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Phytoseiid predatory mites are one of the most important groups of biocontrol agents, commonly used in biological control. The ability to produce these predatory mites economically, at high density on cheap factitious food sources, is a major contributor to their success. Astigmatid mites are the most widely used factitious food for this purpose. In this study, we investigated the potential application of the leaf-dwelling astigmatid mite Czenspinskia transversostriata (Oudemans) (Acari: Winterschmidtiidae) as a prey mite in biological control. We tested whether C. transversostriata is a suitable food source for the predatory mite Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae), both in the laboratory and on cucumber plants. Based on a reproduction trial, C. transversostriata proved to be an equally good food source compared to both pollen of Typha angustifolia L. (Poales: Typhaceae) and a frequently used prey mite Carpoglyphus lactis L. (Acari: Carpoglyphidae). In a pre-establishment trial on cucumber plants, populations of A. swirskii reached equally high densities when supplemented with C. transversostriata, compared to C. lactis. Lastly, we show that C. transversostriata is capable of feeding and reproducing on powdery mildew growing on cucumber plants, thereby slowing down the development of the pathogenic fungus. Results derived from this study show that C. transversostriata may have multiple potential applications in biological control programs. [ABSTRACT FROM AUTHOR]

This study explores sustainable agricultural practices by examining the role of organic materials in enhancing native predatory mites for controlling spider mites in apple orchards. Developing techniques to conserve indigenous natural enemies is vital for sustainable agricultural production. Phytoseiid mites can control spider mites, which are among the most significant pests in apple production. To conserve phytoseiid mite populations, it is important to identify alternative prey and to determine their role in phytoseiid mite proliferation. We demonstrated that the concurrent use of specific organic fertilizers and coconut husks can increase prey Tyrophagus mites, thereby enhancing phytoseiid mite density. Our research was conducted using sticky traps at the Miyagi Prefectural Agriculture and Horticulture Research Center in Japan. The occurrence of Tyrophagus mites was significantly correlated with the occurrence of phytoseiid mites in 2 years. In laboratory experiments, the use of organic fertilizers increased the density of Tyrophagus mites by 83 × within 4 weeks. Several species of phytoseiid mites were able to lay between 0.25 and 1.03 eggs per day per female by preying on Tyrophagus larvae. A 2-year field survey revealed that the use of organic fertilizers more than doubled the density of phytoseiid mites on apple leaves, likely through promoting Tyrophagus mite proliferation on the ground. These results highlight the potential of organic fertilizers not only to enhance soil nutrients, but also to boost phytoseiid mite populations, thereby contributing to more sustainable apple production. [ABSTRACT FROM AUTHOR]

Tomato crops are attacked by several pests, including mites. While the main predatory mites are not effective enough to control mite pests, recent studies have shown encouraging results with the European endemic phytoseiid Typhlodromus (Anthoseius) recki. The first objective of the study was to assess the ability of this species to disperse along the tomato stem, considering six genotypes of Solanum lycopersicum, S. peruvianum and S. cheesmaniae with contrasted trichome numbers and types of stem trichomes, accuratetly characterised in a previous study. The second objective was to determine how predator morphological traits can explain dispersal along the tomato stem. For this, ambulatory dispersal ability of females (stem crossing rate success, hesitation and escape behavior, mobility periods) was tested in lab conditions on the eight Solanum genotypes, at four period of time after the predator introduction (10, 25, 55 and 100 min), with a video observation of 5 min at each period. The females were then mounted on slides and body length and width (at the fore hind, middle and back parts) measured. No effect of the tomato genotypes was observed on the dispersal ability of the predator. However, specimens that succeeded in crossing the stem, had a higher percentage of mobility time (79.36%) than those that failed (43.60%). Furthermore, body width at midbody (DSW2) and dorsal shield length (DSL) were negatively correlated with dispersal ability. The mean DSL and DSW2 of the females that succeed to cross were 342.3 and 160.9 μm, respectively vs. 345.6 and 164.9 μm, for females that did not succeed. This suggests that the more slender and relatively small the specimens, the more are mobile and able to successfully cross the stem. The number of glandular trichomes type (GT) VI and to a lesser extent GT I and IV, and non-glandular trichomes (NGT) II&III appear to limit dispersal. The GT VI seems to have a repellent effect. On the opposite, the number of NGT V were positively correlated with high mobility and stem crossing rates. Assuming that the main barrier to biological control efficiency is dispersal along tomato stems, these preliminary results should have implications for biological control success. The proportion of mites with 'optimal dimensions' appears to be low and further studies should be undertaken to better assess the proportion of mites with such ideal dimensions in different populations and also to determine whether these morphological traits are associated with different feeding abilities and/or abiotic conditions. [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]

BACKGROUND: The Varroa mite (Varroa destructor) is considered to be the greatest threat to apiculture worldwide. RNA interference (RNAi) using double‐stranded RNA (dsRNA) as a gene silencing mechanism has emerged as a next‐generation strategy for mite control. RESULTS: We explored the impact of a dsRNA biopesticide, named vadescana, designed to silence the calmodulin gene in Varroa, on mite fitness in mini‐hives housed in a laboratory. Two dosages were tested: 2 g/L dsRNA and 8 g/L dsRNA. Vadescana appeared to have no effect on mite survival, however, mite fertility was substantially reduced. The majority of foundress mites exposed to vadescana failed to produce any offspring. No dose‐dependent effect of vadescana was observed, as both the low and high doses inhibited mite reproduction equally well in the mini‐hives and neither dose impacted pupal survival of the honey bee. Approximately 95% of bee pupae were alive at uncapping across all treatment groups. CONCLUSION: These findings suggest that vadescana has significant potential as an effective alternative to conventional methods for Varroa control, with broader implications for the utilization of RNAi as a next‐generation tool in the management of pest species. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: Most studies on efficacy of fungal pathogens and predatory mites against Tetranychus urticae have been done on individual species in the laboratory. We evaluated fungi and predatory mites separately and together against glasshouse populations of T. urticae on chrysanthemum plants. First, effectiveness of the fungal pathogens Beauveria bassiana (Bb88) and Metarhizium anisopliae (Ma129) was compared; then, effectiveness of the predatory mites Phytoseiulus persimilis and Neoseiulus californicus. Based on the results, N. californicus and isolate Ma129 were selected and evaluated in combination. In all experiments, treatment effects were assessed for eggs and motile stages of T. urticae. RESULTS: The first experiment showed no significant effect of either fungal isolate on T. urticae populations, except on plants initially infested with 20 mites, where more eggs were found in the control compared to the fungal treatments. In the second experiment, both predatory mites were equally effective at reducing T. urticae populations compared with the control, regardless of initial T. urticae population density. The last experiment demonstrated that populations of T. urticae were reduced most when M. anisopliae (Ma129) and N. californicus were applied together, compared with the control and when each natural enemy was applied separately. CONCLUSIONS: Metarhizium anisopliae (Ma129) and B. bassiana (Bb88) isolates did not have a significant effect on reducing T. urticae populations. Both predatory mites reduced T. urticae populations, regardless of T. urticae density. Combined application of M. anisopliae (Ma129) and N. californicus were more effective against T. urticae than the control or when each agent was applied separately. © 2024 Society of Chemical Industry. [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]

The mite Varroa destructor Anderson and Trueman (Mesostigmata: Varroidae) has a dramatic impact on beekeeping and is one of the main causes of honey bee colony losses. This ectoparasite feeds on honey bees' liquid tissues, through a wound created on the host integument, determining weight loss and a reduction of lifespan, as well as the transmission of viral pathogens. However, despite its importance, the mite feeding strategy and the host regulation role by the salivary secretions have been poorly explored. Here, we contribute to fill this gap by identifying the salivary components of V. destructor, to study their functional importance for mite feeding and survival. The differential expression analysis identified 30 salivary gland genes encoding putatively secreted proteins, among which only 15 were found to be functionally annotated. These latter include proteins with putative anti‐bacterial, anti‐fungal, cytolytic, digestive and immunosuppressive function. The three most highly transcribed genes, coding for a chitin‐binding domain protein, a Kazal domain serine protease inhibitor and a papain‐like cysteine protease were selected to study their functional importance by reverse genetics. Knockdown (90%–99%) by RNA interference (RNAi) of the transcript of a chitin‐binding domain protein, likely interfering with the immune reaction to facilitate mite feeding, was associated with a 40%–50% decrease of mite survival. This work expands our knowledge of the host regulation and nutritional exploitation strategies adopted by ectoparasites of arthropods and allows the identification of potential targets for RNAi, paving the way towards the development of new strategies for Varroa mite control. [ABSTRACT FROM AUTHOR]

Phytoseius plumifer (Canestrini and Fanzago) and Euseius scutalis (Athias-Henriot) (Phytoseiidae) are generalist predatory mites important in controlling phytophagous mites on some agricultural crops. The biology of both species as potential biological control agents of the grape erineum mite, Colomerus vitis (Pagenstecher) (Eriophyidae) on grape leaf disks was studied in the laboratory at 33 ± 1 °C, 60%RH, 12:12 h L:D. The developmental time, survival, and reproductive parameters of P. plumifer and E. scutalis on C. vitis, date palm pollen as well as C. vitis plus date palm pollen were investigated. Both predators, P. plumifer and E. scutalis, thrived on the mixed diet of C. vitis and date palm pollen resulting in a shorter developmental time (6.16 and 6.69 days, respectively), higher oviposition rate (2.11 and 1.96 eggs/female/day, respectively), and higher intrinsic rate of increase (0.251 and 0.229 per female/day, respectively) than on any other diet. Date palm pollen was an adequate alternative food source for P. plumifer and E. scutalis. The results suggest that both predators have good potential to suppress C. vitis populations and that date palm pollen can support the population establishment of both predators in the absence or scarcity of the main prey in the environment. We discuss the relevance of our results for the biocontrol of C. vitis. [ABSTRACT FROM AUTHOR]

Insecticide resistance in Panonychus citri is a major obstacle to mite control in citrus orchards. Pyrethroid insecticides are continually used to control mites in China, although resistance to pyrethroids has evolved in some populations. Here, the resistance to the pyrethroid fenpropathrin was investigated and 7 out of 8 field‐collected populations of P. citri exhibited a high level of resistance, ranging from 171‐fold to 15 391‐fold higher than the susceptible (SS) comparison strain. Three voltage‐gated sodium channel (VGSC) mutations were identified in the tested populations: L1031V, F1747L, and F1751I. Amplicon sequencing was used to evaluate the frequency of these mutations in the 19 field populations. L1031V and F1751I were present in all populations at frequencies of 11.6%–82.1% and 0.5%–31.8%, respectively, whereas the F1747L mutation was only present in 12 populations from Chongqing, Sichuan, Guangxi, and Yunnan provinces. Introduction of these mutations singly or in combination into transgenic flies significantly increased their resistance to fenpropathrin and these flies also exhibited reduced mortality after exposure to the pyrethroids permethrin and β‐cypermethrin. Panonychus citri VGSC homology modeling and ligand docking indicate that F1747 and F1751 form direct binding contacts with pyrethroids, which are lost with mutation, whereas L1031 mutation may diminish pyrethroid effects through an allosteric mechanism. Overall, the results provide molecular markers for monitoring pest resistance to pyrethroids and offer new insights into the basis of pyrethroid actions on sodium channels. [ABSTRACT FROM AUTHOR]

The survival of the honey bee (Apis mellifera), which has a crucial role in pollination and ecosystem maintenance, is threatened by many pathogens, including parasites, bacteria, fungi and viruses. The ectoparasite Varroa destructor is considered the major cause of the worldwide decline in honey bee colony health. Although several synthetic acaricides are available to control Varroa infestations, resistant mites and side effects on bees have been documented. The development of natural alternatives for mite control is therefore encouraged. The study aims at exploring the effects of cinnamon and oregano essential oils (EOs) and of a mixed fruit cocktail juice on mite infestation levels and bee colony health. A multi-method study including hive inspection, mite count, molecular detection of fungal, bacterial and viral pathogens, analysis of defensin-1, hymenoptaecin and vitellogenin immune gene expression, colony density and honey production data, was conducted in a 20-hive experimental apiary. The colonies were divided into five groups: four treatment groups and one control group. The treatment groups were fed on a sugar syrup supplemented with cinnamon EO, oregano EO, a 1:1 mixture of both EOs, or a juice cocktail. An unsupplemented syrup was, instead, used to feed the control group. While V. destructor affected all the colonies throughout the study, no differences in mite infestation levels, population density and honey yield were observed between treatment and control groups. An overexpression of vitellogenin was instead found in all EO-treated groups, even though a significant difference was only found in the group treated with the 1:1 EO mixture. Viral (DWV, CBPV and BQCV), fungal (Nosema ceranae) and bacterial (Melissococcus plutonius) pathogens from both symptomatic and asymptomatic colonies were detected. [ABSTRACT FROM AUTHOR]

The life cycle of Varroa destructor , the ectoparasitic mite of honey bees (Apis mellifera), includes a dispersal phase, in which mites attach to adult bees for transport and feeding, and a reproductive phase, in which mites invade worker and drone brood cells just prior to pupation to reproduce while their bee hosts complete development. In this study, we wanted to determine whether increased nurse bee visitations of adjacent drone and worker brood cells would increase the likelihood of Varroa mites invading those cells. We also explored whether temporarily restricting the nurses' access to sections of worker brood for 2 or 4 h would subsequently cause higher nurse visitations, and thus, higher Varroa cell invasions. Temporarily precluding larvae from being fed by nurses subsequently led to higher Varroa infestation of those sections in some colonies, but this pattern was not consistent across colonies. Therefore, removing highly infested sections of capped worker brood could be further explored as a potential mechanical/cultural method for mite control. Our results provide more information on how nurse visitations affect the patterns of larval cell invasion by Varroa. Given that the mite's successful reproduction depends on the nurses' ability to visit and feed developing brood, more studies are needed to understand the patterns of Varroa mite invasion of drone and worker cells to better combat this pervasive honey bee parasite. [ABSTRACT FROM AUTHOR]

Varroa destructor Oud (Acari: Varroidae) is a harmful ectoparasite of Apis mellifera L. honey bees causing widespread colony losses in Europe and North America. To control populations of these mites, beekeepers have an arsenal of different treatments, including both chemical and nonchemical options. However, nonchemical treatments can be labor intensive, and Varroa has gained resistance to some conventional pesticides, and the use of other chemical treatments is restricted temporally (e.g. cannot be applied during periods of honey production). Thus, beekeepers require additional treatment options for controlling mite populations. The compound 1-allyloxy-4-propoxybenzene (3c { 3,6 }) is a diether previously shown to be a strong feeding deterrent against Lepidopteran larvae and a repellent against mosquitoes and showed promise as a novel acaricide from laboratory and early field trials. Here we test the effect of the compound, applied at 8 g/brood box on wooden release devices, on honey bees and Varroa in field honey bee colonies located in Maryland, USA, and using a thymol-based commercial product as a positive control. 3c { 3,6 } had minimal effect on honey bee colonies, but more tests are needed to determine whether it affected egg production by queens. Against Varroa 3c { 3,6 } had an estimated efficacy of 78.5%, while the positive control thymol product showed an efficacy of 91.3%. 3c { 3,6 } is still in the development stage, and the dose or application method needs to be revisited. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Entomology is the property of Chinese Journal of Applied Entomology, Editorial Department 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.)

Copyright of Chinese Journal of Applied Entomology is the property of Chinese Journal of Applied Entomology, Editorial Department 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.)

Copyright of Chinese Journal of Applied Entomology is the property of Chinese Journal of Applied Entomology, Editorial Department 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.)

Mites are highly prevalent arthropods that infest diverse ecological niches globally. Approximately 55,000 species of mites have been identified but many more are yet to be discovered. Of the ones we do know about, most go unnoticed by humans and animals. However, there are several species from the Acariformes superorder that exert a significant impact on global human health. House dust mites are a major source of inhaled allergens, affecting 10–20% of the world's population; storage mites also cause a significant allergy in susceptible individuals; chiggers are the sole vectors for the bacterium that causes scrub typhus; Demodex mites are part of the normal microfauna of humans and their pets, but under certain conditions populations grow out of control and affect the integrity of the integumentary system; and scabies mites cause one of the most common dermatological diseases worldwide. On the other hand, recent genome sequences of mites provide novel tools for mite control and the development of new biomaterial with applications in biomedicine. Despite the palpable disease burden, mites remain understudied in parasitological research. By better understanding mite biology and disease processes, researchers can identify new ways to diagnose, manage, and prevent common mite-induced afflictions. This knowledge can lead to improved clinical outcomes and reduced disease burden from these remarkably widespread yet understudied creatures. [ABSTRACT FROM AUTHOR]

Varroa destructor Anderson & Trueman (Acari: Varroidae) is of paramount significance in modern beekeeping, with infestations presenting a primary challenge that directly influences colony health, productivity, and overall apicultural sustainability. In order to control this mite, many beekeepers rely on a limited number of approved synthetic acaricides, including the pyrethroids tau-fluvalinate, flumethrin and organophosphate coumaphos. However, the excessive use of these substances has led to the widespread development of resistance in various beekeeping areas globally. In the present study, the occurrence of resistance mutations in the voltage-gated sodium channel (VGSC) and acetylcholinesterase (AChE), the target-site of pyrethroids and coumaphos, respectively, was examined in Varroa populations collected throughout the southeastern and eastern Anatolia regions of Türkiye. All Varroa samples belonged to the Korean haplotype, and a very low genetic distance was observed based on cytochrome c oxidase subunit I (COI) gene sequences. No amino acid substitutions were determined at the key residues of AChE. On the other hand, three amino acid substitutions, (L925V/I/M), previously associated with pyrethroid resistance, were identified in nearly 80% of the Turkish populations. Importantly, L925M, the dominant mutation in the USA, was detected in Turkish Varroa populations for the first time. To gain a more comprehensive perspective, we conducted a systematic analysis of the distribution of pyrethroid resistance mutations across Europe, based on the previously reported data. Varroa populations from Mediterranean countries such as Türkiye, Spain, and Greece exhibited the highest frequency of resistance mutation. Revealing the occurrence and geographical distribution of pyrethroid resistance mutations in V. destructor populations across the country will enhance the development of more efficient strategies for mite management. [ABSTRACT FROM AUTHOR]

The presence of the Varroa destructor mite requires the use of acaricide treatments for honeybee colonies. Amitraz is one of the most common acaricide-active ingredients used by beekeepers. Certain Varroa mite populations have developed resistance to amitraz, thereby leading to a loss in the efficacy of amitraz-based treatments. Two products, Apivar and Supatraz, were applied in the same apiary in France to evaluate their efficacy. Both treatments are amitraz-based but have different galenics. Thanks to field data, a dynamic model was used to simulate the actions of Apivar and Supatraz on the mite population. We considered two parameters to compare the products as follows: the daily mortality rate and the treatment duration. In the field, the percentage of the efficacy of the two products was not significantly different, but Supatraz kills mites faster and decreases 90% of the mite infestation in 28.4 days compared with 50.9 days when using Apivar. Through modeling, we showed the daily impact of the two different products on mite population. Supatraz has a higher daily mortality rate during the first two weeks than Apivar. Supatraz requires a lower efficacy (% of varroa mites killed during all the treatment) to stabilize the varroa mite population due to its faster release of active ingredients than Apivar, thereby needing a shorter period to achieve the same result. Depending on the model, Supatraz conserves effective efficacy when used against moderately resistant mites (with mite mortality being 40–70% at the LC90) but not against highly resistant mites (with mite mortality being <40% at the LC90). These results show that the comparison of the efficacy of the two products with different characteristics (duration of treatment and daily mortality rate) should be analyzed with caution. [ABSTRACT FROM AUTHOR]

The two-spotted spider mite, Tetranychus urticae Koch, is one of the most important agricultural pests worldwide, with chemical application being the primary control method. However, frequent heavy use or misuse of insecticides has accelerated the development of varying degrees of resistance in T. urticae. This makes the chemical control of this mite more challenging. Biocontrol methods have attracted much attention due to their safety and environment-friendly impact. Based on previous observations that the population of T. urticae was infected by unknown pathogenic fungi, we isolated, identified, and evaluated the pathogenicity of the fungi from infected mites. Through available morphological and molecular identification, the fungus was identified as Pseudozyma flocculosa. The virulence activity of the strain was evaluated at different concentrations of spore suspension (106–109 conidia/mL) using a spraying method. The strain showed pathogenic activity against the T. urticae in adult females that varied with different concentrations and temperatures. Meanwhile, the P. flocculosa also had a significant toxic effect on the developmental stages of T. urticae. In the laboratory bioassay, the mortality rate of the tested mites reached 100% at 9 d after P. flocculosa treatment. Additionally, a wettable powder processed with P. flocculosa conidia was applied on the T. urticae in the greenhouse and the control efficacy reached up to 90% at 7 d after treatment. The results showed a high insecticidal activity of P. flocculosa against T. urticae, indicating that this fungus possesses great potential for use as a bio-insecticidal agent. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Kirkuk University for Agricultural Sciences is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) 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.)

Since the 1930s, the dry-cured ham industry has used methyl bromide fumigation to control Tyrophagus putrescentiae (ham mite) infestations. However, due to methyl bromide being a class I ozone depleting substance and no longer being manufactured, alternatives to methyl bromide have been studied extensively. Direct contact food-grade coatings and coated ham nets of various materials have shown efficacy in controlling ham mite growth and reproduction. These coated nets, often including propylene glycol, can be dried to ease application and reduce shipping cost, but chemical and thermal treatments on fabrics may cause the fabrics to become more brittle, which negatively impacts stretchability and bursting strength, and ultimately the effectiveness of the net. Scanning electron microscopy can provide precise visual inspection of fabric surface morphology, allowing for a detection of potential damage to the fibers. This purpose of this review is to summarize the application of food-grade coatings on nets used in the dry-cured ham industry to control mite infestations. More importantly, the review provides comprehensive information on coated nets, covering various aspects such as the selection of netting materials, evaluation of fabric properties, techniques for coating nets, net drying method, all in relation to their efficacy for mite control. This review contributes to the broad area of this applied technology by highlighting efficacious treatments to control mites, ineffective treatments, a discussion of processes to evaluate their properties, and future prospectives regarding this area of study. [ABSTRACT FROM AUTHOR]

Simple Summary: The aim of the study was to evaluate the viral load in honey bee colonies after adopting two brood interruption techniques that are used to control varroa mite. We evaluated the efficacy of two integrated pest management (IPM) strategies, "Queen Caging" (QC) and "Trapping Comb" (TC) procedures, in conjunction with an oxalic acid treatment, to control varroa infestations and consequently lower the viral loads of Deformed Wing Virus (DWV) and Acute Bee Paralysis Virus (ABPV). Two distinct apiaries in Slovenia and Italy, each with a different climate, served as the research sites. In the experiment, the adult bee viral load, mite fall, colony strength, and acaricide efficiency were assessed. The study indicated that the TC approach might be more successful in lowering viral loads. Our results also showed that the acaricidal efficacy of the applied IPM protocols is high. Our study is the first attempt to assess viral infections in honey bees after IPM adoption. The results show the potential advantages of using targeted varroa treatments in combination with brood interruption strategies to manage honey bee viruses vectored by varroa mite. Honey bee viruses in combination with varroa mite are very damaging for honey bee colonies worldwide. There are no effective methods to control the viral load in honey bee colonies except regular and effective control of mites. Integrated Pest Management strategies are required to effectively control mites with veterinary medicines based on organic compounds. We evaluated the effect of two brood interruption techniques, queen caging (QC) and trapping comb (TC), followed by an oxalic acid treatment, on the mite fall, colony strength, and viral load of Deformed Wing Virus (DWV) and Acute Bee Paralysis Virus (ABPV). In this paper, we report the data obtained in two experimental sites, in Slovenia and Italy, in terms of the varroacide efficacy, colony strength, and viral load. The number of adult bees after the adoption of the two techniques showed similar decreasing trends in both locations. The viral load of Acute Bee Paralysis Virus did not show any significant reduction after 25 days, reported as the number of Real-Time PCR cycles needed to detect the virus. The viral load of DWV also did not show a significant reduction after 25 days. The acaricidal efficacy of the applied protocols was high in both experimental groups and in both apiaries. Both the queen caging and trapping comb techniques, followed by an oxalic acid treatment, can be considered effective varroa treatment strategies, but further studies should be carried out to evaluate the long-term effects on viral loads to plan the Integrated Pest Management strategy with the right timing before wintering. [ABSTRACT FROM AUTHOR]

BACKGROUND: Tetranychus urticae is a hard‐to‐control pest of greenhouse strawberry production. Nighttime ultraviolet B (UV‐B) radiation using light reflection sheets (LRS) has been applied as a physical method to control T. urticae through direct ovicidal effects (the UV method). However, because strawberry leaves grow more densely, UV‐B radiation fails to reach the lower leaf surfaces inhabited by spider mites; therefore, a complementary method is required. We propose the supplemental application of phytoseiid mites in greenhouse strawberry production. We evaluated the control effects of UV‐B irradiation, phytoseiid mite application and their combined use. The effects of UV‐B irradiation on the degree of overlap relative to the independent distributions (ω) between predators and prey were also analyzed. RESULTS: The UV method alone maintained low T. urticae density levels from November to February; however, mite populations increased from March onward. Phytoseiid mite application in January and February without UV‐B irradiation resulted in a temporary increase in spider mites in March and/or April. By contrast, combined application of the UV method and phytoseiid mites had a greater control effect during the strawberry growing season. The ω values were higher for the UV method compared with no UV‐B irradiation, suggesting that UV‐B irradiation increased phytoseiid mite foraging rates. CONCLUSION: The release of phytoseiid mites compensated for the shortcomings of the UV method, and UV‐B irradiation promoted predation by phytoseiid mites by increasing the behavioral numerical response. Consequently, combined application of UV‐B irradiation and phytoseiid mites is optimal for T. urticae control in greenhouse strawberry production. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: To discover and develop novel acaricidal compounds, a series of 2‐fluoro‐4‐methyl/chlorine‐5‐((2,2,2‐trifluoroethyl)thio)aniline/phenol compounds containing N/O‐benzyl moieties were synthesized based on lead compound LZ‐1. RESULTS: The activity of these compounds against carmine spider mites (Tetranychus cinnabarinus) was determined using the leaf‐spray method. Bioassays indicated that most of the designed target compounds possessed moderate to excellent acaricidal activity against adult T. cinnabarinus. The median lethal concentrations of 25b and 26b were 0.683 and 2.448 mg L−1 against adult mites, respectively; exceeding those of bifenazate (7.519 mg L−1) and lead compound LZ‐1(3.658 mg L−1). Compound 25b exhibited 100% mortality in T. cinnabarinus larvae at 10 mg L−1. CONCLUSION: Continuing the study of these compounds in field trials, we compared the efficacy of mite killing by compound 25b with the commercial pesticide spirodiclofen and showed that mite control achieved 95.9% and 83.0% lethality at 10 and 22 days post‐treatment. In comparison, spirodiclofen showed 92.7% lethality at 10 days and 77.2% lethality at 22 days post‐treatment at a concentration of 100 mg L−1. Results showed that 25b produced more facile and long‐lasting control against T. cinnabarinus than the commercial acaricide spirodiclofen. Density functional theory analysis and electrostatic potential calculations of various molecular substitutions suggested some useful models to achieve other highly active miticidal compounds. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The two-spotted mite, Tetranychus urticea, is one of the important pests that affect strawberry plants in Iraq and continues to be present on them during most days of the year and affects the quantity and quality of the fruits produced. A study of the efficiency of treatments in T. urticae eggs showed that the treatment Betaloma+Vertimec was more efficient than the treatment Betaloma+Ortus with a percentage of 73.1 and 67.4%, respectively, and the percentage of the two treatments Merchant+Vertimec and Merchent+Ortus was 73.7 and 67.7%, respectively. As for the moving stages, the treatment of Betaloma+Vertimec and Merchent+Vertimec had the strongest effect than the treatment of Betaloma+Ortus and Merchent+Ortus, reaching 84.4, 87.9, 81.4, 81.7%, respectively. While the treatment of adults proved that the two treatments Betaloma+Vertimet and Merchent+Vertimec are the most efficient as they amounted to 82.9, 83.5%, respectively, and the treatments Betaloma+Ortus and Merchent+Ortus reached 81.6, 81.7%, respectively. It was observed from the study that the use of Vertimec on strawberry Mergent and Petaloma cultivars reduced the percentage of economic loss of strawberry plants infected with two-spotted mite, with a significant difference from Ortus, which amounted to 6.5 and 7.3%, respectively. [ABSTRACT FROM AUTHOR]

This study aimed to determine the random role of some acaricides, which are the most commonly used in Egypt for controlling Varroa destructor on Hypopharyngeal Glands (HPGs) of honey bees (Apis mellifera L.). The acaricides used in this study were Varroakiller®, Menthocaros®, Amitraz®, Varroby®, and formic acid. Results showed that the total number of fallen mites was 53.5, 47, 28.6, 26, and 24.5 for Varroakiller®, Menthocaros®, Amitraz®, Varroby®, and formic acid, respectively, compared to 16 mites in the control group. For sealed worker brood areas (SWBA), the treatments included Varroakiller® (327.98 cm2), formic acid (228.92 cm2), Varroby® (222.25 cm2), Menthocaros® (129.72 cm2), and Amitraz® (101.73 cm2), while the SWBA for control colonies was 44.83 cm2. Histological studies of the HPGs showed that although Varroakiller® effectively controlled Varroa mites and had no direct impact on worker bees or egg-laying areas, it considerably impacted the HPGs, which could ultimately affect the bee colony. Moreover, formic acid recorded a lower number of fallen Varroa with acceptable outcomes for egg-laying areas and sealed workers. This, coupled with the fact that formic acid was deemed the most significant due to its effectiveness over a short period, resulted in a reduction of 100% after 24 days. [ABSTRACT FROM AUTHOR]

Cyclamen mite is a nearly global pest of strawberry, inhabiting concealed spaces within folded leaves and flower buds emerging from plant crowns. It feeds on new plant tissue causing leaf discoloration and deformation, stunted plants, fruit bronzing and cracking, and yield losses at high population levels. Because ultraviolet-C (UV-C) irradiation is a promising new tool for disease and pest management in strawberry, and because there are few control options for cyclamen mite, we tested the direct, short-term effects of UV-C on cyclamen mite populations in potted strawberry plants in a controlled environment. Results from three experiments showed few differences in cyclamen mite populations on controls versus plants treated with UV-C (0.237 W m−1) for 3 or 4 weeks. In the second experiment, using a different strawberry cultivar and directing the UV-C from above the plant crown only, there was indication of a mild effect that may be due to some direct mortality and/or indirectly to plant defenses. However, longer-term studies will need to be conducted to determine whether pre-infestation exposure to UV-C can enable strawberry plants to better resist or tolerate cyclamen mite populations. Direct mortality did not occur as in previous experiments with pests, like twospotted spider mite, that live primarily on opened leaves. [ABSTRACT FROM AUTHOR]

Aleuroglyphus ovatus (Acari: Acaridae) is a major pest mite of stored grains that is distributed worldwide. Paeonol, a phenolic component of the essential oil extracted from the Chinese herb Paeonia moutan, possesses a range of biological activities, including antiviral, antifungal and acaricidal activity. This study investigated the bioactivity of paeonol against A. ovatus and its effect on the activity of detoxification enzymes. The bioactivity of paeonol against A. ovatus was determined by contact, fumigation and repellency bioassays, and the mechanism was preliminarily explored via morphological observation of the color changes of mite epidermis and determination of the changing trend of some important enzymes associated with acaricidal efficacy in the mites. The results showed that the median lethal concentration (LC50) in the contact and fumigation bioassays was 9.832 μg/cm2 and 14.827 μg/cm3, respectively, and the acaricidal activity of paeonol was higher under direct contact than under fumigation. Dynamic symptomatology studies registered typical neurotoxicity symptoms including excitation, convulsion and paralysis in A. ovatus treated with paeonol. The enzyme activity of catalase (CAT), nitric oxide synthase (NOS) and glutathione-S-transferase (GST) was higher, whereas the activity of superoxide dismutase (SOD) and acetylcholinesterase (AChE) was lower, compared to the control group. CAT, NOS and GST were activated, whereas SOD and AChE activities were inhibited after paeonol intervention. Our findings suggest paeonol has potent acaricidal activity against A. ovatus and thus may be used as an agent to control the stored-product mite A. ovatus. [ABSTRACT FROM AUTHOR]

BACKGROUND: The tomato russet mite, Aculops lycopersici, is a major pest in tomato crops, causing damage through leaf and stem browning, defoliation and russeting of fruit. Biological control of this mite on tomato plants is difficult. While several phytoseiid mites feed on the pest, they cannot survive, move, or reproduce on tomato plants due to the presence of glandular trichomes. Pronematus ubiquitus has recently been identified as a biocontrol agent of A. lycopersici in tomato crops, but the predator–prey interaction between these two species is not well studied. In this paper, we present a validated logistic regression predator–prey model based on a 3‐year study supplemented with additional datasets. Besides the predator and the prey, this model takes into account an extra generalist predator, Macrolophus pygmaeus, and various climate parameters. RESULTS: The population trend of A. lycopersici is best explained by the presence of the predator P. ubiquitus, the relative humidity and the fact that the crop was lit or unlit using artificial light. P. ubiquitus has proved to be an efficient biocontrol agent of A. lycopersici. For P. ubiquitus the presence of M. pygmaeus, the vapour pressure deficit, the number of light hours and radiation explained the population trend best. For both the predator and the prey density‐dependent interactions were identified. Model outcomes are discussed in detail. CONCLUSION: Our study provides insights into the potential use of P. ubiquitus as a biocontrol agent for A. lycopersici in tomato crops in combination with M. pygmaeus. However, we highlight the importance of considering the presence of other predators and environmental conditions when developing integrated pest management strategies. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Olive (Olea europaea L.) is a subtropical tree cultivated in arid, dry and temperate regions. Olive orchards in Al‐Jouf of Saudi Arabia are the largest worldwide and currently face harmful pest infestation. The present study aimed at evaluating the efficiency of the predatory mite Agistemus exsertus Gonzalez (Acari: Stigmaeidae) and the exogenously applied melatonin (MT), glycine betaine (GB) and 5‐aminolevulinic acid (ALA) as eco‐friendly approaches for enhancing the biological control of four mite species (Tegolophus hassani, Oxycenus niloticus, Aceria olivi and Tetranychus urticae) infesting olive trees in Al‐Jouf under laboratory and field conditions. Field experiment was conducted on 6‐year‐old Manzanillo olive trees grown in a private orchard farm in Al‐Jouf during two seasons, 2020 and 2021. Results revealed that A. exsertus developed successfully from egg to adult. The females of T. hassani, O. niloticus, A. olivi, and T. urticae required 7.36, 8.89, 9.98 and 8.38 days, respectively, to develop from egg to adult at 28°C and 65 ± 5% relative humidity. O. niloticus was the most preferred prey of A. exsertus. The net reproductive rate (R0) was 42.1, 38.7, 34.6 and 36.8 females/female/generation, the intrinsic rate of increase (rm) was 0.27, 0.26, 0.23 and 0.20 females/female/day, and the mean generation time (T) was 16.2, 17.1, 18.6 and 17.2 days when a predator consumed T. hassani, O. niloticus, A. olivi and T. urticae, respectively. The adult female consumed daily about 114 O. niloticus, 105 A. olivi, 95 T. hassani and 15.2 T. urticae individuals, respectively. A. exsertus proved to be an effective biocontrol agent against mites infesting olive trees. In addition, the exogenous application of 1 mM MT, 15 mM GB and 25 mg/L ALA, alone or in combination, caused significant mortality for the four mites. Application of these natural compounds, alone or in combination, also significantly enhanced the growth, relative water content, relative chlorophyll, content of flavonoid and nutrients, antioxidant enzymes activities, stress‐related genes expression and fruit yield and quality of the infested olive trees compared to non‐treated infested trees. This study is the first that demonstrates the efficiency of these eco‐friendly approaches for controlling mites infesting olive trees, and could be used as a replacement for the harmful chemical acaricides. [ABSTRACT FROM AUTHOR]

Cyetpyrafen is a compound that lacks inherent uptake and systemic translocation activity. If mites do not come into direct contact with the pesticide solution on leaves, the efficacy cannot be achieved. Controlling the particle size can potentially play a crucial role in the manifestation of efficacy. In this study, high-throughput formulation technology was used to systematically screen a large number of adjuvants to obtain cyetpyrafen formulations. The particle size of the active ingredient in the formulation was measured. By examining the dynamic light scattering and contact angle, we simulated the actual process of the efficacy transmission of cyetpyrafen formulations against Tetranychus cinnabarinus. Our results showed that the activity of cyetpyrafen increases as the particle size decreases, suggesting that reducing the particle size can enhance the coverage and deposition on crop leaves, and further improve the dispersion efficiency and enhance spreading capabilities. Furthermore, controlling the particle size at 160 nm resulted in an LC50 value of 0.2026, which is approximately double than that of the commercial product. As a novel pesticide for mites, our study presents the most effective cyetpyrafen formulation in practice. Our findings provide valuable insights into controlling other mite species that pose a threat to agricultural products. [ABSTRACT FROM AUTHOR]

Different plant part extracts of cherry laurel [Prunus laurocerasus (Rosaceae)] were investigated for the acaricidal and repellent activity against Polyphagotarsonemus latus (Prostigmata: Tarsonemidae). The leaf, flower, and seed aqueous extracts of cherry laurel were prepared for efficacy bioassays. The tested concentrations of each extract were 1% (volume/volume, v/v), 5% (v/v), 10% (v/v), 20% (v/v) and 30% (weight/volume, w/v). Distilled water and a mixed formulation of 228.6 g/L spiromesifen + 11.4 g/L abamectin were used as negative and positive controls, respectively. It can be concluded that the flower and leaf extract of P. laurocerasus at 30% concentration and the seed extract at 10% or greater concentrations have the potential to control P. latus in the egg stage. Although spiromesifen+abamectin caused extremely low egg mortality (9.5%), all larvae died shortly after hatching (indirect ovicidal effect). In contrast, all adult mites died within 20 hours after spraying. Moreover, the adult mortalities (92%-98%) associated with seed extract at 30% during the experimental period, and the leaf (93.78%) and flower (91.11%) extract at 30% 72-h after exposure were statistically similar to that of spiromesifen+abamectin (100%) application. All extracts at 20% and seed extract at 10% or greater concentrations may also have a great potential for repelling P. latus. [ABSTRACT FROM AUTHOR]

Mites have been a persistent infectious disease affecting both humans and animals since ancient times. In veterinary clinics, the primary approach for treating and managing mite infestations has long been the use of chemical acaricides. However, the widespread use of these chemicals has resulted in significant problems, including drug resistance, drug residues, and environmental pollution, limiting their effectiveness. To address these challenges, researchers have shifted their focus towards natural products that have shown promise both in the laboratory and real-world settings against mite infestations. Natural products have a wide variety of chemical structures and biological activities, including acaricidal properties. This article offers a comprehensive review of the acaricidal capabilities and mechanisms of action of natural products like plant extracts, natural compounds, algae, and microbial metabolites against common animal mites. [ABSTRACT FROM AUTHOR]

Despite being an ectoparasite of birds, Dermanyssus gallinae (D. gallinae) has no specific host range. Without a natural host, the mite can feed on mammals, including humans, due to its lack of specificity. As a result of red mite infestations, poultry industry economies have been negatively affected, egg production has declined, and chickens' welfare has been compromised. Several in vitro studies have demonstrated the effectiveness of diesel, petroleum, mineral, and plant oils (orange and rapeseed) in controlling poultry red mites. It is possible to develop vaccines against arthropods; however, this process takes a long time due to its complexity and the possibility of inducing stronger and longer-lasting immune responses in the host. This review paper aimed to comprehensively understand the morphology, the factors contributing to red mite infestation, and the life cycle. It also provides an overview of various methods for preventing and controlling the infestation of red mites in poultry farming, including several chemical and non-chemical approaches that can be used. Chemical interventions, such as acaricides, exhibit immediate efficacy in red mite control, but their long-term sustainability and potential resistance development are significant concerns. Non-chemical methods, including enhanced biosecurity measures and natural predators, demonstrate promise in reducing red mite populations, offering environmentally friendly alternatives with potential long-term benefits. In order to minimize the negative impact of red mites on poultry flocks, poultry producers must understand the biology of these parasites and implement effective management strategies. [ABSTRACT FROM AUTHOR]

[Display omitted] • Varroa reproductive success was reduced in three mite-resistant honey bee populations. • Host brood traits reduce mite reproduction, independent of adult bees. • The added presence of adult bees did not increase the rate of reduced mite reproduction. • Fundamental understanding of the host brood–parasite relationship is required for future work. The ectoparasitic mite Varroa destructor is an invasive species of Western honey bees (Apis mellifera) and the largest pathogenic threat to their health world-wide. Its successful invasion and expansion is related to its ability to exploit the worker brood for reproduction, which results in an exponential population growth rate in the new host. With invasion of the mite, wild honeybee populations have been nearly eradicated from Europe and North America, and the survival of managed honeybee populations relies on mite population control treatments. However, there are a few documented honeybee populations surviving extended periods without control treatments due to adapted host traits that directly impact Varroa mite fitness. The aim of this study was to investigate if Varroa mite reproductive success was affected by traits of adult bee behaviours or by traits of the worker brood, in three mite-resistant honey bee populations from Sweden, France and Norway. The mite's reproductive success was measured and compared in broods that were either exposed to, or excluded from, adult bee access. Mite-resistant bee populations were also compared with a local mite-susceptible population, as a control group. Our results show that mite reproductive success rates and mite fecundity in the three mite-resistant populations were significantly different from the control population, with the French and Swedish populations having significantly lower reproductive rates than the Norwegian population. When comparing mite reproduction in exposed or excluded brood treatments, no differences were observed, regardless of population. This result clearly demonstrates that Varroa mite reproductive success can be suppressed by traits of the brood, independent of adult worker bees. [ABSTRACT FROM AUTHOR]

The Varroa mite is one of the most important pests of honey bee colonies. This study compares the efficiency of thymol-based acaricides with the tau-fluvalinate-based commercial treatment to control this mite species. Two experiments were conducted: (1) in the Fall, thymol-based gel was compared with a widely used acaricide, fluvalinate-impregnated strips (Apistan®), and (2) in the Spring, gels containing thymol-only, thymol + menthol + eucalyptus essential oil, and thymol + thyme essential oil were compared with fluvalinate-impregnated strips. In the first experiment, both treatments reduced Varroa mite infestation levels significantly after 70 days of their application compared to the control treatment. The results of the second experiment showed that thymol + thyme essential oil gel, thymol + menthol + eucalyptus essential oil gel, and Apistan strips had always higher efficiency on decreasing mite infestation levels of the selected colonies compared to the control treatment and thymol-only gel during their 7-week application. The results of this study demonstrate that plant-based acaricides for controlling Varroa mites in honey bee colonies have similar efficiency compared to the chemical control methods. Therefore, it is better to use these selected acaricides to reduce mite resistance to chemical control treatments in honey bee colonies. [ABSTRACT FROM AUTHOR]

BACKGROUND: Panonychus citri is a globally dominant citrus plant pest mite. Pesticide‐induced population resurgence is a concern for mite control. Exposure to sublethal concentrations of pesticides has stimulated reproduction and outbreak risks in many pests. Pyridaben, a mitochondrial electron transport inhibitor, has been frequently used worldwide in mite control. In the study, sublethal and transgenerational effects of pyridaben exposure on Pyr_Rs (resistant) and Pyr_Control (susceptible) strains were systematically investigated in both exposed parental generation (F0) and unexposed offspring generations (F1 and F2) by evaluating life‐table and physiological parameters. RESULTS: After exposure to pyridaben, the fecundity of both strains was significantly reduced in F0 generation while significantly induced in F1 generation. Interestingly, these effects also stimulated the fecundity of the F2 generation in Pyr_Control strain while no significant effects occurred for Pyr_Rs strain. The intrinsic rate of increase (r) and finite rate of increase (λ) were significantly decreased only in F1 generation of Pyr_Control strain after exposure treatment. Meanwhile, the population projection indicated a smaller population size in F1 generation of Pyr_Control strain while a population increase for Pyr_Rs strain after sublethal treatment. Subsequent detoxification enzyme assays indicated that only P450 activities in F0 generation were significantly activated by LC30 exposure to pyridaben in both strains. Significant downregulation of reproduction‐related (Pc_Vg) genes was observed in the F0 generations of both strains. Significant upregulation of P450 (CYP4CL2) and Pc_Vg of the F1 generation in both strains suggested the presence of delayed hormesis effects on the reproduction and developed tolerance to pyridaben, although the effects did not last over a longer period (F2 generation). CONCLUSION: These results provide evidence for transgenerational hormesis effects of low concentrations of pyridaben exposure that may lead to population increase and resurgence risks of resistant‐mites in natural settings by stimulating reproduction. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: Amitraz is a broad‐spectrum formamidine acaricide proven to be effective against mites in all development stages. Under acidic conditions, amitraz is hydrolyzed to N2‐(2,4‐dimethylphenyl)‐N1‐methyformamidine (DPMF), an active metabolite for mite control. Octopamine and tyramine receptors are well known targets of amitraz. Until now, no research has been conducted about the amitraz target in Tetranychus cinnabarinus. This study aimed to identify the target genes of amitraz in T. cinnabarinus and reveal the mechanisms behind the differential acaricidal activities of amitraz and DPMF. RESULTS: Analysis of the toxicity, stress expression, target sensitivity and binding site of amitraz against T. cinnabarinus showed that TcOctβ2R was the main target gene of amitraz. DPMF had more potent acaricidal activity against T. cinnabarinus and was more effective at activating TcOctβ2R than amitraz. Furthermore, the three synergists had no significant effect on amitraz and DPMF, indicating that the detoxification metabolism was not related to the difference in acaricidal activity. CONCLUSION: In this study, TcOctβ2R was identified as the main target gene of amitraz against T. cinnabarinus. The divergence of target binding was responsible for the difference in acaricidal activity between amitraz and DPMF. The results also revealed the physiological and pharmacological functions of octopamine receptors (OARs) in T. cinnabarinus and could provide a basis for the design of new acaricides, with OARs as a special target. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

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This publication is designed to provide information on managing spider mites on hops grown in Florida to hops growers, UF/IFAS Extension agents, and other crop protection professionals. Hops (Humulus lupulus L.) (Cannabinaceae), a new crop for Florida, has been studied at the UF/IFAS Gulf Coast Research and Education Center (GCREC) since 2016. A fall and spring crop have been cultivated each year, providing opportunity to observe pests and evaluate pest management strategies over several seasons. Spider mites (Trombidiformes: Tetranychidae) have been a consistent pest of hops at GCREC each season. Information on chemical and biological control is provided.

Beekeepers can use a variety of treatments against Varroa destructor, the parasitic mite of Apis mellifera. However, sustainable and easy-to-use solutions are still scarce, considering the complexity of reaching the parasite alone. Current treatments involve soft acaricides, although their mechanism of action is not well understood. We investigated the effects of organic acids such as tartaric, lactic, formic, and citric acids on the attachment abilities of V. destructor under laboratory conditions. Preventing parasites from gripping or holding on to their hosts is a crucial target for mite control strategies. We challenged grip skills through the Rotavar setup after the direct application of acids to mites' arolia. We also tested the potential for mites to fall off honeybees after bee treatment. We found that tartaric, citric, and lactic acids were good candidates to impair the attachment of V. destructor twenty-four hours post-treatment. However, lactic acid remained the only candidate at a reasonable concentration to destabilise mites after the honey bee's treatment without reducing their lifespan. While we conducted these experiments under artificial conditions, our results improved our comprehension of the organic acids' potential impact on V. destructor. They can also help with the development of new methods for hive application for beekeepers worldwide. [ABSTRACT FROM AUTHOR]

Panonychus citri (McGregor) is one of the most destructive pests of citrus trees. Its control is difficult because it has developed resistance to some synthetic pesticides. GC-mite is a novel botanical pesticide based on cottonseed, clove, and garlic oils that has shown the potential to control tetranychid mites. This study aimed to evaluate the effects of sublethal concentrations of GC-mite on the life history and biochemical parameters of P. citri. Age-stage life table procedure was used to evaluate the effects of two sublethal concentrations (LC20 = 59.40 μg ml−1 and LC30 = 78.66 μg ml−1) of GC-mite on the development, longevity, and reproduction of P. citri. The biochemical analysis included the content of lipids, carbohydrates and glycogen, esterase, and glutathione S-transferase (GST) activities. The developmental time of treated mites with LC30 was significantly longer than the control but the adult longevity and oviposition days of P. citri treated with both sublethal concentrations decreased. The total fecundity of treated mites decreased with increasing GC-mite concentration applied. The life table analysis showed that sublethal concentrations of GC-mite significantly affected gross reproductive rate (GRR), net reproductive rate (R0), intrinsic rate of increase (r), and mean generation time (T). The estimated values of r were significantly lower than the control in LC20 (0.130 day−1) and LC30 (0.117 day−1). The lipids, carbohydrates and glycogen contents as well as esterase and GST activities were significantly lower in mites treated with LC30 concentration, but no significant effect was found in mites treated with LC20 and control. These results suggest that sublethal concentrations of GC-mite had significant effects on both demographic and biochemical parameters of P. citri. [ABSTRACT FROM AUTHOR]

The predatory mite Neoseiulus californicus (McGregor) (Acari: Phytoseiidae) is a key natural enemy applied in phytophagous mite control in agricultural production areas. This study is aimed at investigating the development of pyridaben resistance as a result of the selection pressure under laboratory conditions on N. californicus mites, the inheritance of pyridaben resistance in this predatory mite, and the relationship of resistance with target region mutations. Pyridaben resistance levels were evaluated using a leaf disc spraying tower method. As a result of seven selections, 270-fold pyridaben resistance was identified in N. californicus. As a result of inheritance studies, pyridaben resistance in F1 females resulted from incomplete dominance and sex. Neoseiulus californicus was resistant to pyridaben and there was no significant difference in the monooxygenase enzyme levels in respect to the initial population. No amino acid changes were detected in the PCR evaluations of target site mutations in the pyridaben-resistant and initial populations of N. californicus. Increased pyridaben resistance in the selected population was thought to be caused by more mechanisms other than target site mutations. [ABSTRACT FROM AUTHOR]

Amblyseius orientalis (Ehara) (Acari: Phytoseiidae) is an effective predatory mite for spider mite control on fruit trees in China. In recent decades, it has been produced massively at a commercial natural enemy producer, feeding on the storage mite Carpoglyphus lactis (L.). In the predator production process, the ratio of predatory mites to their prey was found to be critical for the population increase of A. orientalis in large-scale rearings. In this study, we investigated the predatory capacity of A. orientalis on various developmental stages of the prey C. lactis, and the effect of prey numbers on predator reproduction. The maximum predation rate of A. orientalis adults on C. lactis adults was 2.21 per day at the lowest density of five prey adults, and on C. lactis eggs it was 45.07 at the highest density of 60 prey eggs. The preference index Ci of A. orientalis on C. lactis eggs and adults was 0.4312 and − 0.9249, respectively, suggesting that A. orientalis preferred eggs to adults. Amblyseius orientalis could reproduce when it preyed on either eggs or deutonymphs of C. lactis. However, the fecundity of the predatory mites is not always proportional to the provided prey number. Higher density of prey deutonymphs resulted in lower fecundity, whereas more prey eggs resulted in higher fecundity of A. orientalis. Therefore, our study indicated that the choice of suitable density and developmental stage of prey can significantly improve A. orientalis production on a large scale. [ABSTRACT FROM AUTHOR]

The two-spotted spider mite, Tetranychus urticae Koch, has a broad host plant range and presents an extreme capacity for developing pesticide resistance, becoming a major economic pest in agriculture. Anticholinesterase insecticides still account for a big part of global insecticide sales. However, there is a growing concern about the serious resistance problems of anticholinesterase insecticides and their nontarget toxicity. In this study, structure-based virtual screening was performed to discover selective AChE inhibitors from the ChemBridge database, and 39 potential species-specific AChE inhibitor were obtained targeting T. urticae AChE, but not human AChE. Among them, compound No. 8 inhibited AChE from T. urticae , but not from human, and had an inhibitory activity comparable to that of eserine. Compound No. 8 had dose-dependent toxicity to T. urticae in glass slide-dipping assay and had significant mite control effects in a pot experiment, but required a high concentration to achieve similar control effects to spirodiclofen. The toxicity evaluation suggested that compound No. 8 had no acute toxicity on pollinator honey bees and natural predator N. californicus and did not affect strawberry growth in our assay. Compound No. 8 is a potential lead compound for developing novel acaricides with reduced nontarget toxicity. [ABSTRACT FROM AUTHOR]

Tetranychus urticae is a worldwide common pest for many vegetable species in greenhouses and open fields. The study was conducted to evaluate the performance of two acaricide mixtures: Highpoint® 10% EC (abamectine + hexythiazox) and Ignar® 20% SC (abamectine + spirodiclofen), as well as a single active ingredient, Envidor® 24% SC (spirodiclofen), against the two-spotted spider mite in greenhouse and lab experiments. In the greenhouse experiment, both Ignar® and Highpoint® outperformed Envidor® acaricide against the adult and immature stages through the first 3 days in both experimental seasons. After 24 hours, Ignar® and Highpoint® achieved the highest efficacy with percent of reduction 95.00 and 94.86 in the 1st season and 97.84 and 95.76% in the 2 nd season, respectively. Meanwhile, Envidor® gave lower reduction percentages of 84.93 and 83.88%, respectively. Regarding the immature stage, Ignar®, Highpoint®, and Envidor® achieved reductions of 95.63%, 94.26%, and 83.31% after 24 hours for the first season and 94.09, 95.79, and 80.57% in the second season, respectively. The residual efficacy gradually decreased to reach 62.22 and 59.72% for Ignar® and 58.31 and 59.31% for Highpoint® in both seasons. On the other hand, the initial kill for all acaricides against the egg stage was low after 24 hours. However, after 3 days, Ignar® and Highpoint® showed a sharp increase in efficacy, with a reduction percent (81.24 and 51.60% in the 1st season) and (73.83 and 81.86% in the 2nd season), respectively. Envidor® showed high efficacy only at the 7th day, with varying efficacy during the inspection periods. Laboratory bioassay tests revealed that Ignar® was the most toxic acaricide against T. urticae adults and immatures, with a 100% toxicity index. Highpoint® had a moderate toxicity index against adult and immature stages, while Envidor® was less effective. Ignar® and Highpoint® were the most toxic compounds against eggs. Abamectin mixtures are the most toxic compounds. Highpoint® and Ignar®, were considered to have the best efficacy on all developmental stages of the two-spotted spider mite. Due to the extensive use of abamectin to eliminate mites and numerous sucking insects, it is better to avoid its repeated use alone or in the same mixtures to control mites for more than one or two applications in the season. The data may suggest that the appropriate acaricide for integrated pest management (IPM) for all stages of T. urticae could be Ignar® and Highpoint®. [ABSTRACT FROM AUTHOR]