number of test papers and tick larvae and, more importantly, provided relevant information on the resistance level. Our second innovative step was to abolish testing larvae entirely and expose partly engorged adult ticks to the same acaricidal doses immediately after removing them from cattle in the field. This resulted in the Rapid Tick exposure Test (RaTexT®), wherein partly engorged adult ticks were exposed to an acaricide-impregnated, specially designed matrix providing test results within 24 h. This approach directly compared resistance detection in tick larvae in the RIT with resistance in adult ticks in RaTexT®. Methods: Laboratory validation was conducted in Brazil with resistant and susceptible colonies of Rhipicephalus microplus ticks. For field validation, adult R. microplus ticks collected from different cattle farms in Brazil were evaluated for resistance to RaTexT®, and the results regarding their larval progenies were compared with those for the RIT. Partly engorged adult ticks derived from cattle infested with laboratory and field strains of R. microplus were exposed to deltamethrin in RaTexT® containers, which contained six rows of four interconnected compartments, accommodating five to eight semi-engorged female ticks with a preferred size ranging between 5 and 8 mm. The corresponding larvae of each strain were exposed in the RIT to the same deltamethrin concentrations in filter papers. Results: In RaTexT®, mortality in adult ticks from a resistant strain of R. microplus from Seropédica in Brazil was 38.4%, 54.2% and 75.0% at the 1 ×, 5 × and 10 × doses of deltamethrin, respectively. In RIT, mortality of larvae from the same resistant strain was 2.0%, 4.9% and 19.5% at 1 ×, 5 × and 10 × doses, respectively. The results of RaTexT® and RIT agreed since both tests identified a high level of resistance based on a cut-off of 90% mortality. In RaTexT®, mortality of adult ticks from a susceptible strain originating from Porto Alegre was 73.8%, 92.9% and 97.6% at the 1 ×, 5 × and 10 × doses, respectively. In RIT, mortality of larvae from the susceptible strain was 95.2%, 95.2% and 96.8% at the 1 ×, 5 × and 10 × doses, respectively. Interestingly, both tests identified a low number of unexpected resistant individuals in the susceptible strain since the mortality of neither larvae nor adults reached 100%. This effect remained unnoticed in the LPT, wherein a resistance ratio of 159.5 was found based on the LC50 of the resistant strain divided by the LC50 of the susceptible strain. Next, RaTexT® was compared with RIT using adult and larval ticks derived from three field strains of R. microplus in Brazil. RaTexT® detected high levels of resistance to deltamethrin in adult ticks in all strains, which was confirmed in larvae tested by the RIT. Both tests agreed on the same resistance level with significantly lower mortality rates in larvae than in adult ticks. Conclusions: RaTexT® is a novel rapid pen-site test for detecting acaricide resistance in adult livestock ticks. It potentially replaces laborious tests using larval ticks and provides results within 24 h relevant to acaricide resistance management of livestock ticks. [ABSTRACT FROM AUTHOR]

Plants are attacked by diverse herbivorous pests with different host specializations. While host plant resistance influences pest pressure, how resistance impacts the behaviors of generalist and specialist herbivores, and the relationship to resistance, is less well known. Here, we investigated the short-term (< 1 h) behavioral changes of a generalist herbivore, the two-spotted spider mite (TSM), and a specialist herbivore, the Banks grass mite (BGM), after introduction to no-choice Tanglefoot leaf-arenas (2 × 2 cm) of three maize inbred lines (B73, B75, and B96). The widely-used inbred line B73 is susceptible to spider mites, while B75 and B96 are known to be mite resistant, especially to TSM. Video tracking was used to record TSM and BGM walking, probing, feeding, resting, web-building and travel distance on arenas of each line. Mite oviposition was also recorded after 72 h. B75, a resistant line, decreased the feeding behavior (i.e., time) of both mite species compared to B73 (susceptible control) and B96. Moreover, TSM appeared to be sensitive to both resistant lines (B75 and B96) with reduced oviposition, and increased resting and web-building times compared to susceptible B73. In contrast, the specialist BGM showed no difference in oviposition, resting and web-building time across all maize inbred lines. Our findings of quite broad and short-term responses of TSM to B75 and B96 are consistent with a role for constitutive or rapidly induced plant defenses in maize in conferring TSM resistance. Other mechanisms of plant resistance may be needed, however, for defense against specialists like BGM. [ABSTRACT FROM AUTHOR]

Background: Pyrethroid chemicals are one of the main acaricides used against ticks. Resistance to these chemicals has been reported to be associated with mutations in the voltage-gated sodium channel (VGSC) gene of the Rhipicephalus microplus. This study investigates R. microplus resistance to pyrethroids in Guangxi region of China, marking one of the first research efforts in this area. The findings are intended to provide vital baseline for the effective implementation of localized tick control strategies. Methods: From March to July 2021, 447 R. microplus tick samples were collected from five prefecture-level cities in Guangxi. Allele-specific polymerase chain reaction (AS-PCR) was used to amplify segments C190A and G215T of the domain II S4-5 linker and T2134A of domain III S6 in the VGSC, to detect nucleotide mutations associated with resistance to pyrethroid acaricides. Subsequent analyses were conducted to ascertain the prevalence, types of mutations, and genotypic distributions within the sampled populations. Results: Mutations within VGSC gene were identified across all five studied populations of R. microplus, although the mutation rates remained generally low. Specifically, the most prevalent mutation was C190A, observed in 4.9% of the samples (22/447), followed by G215T at 4.0% (18/447), and T2134A at 1.3% (6/447). The distribution of mutations across three critical sites of the VGSC gene revealed four distinct mutation types: C190A, G215T, C190A + G215T, and T2134A. Notably, the single mutation C190A had the highest mutation frequency, accounting for 4.3%, and the C190A + G215T combination had the lowest, at only 0.7%. The analysis further identified seven genotypic combinations, with the wild-type combination C/C + G/G + T/T predominating at a frequency of 90.4%. Subsequently, the C/A + G/G + T/T combination was observed at a frequency of 4.3%, whereas the C/C + T/T + T/T combination exhibited the lowest frequency (0.2%). Additionally, no instances of simultaneous mutations at all three sites were detected. Geographical differences in mutation types were apparent. Both samples from Hechi to Chongzuo cities exhibited the same three mutation types; however, C190A was the most prevalent in Hechi, while G215T dominated in Chongzuo. In contrast, samples from Beihai to Guilin each exhibited only one mutation type: G215T occurred in 12.5% (4/32) of Beihai samples, and C190A in 7.5% (4/53) of Guilin samples. Conclusions: These findings underscore the relatively low frequency of VGSC gene mutations in R. microplus associated with pyrethroid resistance in the Guangxi, China. Moreover, the variation in mutation types and genotypic distributions across different locales highlights the need for regionalized strategies in monitoring and managing pyrethroid resistance in tick populations. This molecular surveillance is crucial for informing targeted control measures and mitigating the risk of widespread resistance emergence. [ABSTRACT FROM AUTHOR]

The honey bee (Apis mellifera) parasitic mite, Varroa destructor, is considered one of the main causes of colony losses in European honey bee (EHB) populations around the world. However, some EHB and Africanized honey bee (AHB) populations (derived from the African subspecies A. m. scutellata) that inhabit tropical and subtropical regions of the Americas, have survived varroa mite infestations in the absence of acaricide treatments. It is conceivable to expect that these honey bee populations, which have been subjected to natural selection over decades, would have developed resistance against V. destructor or possess pre-existing adaptations that allow them to survive mite parasitism. Here, we present a comprehensive literature review describing the spread of V. destructor and the honey bee populations occurring in Latin America (LA), and summarize the evidence of resistance of those populations to V. destructor. We also analyze reports describing the potential mechanisms of mite resistance and how they operate in those honey bee populations. Studies of a few EHB, as well as of numerous AHB populations exhibiting resistance to V. destructor in LA, unveil the existence of evolutionary adaptations that restrain V. destructor population growth and provide insight into the current host-parasite relationship. This review supports the notion that selective breeding of local honey bee populations from LA could be a viable strategy to manage varroa mite infestations in colonies. [ABSTRACT FROM AUTHOR]

The twospotted spider mite (TSSM), Tetranychus urticae Koch (Acari: Tetranychidae) is a major pest of field and greenhouse crops leading to qualitative and quantitative losses. Various chemical‐based acaricides are being used for its management that pose risks to human health, environment and non‐targeted organisms besides the development of resistance and resurgence of the pests. Therefore, alternative mite management practices are being promoted and implemented. Amongst them, entomopathogenic fungi (EPF) like Beauveria bassiana and Metarhizium spp. are being used globally, although new alternative EPF are required. Keeping this in mind, the present study was comprehended to determine the pathogenicity of native EPF, viz., Tolypocladium inflatum (Hypocreales: Ophiocordycipitaceae) and Clonostachys krabiensis (Hypocreales: Bionectriaceae) against different life stages of TSSM under laboratory conditions. The results indicated that adults are more vulnerable to studied fungi followed by nymphs and eggs of TSSM. The combined application of T. inflatum and C. krabiensis was significantly effective in controlling TSSM adults (99.33%) followed by T. inflatum (93.34%) and C. krabiensis (85.33%). According to the probit analysis, the combined application of studied EPF was found to be more effective against TSSM adults (LC50 = 6.72 × 104 conidia/mL) followed by T. inflatum (LC50 = 1.92 × 106 conidia/mL) and C. krabiensis (LC50 = 7.90 × 106 conidia/mL). All three treatments at higher concentrations significantly reduced the adult and nymph populations. Morphological investigations using scanning electron microscopy revealed the successful conidial adhesion, germination and penetration of native T. inflatum and C. krabiensis conidia on TSSM adults. Thus, the acaricidal potential of isolated native fungi can further be explored for developing fungal‐based formulations for the sustainable management of mites. [ABSTRACT FROM AUTHOR]

An experiment was conducted during March-April, 2018-19 and 2019-20 in the Department of Agricultural Entomology, Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar, West Bengal, India to evaluate the duration of residual toxicity of five conventional as well as recently introduced acaricides against red spider mite, Oligonychus coffeae on tea. Five acaricides having different mode of actions were selected for the present study. Fenazaquin10 EC, propargite 57 EC, hexythiazox 5.45 EC, spiromesifen 22.9SC and cyflumetofen 20SC were sprayed @ 100, 430, 15,96 and 125 g a.i. ha-1, respectively. Treated leaves were collected from the field and bioassay experiments were conducted in the laboratory. The results revealed that cyflumetofen 20 SC persisted for a longer duration (28 days) with the highest PT value (2347.24) whereas, propargite 57 EC persisted for a relatively short duration (22 days) with lesser PT values (1678.93). Higher LT50 values of 23.83 and 24.26 days were also observed in case of cyflumetofen 20 SC @ 125 g a.i. ha-1 during 1st and 2nd years of study, respectively. The lowest LT50 value was observed in propargite 57 EC @ 430 g a.i. ha-1. Spiromesifen 22.9 SC was found to be the second-best treatment and it showed the LT50 value 22.34 and 22.42 days during 1st and 2nd year of study, respectively. [ABSTRACT FROM AUTHOR]

Background: The pigeonpea eriophyid mite, Aceria cajani Chan., vector of sterility mosaic disease in pigeonpea, causes economic damage of up to 90% during the early stages of crop growth. The major element in deploying management practice is to know the population dynamics of the pest. Generally, the vectors of disease causing agents were managed with the synthetic chemical. So we have taken studies to know efficacy of insecticides and acaricides in its control on pigeonpea. Methods: The population dynamics of A. cajani Chan. was monitored in field plots from January 2021 to December 2021. For efficacy of insecticides and acaricides studies in control of A. cajani a completely randomized design was organized. Twelve treatments (insecticides/acaricides) were tested against A. cajani on pigeonpea [var. ICP 8863 (Shree Maruti]. Result: This study found that mite population reached a peak in the summer (March) and another peak in the post-monsoon period (October), whereas the lowest populations were recorded in winter (January). Correlation studies exhibited a significant positive correlation with both maximum and minimum temperature. The insecticide and acaricide trials on A. cajani found that all chemicals used were effective and entomopathogenic formulations were comparatively less effective. [ABSTRACT FROM AUTHOR]

Varroa destructor is a dangerous pest directly for beekeeping and indirectly for crops that require insect pollination. In recent years, the application of chemical pesticides has led to the occurrence of mite resistance and contamination of hive products. Plant extracts are considered as a suitable alternative to chemical acaricides for the Varroa mite control. Therefore, the present study aimed to investigate the acaricidal and insecticidal activity of extract of Prangos ferulacea plant against the Varroa mite and its host in the honey bee colonies in the climatic conditions of Kurdistan province from 2022 to 2024. The P. ferulacea plant was collected in June 2022 from different regions of Kurdistan province in the flowering stage, extracted and then its chemical compounds were identified using GC-MS. The present study was conducted in the form of a factorial experiment based on a completely random basic design with four treatments and seven replications. Before conducting the bioassay experiments, the experimental colonies were homogenized in terms of queen age, population (adults and brood), and honey storage. Also, the initial infestation rate of colonies with Varroa mites was evaluated for adult and brood. The results showed that the extract of 50% of P. ferulacea was relatively favorable acaricidal properties. So that, there was no significant difference with oxalic acid and Apistan treatments in terms of mite mortality percentage in the first time of spraying. Also, the result showed that the bee's mortality percentage was not more than 7% in any of the times of spraying with the 50% extract of the P. ferulacea, and there was observed a significant difference compared to the oxalic acid and Apistan treatments in terms of bee's mortality percentage (P<0.01). The queen superseding was not observed in any of the experimental treatments. According to the findings of the present research, the concentration of 50% of the extract P. ferulaceous can be suggested as a suitable alternative to synthetic acaricides and organic acids to control the Varroa mite in honey bee colonies. [ABSTRACT FROM AUTHOR]

Dermatophagoides farinae is a major source of allergens that are the cause of allergic diseases in humans. Methyl isoeugenol (MIE) is a naturally occurring compound in plants and its strong acaricidal toxicity has been established; however, the mechanism behind its acaricidal properties remains unclear. In this study, to investigate the action mechanism of MIE on D. farinae the isobaric tags for relative and absolute quantification (iTRAQ) proteomics method is used. Protein samples were extracted from D. farinae before and after 24 h of MIE treatment for iTRAQ technique analysis. Bioinformatics analysis revealed that most differentially expressed proteins were located in the cytoplasm, impacting cytoplasmic function. Additionally, Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed significant enrichment of the differential proteins in the cellular autophagy signalling pathway. The autophagy-related proteins Autophagy-Related Protein 3 (ATG3) and Cathepsin L (CTSL) were up-regulated, disrupting the autophagic process. We found that the main action mechanism of MIE against D. farinae might be cellular autophagy. The transcriptional validation of six differential proteins demonstrated consistent expression trends with the proteomics data. This study reveals the acaricidal mechanism of MIE for the first time and lays the foundation for further research on D. farinae control. [ABSTRACT FROM AUTHOR]

In order to obtain acaricides of pyrazole acrylonitrile with better acaricidal activity for mitecontrol, seventeen novel ester derivatives were synthesized via four steps of Blanc chloromethylation reaction, dehalogenation reaction, condensation reaction and esterification reaction using ethyl 1,3-dimethyl-1H-pyrazole-5-carboxylate as the starting material. Furthermore, their acaricidal activity against Tetranychus cinnabarinus was assessed by immersion test, and the mortality rate and lethal midrange concentration LC50 were calculated. The results show that the target compounds display excellent acaricidal activity against T. cinnabarinus, and compared with the commercial pesticide cyenopyrafen (LC50 = 0.61 mg/L), compounds 5q and 5k possess significantly higher acaricidal activity against T. cinnabarinus with LC50 values of 0.17 and 0.22 mg/L, respectively. [ABSTRACT FROM AUTHOR]

Background: The control and prevention of ticks and tick borne diseases (TBDs) is often difficult, since it is necessary to disrupt a complex transmission cycle, involving ticks and vertebrate hosts, which interact in a changing environment, driven by constant environmental and ecological changes. Our view is that factors driving the spread of R. microplus are complex and intrinsically interconnected, something that has often been ignored in control strategies. Results: The aim of this review is to analyze the importance of the epidemiological surveillance of ticks and tick-borne diseases (TTBDs) for Public Health, with the One Health approach; emphasizing the knowledge, importance, and distribution of TTBDs. Conclusions: The key points for surveillance, and raising the scope and limitations of surveillance programs, to delay the emergence of acaricide resistance, to reduce toxic residues in food for human consumption and to protect animal, human, and environmental health, from a One Health perspective will require calling producers, veterinarians, academics, pharmaceutical industry, and decision makers to join efforts in order to mitigate the effects of ticks and TBDs affecting the cattle industry in Mexico. [ABSTRACT FROM AUTHOR]

One of the most damaging pests of agricultural crops across the globe is the two-spotted spider mite, Tetranychus urticae Koch. A wide variety of arthropods and plant pathogens can be controlled by essential oils, which are secondary metabolites produced by plants. It is possible to enhance the stability as well as the anti-pest efficiency of plant essential oils by encapsulation. Water distillation was used to extract the essential oils from Eucalyptus globulus and Ferula assafoetida. The chitosan nanoparticles were used to load both essential oils into nanoformulations. Studies were conducted on T. urticae life table characteristics under experimental circumstances to determine the sublethal impacts of essential oils and their nanoformulations. Intrinsic growth rate (r) for population exposed to E. globulus, F. assafoetida essential oils, their nanoformulations and the control were 0.1, 0.069, 0.051, 0.018 and 0.21 per day, respectively. F. assafoetida and E. globulus nanoformulations resulted the lowest fecundity compared to the other treatments. According the result of the lethal and sublethal effects of purified essential oils and nanoformulations of F. assafoetida and E. globulus, they would be recommended for controlling the two-spotted spider mites, T. urticae. [ABSTRACT FROM AUTHOR]

Phytoseiulus longipes is a predatory mite of Tetranychus evansi, which is an invasive pest in Africa and elsewhere. The introduction of this predator in Africa has considerable potential, but little is known about the compatibility of P. longipes with commonly used pesticides. Here, we examined lethal and sublethal effects of two pyrethroids (cypermethrin and deltamethrin), two organophosphates (dimethoate and chlorpyrifos), one nicotinoid (imidacloprid), two acaricides (propargite and abamectin), two naturally derived pesticides (oxymatrine and azadirachtin), and one entomopathogenic fungal-based formulation (Hirsutella thompsonii) on P. longipes eggs and adults. The pesticides were sprayed at their maximum recommended concentrations. Topical exposures to azadirachtin, imidacloprid, propargite, abamectin, oxymatrine, and H. thompsonii significantly reduced the net reproductive rate (R0), intrinsic rate of increase (r) and finite rate of increase (λ)of P. longipes. Pesticide lethal and sublethal effects on the predator were summarized in a reduction coefficient (Ex) for the classification based on IOBC toxicity categories. Results revealed that Azadirachtin and H. thompsonii were slightly harmful effects to adults. Imidacloprid, propargite, abamectin, and oxymatrine were moderately harmful to both eggs and adults. Residual persistence bioassays revealed that 4-day-old residue of azadirachtin had no harmful effect on the predator. Abamectin, oxymatrine, and H. thompsonii became harmless to it 10 days post-spraying, and propargite and imidacloprid were considered harmless after 20 days. Cypermethrin, deltamethrin, dimethoate, and chlorpyrifos were highly harmful to both eggs and adults, persistence remaining high even after 31 days of application. These findings provide valuable insights into decision-making when considering P. longipes for use in IPM programs. [ABSTRACT FROM AUTHOR]

The adoption of the European Green Deal will limit acaricide use in high value crops like raspberry, to be replaced by biological control and other alternative strategies. More basic knowledge on mites in such crops is then necessary, like species, density, and their role as vectors of plant diseases. This study had four aims, focusing on raspberry leaves at northern altitude: (1) identify mite species; (2) study mite population densities; (3) investigate mite intra-plant distribution; (4) investigate co-occurrence of phytophagous mites, raspberry leaf blotch disorder and raspberry leaf blotch virus (RLBV). Four sites in south-eastern Norway were sampled five times. Floricanes from different parts of the sites were collected, taking one leaf from each of the upper, middle, and bottom zones of the cane. Mites were extracted with a washing technique and processed for species identification and RLBV detection. Mites and leaves were tested for RLBV by reverse transcription polymerase chain reaction (RT-PCR) with virus-specific primers. Phytophagous mites, Phyllocoptes gracilis, Tetranychus urticae, and Neotetranychus rubi, and predatory mites, Anystis baccarum and Typhlodromus (Typhlodromus) pyri were identified. All phytophagous mites in cultivated raspberry preferred the upper zone of floricanes, while in non-cultivated raspberry, they preferred the middle zone. The presence of phytophagous mites did not lead to raspberry leaf blotch disorder during this study. RLBV was detected in 1.3% of the sampled plants, none of them with leaf blotch symptoms, and in 4.3% of P. gracilis samples, and in some spider mite samples, implying that Tetranychids could also be vectors of RLBV. [ABSTRACT FROM AUTHOR]

Florida's strawberry industry is currently valued at $511 million annually but faces challenges from pathogens and arthropod pests especially Tetranychus urticae Koch (twospotted spider mite) and Scirtothrips dorsalis Hood (chilli thrips). Predatory mites, particularly Neoseiulus cucumeris Oudemans, Neoseiulus californicus McGregor, and Amblyseius swirskii Athias-Henriot, play a crucial role in pest management. However, there are concerns regarding how these biological control agents are affected by fungicides used in current pathogen management strategies. This study assessed the residual effects of commonly used fungicides in strawberries on the survival, feeding, and oviposition of these predatory mites. Commercially sourced predatory mites were reared on S. dorsalis larvae, and gravid female predators placed on fungicide treated strawberry leaf discs in a Munger cell for 120 h. Fungicides tested included two formulations of Captan, hydrogen peroxide + peroxyacetic acid, cyprodinil + fludioxonil, tetramethylthiuram disulfide, cyflufenamid and a control. All fungicides tested had an impact on the survival, feeding, and oviposition of the predators. Among the fungicide treatments, the lowest predator survival was observed in the cyprodinil + fludioxonil treatment, while the highest was observed in the hydrogen peroxide + peroxyacetic acid and tetramethylthiuram disulfide treatments. In all treatments, feeding and oviposition greatly varied among predators; specifically, N. cucumeris and A. swirskii had the lowest prey consumption, while N. californicus had the highest. These findings highlight the potential incompatibility between fungicides and predatory mites and demonstrate the need for the development of a fungicide rotation program tailored to the different susceptibilities of predators to fungicides. [ABSTRACT FROM AUTHOR]

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This article discusses the use of oligonucleotide insecticides, specifically contact unmodified antisense DNA (CUAD) biotechnology, for pest control in agriculture. The insecticides target specific regions of pests' RNA, leading to their mortality. The research shows that these insecticides have been effective in reducing pest populations and are safe for non-target organisms and the environment. The article also highlights the potential of CUAD biotechnology for agronomy. Additionally, the document provides a list of references that explore the effectiveness of DNA insecticides against various insect pests and their potential benefits compared to traditional insecticides. [Extracted from the article]

Background: Canine acaricides with rapid onset and sustained activity can reduce pathogen transmission risk and enhance pet owner experience. This randomized, complete block design, investigator-masked study compared the speed of kill of Amblyomma americanum provided by three monthly-use isoxazoline-containing products. Methods: Eight randomized beagles per group were treated (day 0), per label, with sarolaner (combined with moxidectin and pyrantel, Simparica Trio™), afoxolaner (NexGard™), or lotilaner (Credelio™), or remained untreated. Infestations with 50 adult A. americanum were conducted on days − 7, − 2, 21, and 28, and tick counts were performed on day − 5 (for blocking), and at 4, 8, 12, 24, 48, and 72 h following treatment and subsequent infestations. Efficacy calculations were based on geometric mean live tick counts. A linear mixed model was used for between-group comparisons. Results: On day 0, only lotilaner significantly reduced an A. americanum infestation by 12 h (43.3%; P = 0.002). Efficacy of lotilaner and afoxolaner at 24 h post-treatment was 95.3% and 97.6%, respectively, both significantly different from sarolaner (74%) (P = 0.002, P < 0.001, respectively). On day 21, at 12 h postinfestation, lotilaner efficacy (59.6%) was significantly different from sarolaner (0.0%) (P < 0.001) and afoxolaner (6.3%) (P < 0.001). At 24 h, lotilaner efficacy (97.4%) was significantly different (P < 0.001) from sarolaner and afoxolaner (13.6% and 14.9%, respectively). On day 28, at 12 h postinfestation, lotilaner efficacy (47.8%) was significantly different from sarolaner (17.1%) (P = 0.020) and afoxolaner (9.0%) (P = 0.006). At 24 h, lotilaner efficacy (92.3%) was significantly different from sarolaner 4.9% (P < 0.001) and afoxolaner (0.0%) (P < 0.001). Speed of kill for sarolaner and afoxolaner, but not lotilaner, significantly declined over the study period. Following reinfestation on day 28, neither sarolaner nor afoxolaner reached 90% efficacy by 48 h. By 72 h, sarolaner efficacy was 97.4% and afoxolaner efficacy was 86.3%. Only lotilaner achieved ≥ 90% efficacy by 24 h post-treatment and 24 h postinfestation on days 21 and 28. Time to ≥ 90% efficacy following new infestations consistently occurred 24–48 h earlier for lotilaner compared with sarolaner or afoxolaner. Conclusions: Credelio (lotilaner) has a more rapid onset of acaricidal activity against A. americanum than Simparica Trio (sarolaner-moxidectin-pyrantel) and NexGard (afoxolaner). Only lotilaner's speed of tick kill is sustained throughout the dosing period. [ABSTRACT FROM AUTHOR]

Background: Production of entomopathogenic fungi on a solid substrate, mostly on rice, is preferred by many producers due to its low technological requirements. Drying may be needed after fermentation to preserve the viability of the conidia until use. This study aimed to introduce some uncomplicated drying techniques and study their effectiveness in terms of drying time and extent, as well as their impact on the quantity of conidia produced and their biological activity. Four techniques were studied, i.e., condensing water vapor (by cooling), desiccant (using NaOH), air drying on a net, and air drying on a solid (impermeable) surface. Results: Condensing water vapor and desiccant techniques were the fastest and most efficient, resulting in the lowest moisture content, ranging between 12 and 13%. While drying on a solid surface was the slowest and resulted in the highest moisture content of 32.98%. All of the dried samples yielded a lower quantity of conidia compared to the fresh samples. Samples of condensing water vapor, desiccant, and net techniques yielded approximately a similar quantity of conidia, ranging between 74 and 71% of the yield of the fresh sample. The solid surface sample yielded the lowest quantity of conidia, representing 63.78% of the fresh sample yield. A bioassay test on the mite, Tetranychus urticae Koch (Acari: Tetranychidae), showed that conidia dried via condensing water vapor and desiccant techniques kept their pathogenicity similar to the fresh sample, while samples dried on a net and solid surface significantly lost part of their pathogenicity. Conclusion: The condensing water vapor and desiccant techniques were the most efficient regarding the time needed, conidia yield, and pathogenicity. Drying on a solid surface was the least effective regarding the same factors. [ABSTRACT FROM AUTHOR]