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Purpose: The flea Ctenocephalides felis (Siphonaptera: Pulicidae), parasitizes dogs and cats globally, acting as a vector for various pathogens affecting both animals and humans. Growing interest in environmentally friendly, plant-based products prompted this study. The aim of the study was to determine the chemical composition of essential oils (EOs) from Copaifera reticulata, Citrus paradisi, Lavandula hybrida and Salvia sclarea, assessing their insecticidal and repellent properties, determining lethal concentrations (LC50 and LC90), and evaluating residual efficacy in vitro against Ctenocephalides felis felis. Methods: Gas Chromatography with Flame Ionization Detector analyzed EO composition. In vitro tests involved preparing EO solutions at various concentrations. Ten specimens from each life stage (egg, larva, pupa, adult) were used for insecticidal activity assessment. Adulticidal activity was assessed using 10 cm2 filter paper strip, each treated with 0.200 mL of the test solution. Immature stages activities were evaluated using 23.76 cm2 discs of the same filter paper, each treated with 0.470 mL of the test solution. Mortality percentage was calculated using (number of dead insects × 100) / number of incubated insects. Probit analysis calculated LC50 values with a 95% confidence interval. Results: Major EO constituents were β-caryophyllene (EOCR), linalool (EOLH), linalyl acetate (EOSS), and limonene (EOCP). LC50 values were obtained for all stages except for the essential oil of C. paradisi. All oils showed repellent activity at 800 μg/cm2. OECR exhibited greater residual efficacy. Conclusion: Each EO demonstrated superior insecticidal activity against specific C. felis felis stages. [ABSTRACT FROM AUTHOR]

Bees play an essential role in the sustainability of terrestrial and agricultural ecosystems as pollinators. However, external factors such as pesticides can negatively affect both bees and plants pollinated by bees, as well as human health. Therefore, less toxic or non-toxic plant protection products have become a popular research topic for a sustainable environment. The purpose of this study was to determine the effects of four different commercial products of diatomaceous earth (Bio, Demite, Detech, Detech WP) on workers of Apis mellifera and Bombus terrestris under controlled laboratory conditions. Each diatomaceous earth product was sprayed on the bees as dust particles for 15 seconds at Maximum Field Dose (10 g/m2). While the worker bees in positive control groups (control +) were exposed to flour, those in the negative control groups (control –) were not exposed to any treatment. The highest mortality rates for B. terrestris and A. mellifera were 22% in Detech WP and 16% in Demite, respectively. However, since mortality rates were under 25% for all the tested DE products, they were classified as harmless for both bee species. Additionally, the direct effect of diatomaceous earth products on honey bees and bumble bees was revealed for the first time in this study. [ABSTRACT FROM AUTHOR]

Copyright of Acta Biologica Slovenica is the property of Drustvo Biologov Slovenije 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.)

The insecticidal compound pyrethrin is synthesized in Dalmatian pyrethrum (Tanacetum cinerariifolium (Trevis.) Sch.Bip.; Asteraceae), a plant species endemic to the eastern Mediterranean. Pyrethrin is a mixture of six compounds, pyrethrin I and II, cinerin I and II, and jasmolin I and II. For this study we sampled 15 natural Dalmatian pyrethrum populations covering the entire natural distribution range of the species; Croatian coastal regions and the islands, inland Bosnia and Herzegovina and Montenegro. The plants were grown in a field experiment under uniform growing conditions to exclude a short-term response to environmental factors and instead observe variation in pyrethrin content and composition among and within populations due to genetic adaptation to the native environment. The drivers of local adaptation were explored by examining the role of bioclimatic factors as a cause of population differentiation. Pyrethrins were extracted by ultrasound-assisted extraction, and the extracts were analyzed by HPLC-UV-DAD. The populations differed significantly in the content and composition of pyrethrins. The highest levels of total pyrethrins (1.27% flower DW), were found in population P14 Budva and the significantly highest levels of pyrethrin I in population P14 Vranjske Njive, Podgorica (66.47% of total pyrethrin). Based on bioclimatic conditions of the sampling sites, populations were grouped into five bioclimatic groups (A, B, C, D, and E), which showed qualitative and quantitative variability in pyrethrin content. The most abundant bioclimatic group was bioclimatic group E, which was characterized by the highest average values for pyrethrin I (53.87% of total pyrethrin), total pyrethrin content (1.06% flower DW) and the ratio of pyrethrin I and II (1.85). The correlation analysis between the pyrethrin compounds and some of the bioclimatic variables (e. g., BIO03 Isothermality and BIO04 Temperature seasonality) showed their significant contribution in explaining the variation of pyrethrins in T. cinerariifolium. The differences in pyrethrin content and composition may be partly due to genetic adaptation to the ecological conditions of the native environment. The obtained data would enable the selection of source populations for breeding programs aimed at producing cultivars with desirable biochemical properties and adaptation to different bioclimatic conditions. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Protection & Pathology is the property of Egyptian National Agricultural Library (ENAL) 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: Natural insecticides are currently given high priority in Integrated Pest Management (IPM) protocols. To this end, diatomaceous earth (DE) has gained a lot of attention as an environmentally friendly alternative to conventional insecticides that can successfully repel and control a diverse variety of the most important stored-product insect pests, such as the species Sitophilus, Rhyzopertha, Tribolium, and others. However, most published research about the DEs' insecticidal efficacy has been conducted in simplistic short-term laboratory experiments, excluding the evaluation of the persistence of such ingredients in grain applications. In this study, we evaluated two different DE formulations derived from a single deposit from Greece, when applied in wheat and maize against two primary stored-product insect pests, Sitophilus oryzae (L.) (Coleoptera: Curculionidae) and Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae). Based on the results, the DE application was effective and persistent as a grain protectant against major stored-product insects for a storage period of six months. This study provides more evidence for the successful utilization of these natural insecticides for long-term protection of stored products from insect infestations, as an alternative to residual insecticides and fumigants that are commonly used in stored-grain protection systems or as part of integrated pest management (IPM) strategies. We evaluated the persistence and efficacy of two different, in granulometry and content of diatoms, diatomaceous earth (DE) formulations (i.e., DE5 and DE6), against two major beetle species of stored products, i.e., Sitophilus oryzae (L.) (Coleoptera: Curculionidae) and Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae). The formulations were applied as powders in soft wheat and maize in two doses of 500 and 1000 mg kg−1 (ppm). Samples of the treated grains were taken on the day of application and every 30 days until completion of the six-month period of storage. Adults of S. oryzae and R. dominica were exposed to the treated grains at 25 °C and 55% relative humidity, and the mortality was measured after 7, 14, and 21 days of exposure. Rhyzopertha dominica survival was not affected by any combination of DE formulation, dose, and commodity. Contrariwise, the DEs caused significant adult mortality of S. oryzae, in most of the cases tested. We observed that DE6 was equally effective in both wheat and maize, and no considerable variations were observed in S. oryzae mortality during the 6-month experimental period. Furthermore, DE6 was more effective against S. oryzae than DE5, a difference that could have potentially contributed to the variations in the diatom granulometry between these two DEs. Thus, a DE treatment of 1000 ppm was shown to provide long-term protection of wheat and maize against S. oryzae, but this is strongly dependent on the DE formulation, commodity, and insect species. Overall, such natural resource-based inert silicaceous deposits could be used with success in stored-product protection with only some minor modifications, such as sieving and drying of the raw deposit. [ABSTRACT FROM AUTHOR]

Although N,N-diethyl-3-methylbenzamide (DEET) remains the most effective repellent against mosquitoes and ticks, concerns about skin irritation, rashes, and neurological problems in children have driven the search for natural alternatives. The aim of this research was to develop, manufacture, and test prototype stickers derived from invasive plant species in Europe. These labels contained a coating with encapsulated repellents made from essential oils to protect against mosquito bites and similar blood-sucking insects. Six samples of invasive plant species in Europe such as Japanese knotweed (Fallopia japonica), goldenrod (Solidago gigantea), and black locust (Robinia pseudoacacia) were coated with two essential oil mixtures (of geranium, lavender, and eucalyptus) and were encapsulated on solid carriers for prolonged evaporation. Analysis of the structural properties (weight, thickness, density, and specific volume) were carried out on the coated label samples. Analysis of surface properties (roughness and porosity), capillary absorption, and a comparison of time and evaporation of essential oils were also carried out. Scanning electron microscopy was performed on the samples and the solid carrier with different mixtures of essential oils. The Japanese knotweed sample, coated with a blend of geranium, lavender, and eucalyptus essential oils, showed the highest efficacy and stability. [ABSTRACT FROM AUTHOR]

The insecticidal compound pyrethrin is synthesized in Dalmatian pyrethrum (Tanacetum cinerariifolium (Trevis.) Sch.Bip.; Asteraceae), a plant species endemic to the eastern Mediterranean. Pyrethrin is a mixture of six compounds, pyrethrin I and II, cinerin I and II, and jasmolin I and II. For this study we sampled 15 natural Dalmatian pyrethrum populations covering the entire natural distribution range of the species; Croatian coastal regions and the islands, inland Bosnia and Herzegovina and Montenegro. The plants were grown in a field experiment under uniform growing conditions to exclude a short-term response to environmental factors and instead observe variation in pyrethrin content and composition among and within populations due to genetic adaptation to the native environment. The drivers of local adaptation were explored by examining the role of bioclimatic factors as a cause of population differentiation. Pyrethrins were extracted by ultrasound-assisted extraction, and the extracts were analyzed by HPLC-UV-DAD. The populations differed significantly in the content and composition of pyrethrins. The highest levels of total pyrethrins (1.27% flower DW), were found in population P14 Budva and the significantly highest levels of pyrethrin I in population P14 Vranjske Njive, Podgorica (66.47% of total pyrethrin). Based on bioclimatic conditions of the sampling sites, populations were grouped into five bioclimatic groups (A, B, C, D, and E), which showed qualitative and quantitative variability in pyrethrin content. The most abundant bioclimatic group was bioclimatic group E, which was characterized by the highest average values for pyrethrin I (53.87% of total pyrethrin), total pyrethrin content (1.06% flower DW) and the ratio of pyrethrin I and II (1.85). The correlation analysis between the pyrethrin compounds and some of the bioclimatic variables (e. g., BIO03 Isothermality and BIO04 Temperature seasonality) showed their significant contribution in explaining the variation of pyrethrins in T. cinerariifolium. The differences in pyrethrin content and composition may be partly due to genetic adaptation to the ecological conditions of the native environment. The obtained data would enable the selection of source populations for breeding programs aimed at producing cultivars with desirable biochemical properties and adaptation to different bioclimatic conditions.

Introduction: The control of mosquito populations to prevent disease transmission relies profoundly on the application of larvicides. However, the surge of resistance poses a significant threat. Botanical insecticides serve as an alternative approach for vector control, and thus, this study aimed to evaluate the larvicidal capabilities of Ananas comosus flesh against Aedes albopictus. Methods: An aqueous extract of A. comosus was concentrated using the double-boiling method. The crude extract was diluted through the serial dilution technique. Mosquito eggs were collected using ovitraps and reared until adulthood under standard insectarium conditions. Late third and early fourth instar of Ae. albopictus larvae (30 larvae/replicate, n = 3) were exposed to the extract, and the mortality rate was recorded following 24 h and 48 h exposure. Results: Probit analysis revealed that the median lethal concentration, LC50 and 90% lethal concentration after 24 h were 17.24 (9.62 - 21.03) and 24.53 (19.74 - 31.13) %, respectively. The LC50 and LC90 values for 48 h were 8.45 (6.49 - 10.06) and 11.59 (9.72 - 14.81) %, respectively. Conclusion: The findings suggest that A. comosus flesh revealed activity against Ae. albopictus, making it a potential botanical-derived larvicide. Future studies should focus on investigating the phytochemicals responsible for larval mortality and their mode of action. [ABSTRACT FROM AUTHOR]

We evaluated the persistence and efficacy of two different, in granulometry and content of diatoms, diatomaceous earth (DE) formulations (i.e., DE5 and DE6), against two major beetle species of stored products, i.e., Sitophilus oryzae (L.) (Coleoptera: Curculionidae) and Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae). The formulations were applied as powders in soft wheat and maize in two doses of 500 and 1000 mg kg−1 (ppm). Samples of the treated grains were taken on the day of application and every 30 days until completion of the six-month period of storage. Adults of S. oryzae and R. dominica were exposed to the treated grains at 25 °C and 55% relative humidity, and the mortality was measured after 7, 14, and 21 days of exposure. Rhyzopertha dominica survival was not affected by any combination of DE formulation, dose, and commodity. Contrariwise, the DEs caused significant adult mortality of S. oryzae, in most of the cases tested. We observed that DE6 was equally effective in both wheat and maize, and no considerable variations were observed in S. oryzae mortality during the 6-month experimental period. Furthermore, DE6 was more effective against S. oryzae than DE5, a difference that could have potentially contributed to the variations in the diatom granulometry between these two DEs. Thus, a DE treatment of 1000 ppm was shown to provide long-term protection of wheat and maize against S. oryzae, but this is strongly dependent on the DE formulation, commodity, and insect species. Overall, such natural resource-based inert silicaceous deposits could be used with success in stored-product protection with only some minor modifications, such as sieving and drying of the raw deposit.

The insecticidal effect of two zeolite formulations was tested on wheat against adults of Lepinotus reticulatus Enderlein, Liposcelis decolor (Pearman), Acarus siro L. and Stegobium paniceum (L.). The zeolites were tested at four dose rates, i.e., 50, 100, 500 and 1000 ppm (mg per kg of wheat). The bioassays were conducted under laboratory conditions. The vials for A. siro were kept at 22°C, 60–70% relative humidity (r.h.), for psocids were kept at 30°C, 75–80% r.h., and for S. paniceum were kept at 26°C, 65–70% r.h., with continuous darkness. The bioassays were conducted in cylindrical glass vials of 20 ml (beetles and psocids) or 4 ml (mites). There were three replicates for each treatment, whereas each bioassay was repeated three times for S. paniceum and A. siro, whereas for psocids species, there were three vials for each treatment. Each vial was filled with 10 g of wheat for psocids and S. paniceum, and 2 g for A. siro. Afterward, ten adults of each species were placed in each vial, with separate series of vials per species, and all vials were kept at the aforementioned conditions. Mortality was determined after 4, 7, and 14 d of exposure for psocids, 3, 7 and 14 d of exposure for S. paniceum and 14 d of exposure for A. siro. From the species tested, L. reticulatus and S. paniceum were by far the most susceptible species, given that mortality reached 100% after 14 days of exposure. In contrast, for the other two species, mortality rate for L. decolor was 27% and for A. siro was 54% after 14 d of exposure at 1000 ppm, indicating that for these species, rapid rebound of their populations is likely to occur. The current study provides data on the toxicity of zeolites against four stored-product insect species, for which the relative data available were scarce. [ABSTRACT FROM AUTHOR]

Simple Summary: Inert dusts including diatomaceous earths and zeolites have been proved very effective as grain protectants against stored product insects. However, little progress has been made towards the evaluation of their insecticidal activity when applied directly to different types of surfaces. In this study, we evaluated two diatomaceous earth formulations and one zeolite deposit from Greece when applied to concrete and steel against three major stored product insect pests. Based on the results, both dusts achieved complete control of all insect species within a week. The type of surface was found to not be a factor of significance for the effectiveness of the dusts. These data further encourage the exploitation of these natural insecticides for structural treatments in storage facilities, either as alternatives to residual insecticides and fumigants that have been used as essential components for stored-grain protection systems, or for integrated pest management (IPM) approaches. We evaluated formulations of diatomaceous earth and zeolite originated from natural deposits from Greece as insecticides in concrete and steel surfaces for the control of three major beetle species of stored products: Sitophilus oryzae (L.) (Coleoptera: Curculionidae), Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae) and Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae). The formulations were tested as dusts at 0.5 or 1 g/m2. Our results indicated that, in most of the cases tested, the inert materials caused 100% adult mortality for all three species, even at the lowest dose, after 7 days of exposure. At the same time, there were no considerable differences in the insecticidal effect of the formulations between concrete and steel surfaces. Among the species tested, R. dominica was the most susceptible, followed by S. oryzae and T. confusum. Our results indicate that natural resource-based inert silicaceous deposits could be used with success in stored product protection against insects at dose rates that are comparable with other commercially available inert material-based formulations. [ABSTRACT FROM AUTHOR]

Mosquitoes, as hematophagous ectoparasites, are significant pests and vectors of numerous pathogens, causing diseases such as dengue, lymphatic filariasis, malaria, chikungunya, and Japanese encephalitis in India. This study investigates the potential of natural insecticides derived from plants to combat mosquito populations, focusing on botanical extract from the leave of Sphaeranthus indicus. Specifically, the hexane extract of S. indicus exhibited notable efficacy against Aedes aegypti and Culex quinquefasciatus mosquitoes. The research entailed the extraction, fractionation, and structural identification of active compounds through spectroscopic analysis. Among ten fractions isolated, fraction 4 demonstrated the highest mosquitocidal activity, leading to the identification of β-isocostic acid as the primary active compound. The study's biological assays included ovicidal, larvicidal, and pupicidal tests, revealing that β-isocostic acid exhibited significant efficacy, with ovicidal activity rates of 75.2% and 78.2% at 2 ppm against Ae. aegypti and Cx. quinquefasciatus , respectively. Larvicidal and pupicidal assays further confirmed the potent activity of β-isocostic acid, with LC 50 values of 1.02 ppm and 0.96 ppm against Ae. aegypti and Cx. quinquefasciatus larvae, and 1.20 ppm and 1.14 ppm against Ae. aegypti and Cx. quinquefasciatus pupae respectively. The isolated compound demonstrated comparable efficacy to azadirachtin and temephos, indicating its potential as a natural mosquitocidal agent. This research underscores the importance of exploring botanical sources for developing effective and environmentally sustainable mosquito control strategies, particularly in light of increasing resistance to synthetic insecticides. The findings suggest that β-isocostic acid could serve as a viable alternative to chemical mosquitocides, contributing to integrated vector management programs. [Display omitted] • First report on larvicidal, pupicidal, and ovicidal effects of β-isocostic acid. • β-isocostic acid was isolated from the leaves of Spharanthus indicus. • Characterized using IR, NMR, and GC-MS techniques. • The compound exhibited promising ovicidal, larvicidal and pupicidal efficacy. • Supports natural products as promising alternatives to synthetic insecticides. [ABSTRACT FROM AUTHOR]

Both human beings and animals around the globe are vulnerable to the transmission of infectious diseases carried by mosquitoes. They have the ability to transmit a diverse array of pathogenic agents, such as viruses and parasites, while feeding on blood. The objective of this research is to investigate andrographolide isolation, characterization, and structure elucidation from Andrographis paniculata. Furthermore, it aims to evaluate the activity of andrographolide against the immature stages of Aedes aegypti and Culex quinquefasciatus. The fractions obtained from A. paniculata extracts underwent further purification and analysis to identify the most active ones. To confirm the structure of andrographolide, spectroscopic methods including IR, 1H-NMR, 13C-NMR, and GC-MS were used. Biological assays were conducted to assess its ovicidal, larvicidal, and pupicidal activities. Importantly, andrographolide demonstrated moderate ovicidal activity, resulting in mortality rates of 36% and 32% in Ae. aegypti and Cx. quinquefasciatus eggs, respectively, at a concentration of 2 ppm. Additionally, it exhibited strong larvicidal and pupicidal efficacy, with LC 50 values of 2.02 ppm and 3.19 ppm against Ae. aegypti larvae and pupae, and 2.14 ppm and 2.73 ppm against Cx. quinquefasciatus larvae and pupae. These findings highlight the potential of andrographolide as a powerful natural compound in mosquito control efforts. Furthermore, this study underscores the importance of natural products as viable alternatives to synthetic insecticides in managing vector-borne diseases. [Display omitted] • Andrographolide isolated from methanol extract of A. paniculata leaves. • Characterized and elucidated using IR, NMR, and GC-MS techniques. • Exhibited significant ovicidal, larvicidal, and pupicidal activity in Ae. aegypti and Cx. quinquefasciatus. • Emphasizes natural products as eco-friendly alternatives to synthetic insecticides. [ABSTRACT FROM AUTHOR]

Spodoptera frugiperda is a major pest of maize crops. The application of synthetic insecticides and the use of Bt maize varieties are the principal strategies used for its control. However, due to the development of pesticide resistance and the negative impact of insecticides on the environment, natural alternatives are constantly being searched for. Accordingly, the objective of this review was to evaluate the use of essential oils (EOs) as natural alternatives for controlling S. frugiperda. This review article covers the composition of EOs, methods used for the evaluation of EO toxicity, EO effects, and their mode of action. Although the EOs of Ocimum basilicum, Piper marginatum, and Lippia alba are the most frequently used, Ageratum conyzoides, P. septuplinervium. O. gratissimum and Siparuna guianensis were shown to be the most effective. As the principal components of these EOs vary, then their mode of action on the pest could be different. The results of our analysis allowed us to evaluate and compare the potential of certain EOs for the control of this insect. In order to obtain comparable results when evaluating the toxicity of EOs on S. frugiperda, it is important that methodological issues are taken into account. [ABSTRACT FROM AUTHOR]

The leaf extract of Melia azedarach L. was obtained by soaking plant material in ethanol for one week and its toxic effect was assessed on the third instar larvae of khapra beetle (Trogoderma granarium Everts). Four concentrations of the extract (2, 4, 6 & 8 µL mL-1 acetone) were applied through contact method in Petri plates. Mortality was recorded after 12, 24 and 36 h. All the concentrations showed toxic effects against the larvae to variable extents. The highest mortality i.e. 72% was recorded at 8 µL mL-1 acetone concentration after 36 h incubation period. At the same concentration, the mortality was 61.67% and 48.34% after 24 and 12 h, respectively. Minimum mortality (23.33%) was observed at 2 µL mL -1 acetone concentration after 12 h. GC-MS analysis of ethanolic leaf extract of parthenium revealed the phytol as the predominant compound with 72.25% peak area. Other compounds were 2(4H)-benzofuranone, 5,6,7,7a-tetrahydro-4,4,7a-trimethyl-(6.30%), 1-(3,6,6-trimethyl-1,6,7,7a-tetrahydrocyclopenta[c]pyran-1-yl)ethanone (6.11%), methyl stearate (4.60%), (+/-)-phytone (4.38%), hexadecanoic acid, methyl ester (3.24%), and hexadecanoic acid, ethyl ester (3.12%). It is concluded that an 8 µL mL-1 acetone concentration of leaf extract of M. azedarach can kill up to 72% larvae of T. granarium in 36 hours. [ABSTRACT FROM AUTHOR]

Mosquitoes transmit pathogens which cause human and mammalian diseases. We employed several practical and multidisciplinary approaches to discover a new natural mosquito repellent. The active ingredient tests revealed that bamboo vinegar (BV) showed 91 % protective efficacy. The forearm skin landing test showed that 9% acetic acid water solution (AA WS) and BV had strong protective efficacy againstAedes albopictus. The limb skin landing test also showed that BV and AA WS had protective efficacy. The sugar-feeding behavioral bioassay showed that mosquitoes were repelled by the smell of AAWS. There was no significant difference between the number of mosquitoes that landed on the two Petri dishes treated with BV (6.6% acetic acid (AA)), 4.5% AAWS, 9% AAWS, and 4.5% DEBT, but a significant difference was found among BV (6.6% AA), 4.5%AAWS, 9.0%AAWS, DEBT, and distilled water. The arm-in-cage tests showed that there was a descending order for the duration of complete protection was DEBT (75-90 min) = BV (75-90 min) >formic acid (60- 75 min) > AA (45- 60 min) > propanoic acid (30-45 min) > butanoic acid (15-30 min) > water (0 min). The safety tests showed that the acute oral toxicity (LD50) ofBV (6.6% AA) was > 5000 mg/kg for mice and produced no red spots or edema symptoms. Furthermore, the dermal sensitization rate was zero for rabbits, and the marrow micronucleus rates for mice were negative. In summary, BV can be safely used for volatilization and skin applications. [ABSTRACT FROM AUTHOR]

Abstract Background Azadirachtin A is a triterpenoid from neem tree exhibiting excellent activities against over 600 insect species in agriculture. The production of azadirachtin A depends on extraction from neem tissues, which is not an eco-friendly and sustainable process. The low yield and discontinuous supply of azadirachtin A impedes further applications. The biosynthetic pathway of azadirachtin A is still unknown and is the focus of our study. Results We attempted to explore azadirachtin A biosynthetic pathway and identified the key genes involved by analyzing transcriptome data from five neem tissues through the hybrid-sequencing (Illumina HiSeq and Pacific Biosciences Single Molecule Real-Time (SMRT)) approach. Candidates were first screened by comparing the expression levels between the five tissues. After phylogenetic analysis, domain prediction, and molecular docking studies, 22 candidates encoding 2,3-oxidosqualene cyclase (OSC), alcohol dehydrogenase, cytochrome P450 (CYP450), acyltransferase, and esterase were proposed to be potential genes involved in azadirachtin A biosynthesis. Among them, two unigenes encoding homologs of MaOSC1 and MaCYP71CD2 were identified. A unigene encoding the complete homolog of MaCYP71BQ5 was reported. Accuracy of the assembly was verified by quantitative real-time PCR (qRT-PCR) and full-length PCR cloning. Conclusions By integrating and analyzing transcriptome data from hybrid-seq technology, 22 differentially expressed genes (DEGs) were finally selected as candidates involved in azadirachtin A pathway. The obtained reliable and accurate sequencing data provided important novel information for understanding neem genome. Our data shed new light on understanding the biosynthesis of other triterpenoids in neem trees and provides a reference for exploring other valuable natural product biosynthesis in plants.

We evaluated formulations of diatomaceous earth and zeolite originated from natural deposits from Greece as insecticides in concrete and steel surfaces for the control of three major beetle species of stored products: Sitophilus oryzae (L.) (Coleoptera: Curculionidae), Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae) and Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae). The formulations were tested as dusts at 0.5 or 1 g/m2. Our results indicated that, in most of the cases tested, the inert materials caused 100% adult mortality for all three species, even at the lowest dose, after 7 days of exposure. At the same time, there were no considerable differences in the insecticidal effect of the formulations between concrete and steel surfaces. Among the species tested, R. dominica was the most susceptible, followed by S. oryzae and T. confusum. Our results indicate that natural resource-based inert silicaceous deposits could be used with success in stored product protection against insects at dose rates that are comparable with other commercially available inert material-based formulations.

Nowadays, the insecticidal and acaricidal properties of plant extracts and essential oils (EOs) have been evaluated as an alternative to chemical means. This study aims to assess the insecticidal efficacy of 20 commercial EOs against the adults of Musca domestica Linnaeus (Diptera: Muscidae) by the contact of insects with the residues of EOs at the bottom of glass cups. The dose effects of seven EOs (i.e. Acorus calamus, Allium sativum, Syzygium aromaticum, Cymbopogon citratus, Juniperus communis, Cedrus atlantica, and Foeniculum vulgare) as well as the time effects of exposure to these EOs on the mortality of flies were analyzed by probit analysis. Permethrin (technical substance) was used as a reference insecticide in the positive control and pure acetone served as the negative control. The insecticidal efficacy of the tested EOs decreased in order (based on their lethal dose (LD)50 values): A. calamus > A. sativum > S. aromaticum ≥ C. citratus > J. communis > C. atlantica > F. vulgare. A. calamus EO was the most effective against flies and very fast acting with negligible reversibility of effect. The EOs of A. sativum and S. aromaticum had a significant time-dependent insecticidal effect. The time for 50% insecticidal effect (knockdown and mortality in total) of the A. sativum EO was the greatest among the seven EOs and seven times more in comparison with the positive control. Present results and literature data suggest that the aforesaid plant products could be promising as contact insecticides against adults M. domestica. The difference in the insecticidal properties of A. calamus and A. sativum EOs observed in the current study display the need for various approaches for their future application as insecticides. [ABSTRACT FROM AUTHOR]

Spodoptera frugiperda is a major pest of maize crops. The application of synthetic insecticides and the use of Bt maize varieties are the principal strategies used for its control. However, due to the development of pesticide resistance and the negative impact of insecticides on the environment, natural alternatives are constantly being searched for. Accordingly, the objective of this review was to evaluate the use of essential oils (EOs) as natural alternatives for controlling S. frugiperda. This review article covers the composition of EOs, methods used for the evaluation of EO toxicity, EO effects, and their mode of action. Although the EOs of Ocimum basilicum, Piper marginatum, and Lippia alba are the most frequently used, Ageratum conyzoides, P. septuplinervium. O. gratissimum and Siparuna guianensis were shown to be the most effective. As the principal components of these EOs vary, then their mode of action on the pest could be different. The results of our analysis allowed us to evaluate and compare the potential of certain EOs for the control of this insect. In order to obtain comparable results when evaluating the toxicity of EOs on S. frugiperda, it is important that methodological issues are taken into account.

Pyrethrum is a perennial herbaceous plant endemic to the eastern coast of the Adriatic Sea, and introduced in large areas of nearly all continents, where it is cultivated for the industrial extraction of pyrethrins. Pyrethrins are a group of six closely related monoterpene esters, widely used as natural insecticides. The world production of natural pyrethrins is lower than the market demand, and a wider introduction of this crop within the Mediterranean agrosystems could be an appealing opportunity for farmers and manufacturers. The availability of adequate amounts of selected plant material to bring into cultivation is, however, one of the major issues. Therefore, the in vitro propagation of elite pyrethrum genotypes could be a suitable alternative to conventional propagation methods. In this paper, we present the results of a 9-year field comparison between pyrethrum plants coming from an in vitro propagation protocol and plants obtained by cutting from the same mother plants. Furthermore, since plantlets derived from in vitro regeneration may experience ploidy changes, we evaluated the stability of the ploidy level of pyrethrum-micropropagated plants by flow cytometry (FCM) analysis. FCM screening revealed no differences among the morphotypes and between them and the mother plant. Likewise, the field evaluation of plants gave no significant differences between flower yields in both groups. Hence, micropropagation was confirmed as an easy, efficient and reproducible method to obtain large quantities of selected pyrethrum genotypes.

Cochliomyia hominivorax is the dipteran that causes the worst and most serious types of myiasis in animals and humans in the Americas. The data described here show the effects of a commercial product formulated on the basis of citronella essential oil nanoemulsified (Nano Citronela Plus®) directly on eggs, first, second and third stage larvae of the C. hominivorax blowfly, in addition to the indirect effect on the oviposition of adult flies. These data make up the gross base that was used in the preparation of the article “Repellent, ovicidal, larvicidal and adulticidal action of a nanoemulsion of Citronella essential oil (Cymbopogon winterianus) on Cochliomyia hominivorax (Diptera: Calliphoridae)” Bricarello et al., 2021. Counting data of larvae, eggs and adult flies live and dead after contact with the product, data on weighing and counting of eggs from the repellency test are available, as well as photos of cuticular changes that occurred in the larvae and malformations observed after contact with Nano Citronela Plus®.

[Display omitted] • Nanoemulsified Citronella EO 15% is lethal for eggs of C. hominivorax. • Nanoemulsified Citronella EO 15% is lethal for larvae of C. hominivorax. • Nanoemulsified Citronella EO 15% reduces the oviposition of C. hominivorax. • Adult of C. hominivorax are sensitive to nanoemulsified Citronella EO 15%. Cochliomyia hominivorax is the dipteran that causes the worst and most serious types of myiasis in animals and humans in the Americas. They are parasitic affections caused by the massive infestation of larvae of this species on the tissues of living mammals. The routine treatment uses chemosynthetic products that have high toxicity and can cause several injuries to animal and human health, besides environmental contamination. The development of more friendly alternatives to the treatment of this disease is an important knowledge gap nowadays. Citronella (Cymbopogon winterianus) is the most widely cultivated medicinal plant in tropical and subtropical regions. Essential oils have a recognised repellent and larvicidal activity against a wide variety of insects. This work aimed to evaluate the repellent, ovicidal and larvicidal efficacy of a topical commercial formulation composed of 15% (w/v) nanoemulsified Citronella essencial oil (Nano Citronela Plus®) in in vitro trials on specimens of C. hominivorax created under laboratory conditions. Nano Citronela Plus® is an oil-in-water nanoemulsion obtained by high-pressure homogenization method. The composition of tested nanoemulsion was Cymbopogon winterianus essential oil, vanillin, caprylic/capric triglyceride, polysorbate 80, sorbitan oleate, tocopheryl acetate, sodium benzoate and water. Nano Citronela Plus® demonstrated 100% lethality on eggs and first and second stage larvae of C. hominivorax. Mortality in the larvae of third stage was 69.33% and inhibited the oviposition of C. hominivorax females. Nano Citronela Plus® proved to be a possible herbal alternative for the control and treatment of myiasis caused by C. hominivorax. In vivo studies may test this hypothesis. [ABSTRACT FROM AUTHOR]

European fruit lecanium, Parthenolecanium corni (Bouché, 1844) is among the leading worldwide pests of fruits such as plums, currants, jostaberry, grapevine and many others. This study is focused on testing the effectiveness of natural insecticide treatments compared with conventional insecticides on overwintering nymphs of the European fruit lecanium. In February of 2017, two experiments were conducted under laboratory conditions. The tested products were Boundary SW® (plant extract), Konflic® (plant extract), Ekol® (canola oil) and a tank-mix of Ekol® + Reldan 22® (canola oil and chlorpyrifos-methyl) as a chemical standard. The most effective product tested was the chemical standard tank-mix of Ekol® and Reldan 22®, which was 100% effective in all experiments. High efficiency was also achieved with Ekol® (canola oil) in high concentrations. We can summarize, that using canola oil in high concentration has almost the same effect as the chemical standard. Using canola oil against European fruit lecanium meets the principles of Integrated Pest Management (IPM) and also the need to design cropping systems that are less dependent on synthetic pesticides.

The Mediterranean basin thrives in native plant species are able to produce numerous derivatives that can be used for insect pest control. This article provides an up-to-date overview of the most important native plant species commonly found in this region that have a certain insecticidal value in vegetable crops. Regarding the insecticidal activity of extracts from selected native species, results from both laboratory and field experiments will be also presented to highlight the potential of the latter as alternatives to synthetic insecticides. Considering the great diversity in ingredients among the various plant species, it is essential to record and describe the chemical composition of these species, in conjunction with their insecticidal activity against the main insect pests of vegetable crops. The review concludes in underlining the critical points for increasing the effectiveness and consequently the practical use of natural insecticides in crop protection. Moreover, emphasis is given in understanding the importance of the production of standardized and stable natural resource-based insecticides through the development of suitable formulations, such as capsule suspension that protects the active ingredients from environmental degradation and improves their residual activity. [ABSTRACT FROM AUTHOR]

The insecticidal compound pyrethrin is synthesized in Dalmatian pyrethrum ( Tanacetum cinerariifolium (Trevis.) Sch.Bip.; Asteraceae), a plant species endemic to the eastern Mediterranean. Pyrethrin is a mixture of six compounds, pyrethrin I and II, cinerin I and II, and jasmolin I and II. For this study we sampled 15 natural Dalmatian pyrethrum populations covering the entire natural distribution range of the species; Croatian coastal regions and the islands, inland Bosnia and Herzegovina and Montenegro. The plants were grown in a field experiment under uniform growing conditions to exclude a short-term response to environmental factors and instead observe variation in pyrethrin content and composition among and within populations due to genetic adaptation to the native environment. The drivers of local adaptation were explored by examining the role of bioclimatic factors as a cause of population differentiation. Pyrethrins were extracted by ultrasound-assisted extraction, and the extracts were analyzed by HPLC-UV-DAD. The populations differed significantly in the content and composition of pyrethrins. The highest levels of total pyrethrins (1.27% flower DW), were found in population P14 Budva and the significantly highest levels of pyrethrin I in population P14 Vranjske Njive, Podgorica (66.47% of total pyrethrin). Based on bioclimatic conditions of the sampling sites, populations were grouped into five bioclimatic groups (A, B, C, D, and E), which showed qualitative and quantitative variability in pyrethrin content. The most abundant bioclimatic group was bioclimatic group E, which was characterized by the highest average values for pyrethrin I (53.87% of total pyrethrin), total pyrethrin content (1.06% flower DW) and the ratio of pyrethrin I and II (1.85). The correlation analysis between the pyrethrin compounds and some of the bioclimatic variables (e. g., BIO03 Isothermality and BIO04 Temperature seasonality) showed their significant contribution in explaining the variation of pyrethrins in T. cinerariifolium . The differences in pyrethrin content and composition may be partly due to genetic adaptation to the ecological conditions of the native environment. The obtained data would enable the selection of source populations for breeding programs aimed at producing cultivars with desirable biochemical properties and adaptation to different bioclimatic conditions., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Grdiša, Jeran, Varga, Liber, Turudić and Šatović.)

Helicoverpa punctigera (native budworm) is an important pest species in crops across Australia. From the third instar onward, this species causes severe damage to crop plants: therefore, caterpillars need to be managed at an early stage of their development. In our experiment, we raised H. punctigera on an artificial diet, which included different concentrations of the natural insecticides Spinetoram and Azadirachtin. The survival of the larvae, growth and body mass gain was recorded over 17 days. Only caterpillars raised on lowest toxin concentrations survived and molted successfully to the fifth instar, but had slower growth and body mass gain compared to the insecticide-free control group. Caterpillars fed on higher toxin concentrations never molted to the next instar or died in the first few days. To test how the toxins influence physiological conditions including metabolic rate and water loss, surviving fifth instar larvae were exposed to thermolimit respirometry: starting at 25°C following a constant increasing temperature ramping rate of 0.25°C–1, until reaching the critical thermal maxima (CTmax). Caterpillars raised on a non-lethal dose of insecticides had higher metabolic rates and lost more water compared to the control group. Insects that have seem to consume more energy per mg tissue and have a higher water loss at high temperatures. Non-lethal concentrations of insecticides on pest insects physiology may reduce their impact on crops and may enable more targetted insecticide application.

Abstract Background Celastrus angulatus Maxim is a kind of crucial and traditional insecticidal plant widely distributed in the mountains of southwest China. Celangulin V is the efficient insecticidal sesquiterpenoid of C. angulatus and widely used in pest control in China, but the low yield and discontinuous supply impeded its further popularization and application. Fortunately, the development of synthetic biology provided an opportunity for sustainable supply of Celangulin V, for which understanding its biosynthetic pathway is indispensable. Results In this study, six cDNA libraries were prepared from leaf and root of C. angulatus before global transcriptome analyses using the BGISEQ-500 platform. A total of 104,950 unigenes were finally obtained with an average length of 1200 bp in six transcriptome databases of C. angulatus, in which 51,817 unigenes classified into 25 KOG classifications, 39,866 unigenes categorized into 55 GO functional groups, and 48,810 unigenes assigned to 135 KEGG pathways, 145 of which were putative biosynthetic genes of sesquiterpenoid and triterpenoid. 16 unigenes were speculated to be related to Celangulin V biosynthesis. De novo assembled sequences were verified by Quantitative Real-Time PCR (qRT-PCR) analysis. Conclusions This study is the first report on transcriptome analysis of C. angulatus, and 16 unigenes probably involved in the biosynthesis of Celangulin V were finally collected. The transcriptome data will make great contributions to research for this specific insecticidal plant and the further gene mining for biosynthesis of Celangulin V and other sesquiterpene polyol esters.

With the purpose of finding plant compounds with the potential use as herbicides and insecticides, a research was realized with the objective of evaluate the phytotoxic and dissuasive activity of four Chihuahua desert plants. The phytotoxic activity evaluation was tested on Lactuca sativa and Lolium perenne, while the dissuasive activity was realized on three species of phytophagous insects: Myzus persicae, Rhopalosiphum padi and Spodoptera littoralis. Raw extracts were used, the solvents hexane, methanol and ethanol of different plants’ organs (root, steam, leaf and flower) of four species: Fouquieria splendens (ocotillo), Larrea tridentate (governor), Astragalus mollissimus (wild grass) and Pachycereus pecten-aboriginum (echo), by the establishment of in vitro bioassays at a concentration of 10 mg/ml extract/solvent. In the toxicity bioassay, the percentage of germination, root and leaf length were measured. The results showed that the leaf extract of L. tridentata had phytotoxic activity for L. sativa, while for L. perenne the phytotoxicity was observed within the ocotillo, governor and echo extracts. In the dissuasive bioassay, each treatment had 20 repetitions with 10 adult insects per repetition. The methanolic extracts of F. splendens leaf and root, ethanolic extract of A. mollisimus sheet and the ethanolic extract of P. pecten-aboriginum stems showed moderate dissuasive response of feeding against M. persicae, presenting a settlement inhibition index of 53.53, 54.35, 60.00 and 48.84% respectively. Nevertheless, the results indicated that none of the 10 extracts tested on S. littoralis showed significant dissuasive properties for this Lepidoptera, while for R. padi all the tested extracts presented dissuasive properties. The treatments of the four vegetable species evaluated showed defensive or dissuasive properties of moderate to strong feeding against the insects M. persicae and R. padi, presenting interesting potential for being used as insecticides, while the tested extracts that presented phytotoxicity for both lettuce and ryegrass present possibilities for the realization of herbicides.

Natural pyrethrin insecticides produced by Dalmatian pyrethrum (Tanacetum cinerariifolium) have low mammalian toxicity and short environmental persistence, providing an alternative to widely used synthetic agricultural insecticides that pose a threat to human health and the environment. A recent surge of interest in the use of pyrethrins as agricultural insecticides coincides with the discovery of several new genes in the pyrethrin biosynthetic pathway. Elucidation of this pathway facilitates efforts to breed improved pyrethrum varieties and to engineer plants with improved endogenous defenses or hosts for heterologous pyrethrin production. We describe the current state of knowledge related to global pyrethrum production, the pyrethrin biosynthetic pathway and its regulation, and recent efforts to engineer the pyrethrin pathway in diverse plant hosts. Pyrethrin insecticides produced by Tanacetum cinerariifolium provide a human-safe and ecologically sound alternative to widely used synthetic insecticides. The development of transcriptomic and genomic resources for T. cinerariifolium facilitated the elucidation of numerous steps in the pyrethrin biosynthetic pathway. Pyrethrin biosynthetic genes have been engineered into diverse plant hosts; these efforts demonstrate the promise of engineering plants with improved endogenous defenses or of the development of an alternative source to pyrethrins for use as insecticides. [ABSTRACT FROM AUTHOR]

Laboratory bioassays were conducted to evaluate the insecticidal efficacy of a diatomaceous earth deposit from Greece, for a wide range of stored product insects. In this context, populations of five different insect species, Tribolium confusum Jacquelin DuVal, the confused flour beetle; Sitophilus oryzae (L.), the rice weevil; Rhyzopertha dominica (F.), the lesser grain borer; Oryzaephilus surinamensis (L.), the sawtoothed grain beetle; Cryptolestes ferrugineus (Stephens), the rusty grain beetle, which cover a major spectrum of insects species of stored products worldwide, were used in the bioassays. The different treatment of diatomaceous earth (DE) rocks (grinding, diatomaceous enrichment, powder granulometry) led to the creation of five types of formulations (namely DE1, DE2, DE3, DE5 and DE6) that exhibited significant fluctuations in their insecticidal efficacy when applied on wheat. In general, some of the modified formulations were found to be very effective against species such as R. dominica and T. confusum that may be difficult to control at the current labeled doses of commercial DE formulations. Overall, our data clearly indicate that this specific Greek deposit has considerable insecticidal properties, which can be further utilized in designing commercial formulations for insect control at the postharvest stages of durable agricultural commodities, provided that the deposit will be modified at specific enrichment and granulometry levels. [ABSTRACT FROM AUTHOR]

Helicoverpa punctigera (native budworm) is an important pest species in crops across Australia. From the third instar onward, this species causes severe damage to crop plants: therefore, caterpillars need to be managed at an early stage of their development. In our experiment, we raised H. punctigera on an artificial diet, which included different concentrations of the natural insecticides Spinetoram and Azadirachtin. The survival of the larvae, growth and body mass gain was recorded over 17 days. Only caterpillars raised on lowest toxin concentrations survived and molted successfully to the fifth instar, but had slower growth and body mass gain compared to the insecticide-free control group. Caterpillars fed on higher toxin concentrations never molted to the next instar or died in the first few days. To test how the toxins influence physiological conditions including metabolic rate and water loss, surviving fifth instar larvae were exposed to thermolimit respirometry: starting at 25°C following a constant increasing temperature ramping rate of 0.25°C–1, until reaching the critical thermal maxima (CT max ). Caterpillars raised on a non-lethal dose of insecticides had higher metabolic rates and lost more water compared to the control group. Insects that have seem to consume more energy per mg tissue and have a higher water loss at high temperatures. Non-lethal concentrations of insecticides on pest insects physiology may reduce their impact on crops and may enable more targetted insecticide application. [ABSTRACT FROM AUTHOR]

Insecticidal action of plant essential oils has been an area of intensive research in the new millennium, according to a recent bibliometric analysis. Despite this overwhelming research effort, commercialization of bioinsecticides based on essential oils has lagged far behind, although such products have now been used in the USA for over a decade, and in the EU in the last 4–5 years. Recent progress in commercialization of these products is reviewed here. Essential oils and their mono- and sesquiterpenoid constituents are fast-acting neurotoxins in insects, possibly interacting with multiple receptor types. These compounds also display potentially important sublethal behavioural effects in pest insects, including feeding and oviposition deterrence and repellence. Synergy among essential oil terpenoids appears to be a common phenomenon, and a mechanism for this action in rosemary oil has recently been demonstrated. Commercial development of bioinsecticides based on plant essential oils can follow several different pathways producing products with active ingredients differing in their genesis. These include products whose active ingredients consist of (1) a mixture of essential oils; (2) a single essential oil, or a single terpenoid constituent; (3) a blend of terpenoids, synthetically produced, that emulate those in a plant essential oil; and (4) a novel (non-natural) blend of terpenoids obtained from different plant sources. Examples of each of these are provided. [ABSTRACT FROM AUTHOR]

This study evaluated the influence of temperature and relative humidity (RH) on the insecticidal effect of diatomaceous earth (DE) at two concentrations, 500 and 1000 ppm, on wheat, for the control of Cryptolestes ferrugineus (Stephens) (Coleoptera: Cucujidae), Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae), and Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae). These bioassays were carried out in all combinations of four temperature levels (15, 20, 25, and 30 °C), and two relative humidity levels (55 and 75%). Cryptolestes ferrugineus and O. surinamensis were found to be much more susceptible to the DE-treated wheat than T. confusum, but the increase of the DE dose increased the mortality level for all three species. Although the increase of temperature and the decrease of RH increased insect mortality in some of the combinations tested, the reverse was observed in some treatments, suggesting that there are considerable differential effects of these factors in DE efficacy. The increase of insect exposure from 1 to 21 days notably increased insect mortality, suggesting that exposure is a critical factor that may alleviate possible differential effects of certain abiotic conditions. The results of the present work provide data that illustrate the viability of the utilization of DE in stored product protection, as alternatives to chemical control methods.

According to the European Directive 2009/128/EC and the subsequent provisions activated in member states, conventional pesticides should be progressively replaced by “non-chemical tools and/or measures”. The identification of reliable alternatives to pesticides is crucial to achieve this objective. A European project (PURE) was funded to investigate this topic with reference to annual and perennial crops. In this framework, a number of natural insecticides, in particular microbial and botanical ones (Bacillus thuringiensis ssp. kurstaki, Beauveria bassiana, azadirachtin, pyrethrins and spinosad) were selected to test their effectiveness against grape berry moths, the key pests in most European vineyards. Trials were conducted in 2011 and 2012 in two experimental vineyards located in Italy (Tuscany and Veneto regions), following a randomized block design. Additional investigations were carried out in the Veneto region during 2013. Trial results stressed the high performance of spinosad and B. thuringiensis in controlling berry moth densities and the related damage. The use of B. bassiana mixed with B. thuringiensis did not significantly improve the impact of B. thuringiensis alone. Azadirachtin, and especially pyrethrins, proved to be less effective on berry moths than previous insecticides. The use of selected insecticides caused side-effects on a number of secondary pests, in particular leafhoppers. In 2011, densities of Empoasca vitis were higher in spinosad-treated plots probably because of a reduced egg parasitization rate. One year later, the population density of Zygina rhamni was higher in the plots treated with spinosad or pyrethrins. This trend was confirmed on spinosad-treated plots in the last experimental year. At the same time, spinosad and pyrethrins significantly reduced the predatory mite populations compared to other treatments. The use of these insecticides in viticulture is discussed in the framework of organic viticulture and Integrated Pest Management (IPM).

• Insecticidal effect of Tithonia diversifolia was evaluated against the fall armyworm. • Fraction A reduced the pupal weight. • Fractions B and C increased the duration of the larval phase. • Sesquiterpene lactones reduced the larval period and pupal weight. Plant extracts can be used as an alternative to synthetic insecticides for the control of insect pests. This work aimed to evaluate the insecticidal effect of the ethyl acetate fractions and sesquiterpene lactones from Tithonia diversifolia (Asteraceae) leaf extract against the fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae). As a result, we found that the fraction A (20% methanol (MeOH)) at 100 ppm reduced pupal weight by 12.2% compared to the control. Fractions B (40% MeOH) and C (60% MeOH) at 100 ppm increased the duration of the larval period by 1.87 and 2.03 days, respectively. The sesquiterpene lactones tagitinin A (1), tagitinin C (2) and 1 β -methoxydiversifolin (3) at 100, 50 and 10 ppm affected the larval development with reduction of the larval period and pupal weight. Neither the fractions nor the pure compounds interfered with the duration of the pupal phase, nor did they cause larval or pupal mortality. [ABSTRACT FROM AUTHOR]

The current methods employed to mitigate losses caused by Phthorimaea operculella primarily rely on the application of synthetic insecticides. We have utilised essential oils of Mentha spicata L. and Artemisia absinthium against Phthorimaea operculella . The essential oils were obtained using hydrodistillation and analysed via gas chromatography-mass spectrometry. Mentha spicata essential oil contained D-limonene (25.12%) and D-carvone (7.47%) while the essential oil of Artemisia absinthium was rich of 3,3,5-trimethylcyclohexene (27.93%) and camphor (22.50%). Five concentrations (0, 1, 2, 4, and 8 µL/L of air) were applied to the four phases of P. operculella , neonate larvae, nymphs, eggs and adults. The results of the biological tests showed that spearmint oil was more toxic than wormwood oil, particularly at the adult and Chrysalide stages. Essential oils could be considered good alternatives to chemical pesticides for the protection of potato crops.

With the purpose of finding plant compounds with the potential use as herbicides and insecticides, a research was realized with the objective of evaluate the phytotoxic and dissuasive activity of four Chihuahua desert plants. The phytotoxic activity evaluation was tested on Lactuca sativa and Lolium perenne, while the dissuasive activity was realized on three species of phytophagous insects: Myzus persicae, Rhopalosiphum padi and Spodoptera littoralis. Raw extracts were used, the solvents hexane, methanol and ethanol of different plants' organs (root, steam, leaf and flower) of four species: Fouquieria splendens (ocotillo), Larrea tridentate (governor), Astragalus mollissimus (wild grass) and Pachycereus pecten-aboriginum (echo), by the establishment of in vitro bioassays at a concentration of 10 mg/ml extract/solvent. In the toxicity bioassay, the percentage of germination, root and leaf length were measured. The results showed that the leaf extract of L. tridentata had phytotoxic activity for L. sativa, while for L. perenne the phytotoxicity was observed within the ocotillo, governor and echo extracts. In the dissuasive bioassay, each treatment had 20 repetitions with 10 adult insects per repetition. The methanolic extracts of F. splendens leaf and root, ethanolic extract of A. mollisimus sheet and the ethanolic extract of P. pecten-aboriginum stems showed moderate dissuasive response of feeding against M. persicae, presenting a settlement inhibition index of 53.53, 54.35, 60.00 and 48.84% respectively. Nevertheless, the results indicated that none of the 10 extracts tested on S. littoralis showed significant dissuasive properties for this Lepidoptera, while for R. padi all the tested extracts presented dissuasive properties. The treatments of the four vegetable species evaluated showed defensive or dissuasive properties of moderate to strong feeding against the insects M. persicae and R. padi, presenting interesting potential for being used as insecticides, while the tested extracts that presented phytotoxicity for both lettuce and ryegrass present possibilities for the realization of herbicides. [ABSTRACT FROM AUTHOR]

European fruit lecanium, Parthenolecanium corni (Bouché, 1844) is among the leading worldwide pests of fruits such as plums, currants, jostaberry, grapevine and many others. This study is focused on testing the effectiveness of natural insecticide treatments compared with conventional insecticides on overwintering nymphs of the European fruit lecanium. In February of 2017, two experiments were conducted under laboratory conditions. The tested products were Boundary SW® (plant extract), Konflic® (plant extract), Ekol® (canola oil) and a tank-mix of Ekol® + Reldan 22® (canola oil and chlorpyrifos-methyl) as a chemical standard. The most effective product tested was the chemical standard tank-mix of Ekol® and Reldan 22®, which was 100% effective in all experiments. High efficiency was also achieved with Ekol® (canola oil) in high concentrations. We can summarize, that using canola oil in high concentration has almost the same effect as the chemical standard. Using canola oil against European fruit lecanium meets the principles of Integrated Pest Management (IPM) and also the need to design cropping systems that are less dependent on synthetic pesticides. [ABSTRACT FROM AUTHOR]

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Summary: In the natural pesticides known as pyrethrins, which are esters produced in flowers of Tanacetum cinerariifolium (Asteraceae), the monoterpenoid acyl moiety is pyrethric acid or chrysanthemic acid.We show here that pyrethric acid is produced from chrysanthemol in six steps catalyzed by four enzymes, the first five steps occurring in the trichomes covering the ovaries and the last one occurring inside the ovary tissues.Three steps involve the successive oxidation of carbon 10 (C10) to a carboxylic group by TcCHH, a cytochrome P450 oxidoreductase. Two other steps involve the successive oxidation of the hydroxylated carbon 1 to give a carboxylic group by TcADH2 and TcALDH1, the same enzymes that catalyze these reactions in the formation of chrysanthemic acid. The ultimate result of the actions of these three enzymes is the formation of 10‐carboxychrysanthemic acid in the trichomes. Finally, the carboxyl group at C10 is methylated by TcCCMT, a member of the SABATH methyltransferase family, to give pyrethric acid. This reaction occurs mostly in the ovaries.Expression in N. benthamiana plants of all four genes encoding aforementioned enzymes, together with TcCDS, a gene that encodes an enzyme that catalyzes the formation of chrysanthemol, led to the production of pyrethric acid. [ABSTRACT FROM AUTHOR]

[Display omitted] • InertPMS, DiaHerb, DEBBM, and DEA were the most effective DEs. • InertPMS killed all T. castaneum parental individuals at 125 ppm after 3 days. • InertPMS, DiaHerb, DEBBM, and DEA suppressed progeny at 125 ppm. • DiaFil 610 was the least effective DE for adult mortality and progeny. The utilization of diatomaceous earths (DEs) has been considered as a potential alternative to traditional insecticides for controlling grain storage insect pests. In this study, 19 different commercial DEs obtained from various regions of the world were evaluated for their effectiveness to manage Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), in vitro. Two different series of bioassays were carried out, with the first screening all 19 DEs and the second evaluating the eight most effective ones at different doses and exposure intervals for mortality assessment and progeny production. Four enhanced DEs, namely InertPMS, DEA, DiaHerb, and DEBBM were highly effective compared to other DEs tested. InertPMS exhibited complete adult mortality at 50 mg/kg, followed by DEA at 75 mg/kg, DiaHerb at 100 mg/kg, and DEBBM at 125 mg/kg, while GrainGuard exhibited 94.52 % at 125 mg/kg, 14 days post-exposure. Protect-It, SilicoSec, and DiaFil 610 were less effective at 400 mg/kg, causing 87.3 %, 84.4 %, and 79.2 % mortality after 14 days, respectively. The offspring was suppressed in wheat treated with InertPMS at 75 mg/kg, while DEA, DiaHerb, and DEBBM revealed no progeny emergence at 125 mg/kg. GrainGuard, Protect-It, SilicoSec, and DiaFil 610 were not successful at progeny suspension after 62 days. These findings suggest that the use of specific DEs at low doses could be a viable option to mitigate the use of conventional insecticides and diminish the residues of insecticides on stored grains, making them the most feasible components for integrated pest management (IPM) in stored grain systems. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this work was to assess the fumigant and repellent effects of essential oils on adults of Callosobruchus maculatus and to identify the chemical composition of two of the tested essential oils. For the fumigation test, the oils of Schinus terebinthifolius, Piper aduncum, Syzygium aromaticum, Piper hispidinervum, Cymbopogon citratus, Cinnamomum zeylanicum, and the eugenol compound were tested at different concentrations on C. maculatus adults. For the repellency test, the oils of S. terebinthifolius, P. aduncum, P. hispidinervum, S. aromaticum, Jatropha curcas, and Ricinus communis were evaluated. In the fumigation test, it was observed that P. aduncum and eugenol showed the highest and lowest LC50s, of 169.50 and 0.28 μL L-1 air, respectively. In the repellency test, the oils of S. aromaticum and P. hispidinervum were repellent to C. maculatus. Gas chromatography coupled to mass spectrometry (GC-MS) analysis of these two oils identified 42 compounds, of which safrole was the main component of P. hispidinervum and eugenol of S. aromaticum. The essential oils of S. aromaticum, C. zeylanicum, and the eugenol compound are the most promising to control C. maculatus, via fumigation.

Solanaceous plants have a great economic impact in Egypt. These groups of plants include potatoes, tomatoes and eggplants. The new invasive pest of tomatoes, Tuta absoluta (Meyrick) causes the greatest crop losses which can range from 60 to 100%. After its detection in Egypt during the last half of 2009, it spread quickly to all provinces in the country. We aiming to propose a sustainable control program for this devastating pest. In this research we tested three groups of control agents. The first was microbial and natural, the second - plant extracts and the third - chemical insecticides. Our results showed that the impact of T. absoluta can be greatly reduced by the use of sustainable control measures represented by different insecticide groups. Bioassay experiments showed that this devastating pest can be controlled with some compounds that give high mortality rates. Of these compounds, spinosad and Beauveria bassiana, microbial control agents, followed by azadirachtin, gave the best results in controlling T. absoluta. Of the chemical insecticides, lambda-cyhalotrin was the most effective, followed by lufenuron and profenofos. In conclusion we encourage farmers to use microbial and natural control measures in combating the tomato leafminer, T. absoluta, in Integrated Pest Mangement (IPM) programs.

Laboratory bioassays were conducted to evaluate the insecticidal efficacy of a diatomaceous earth deposit from Greece, for a wide range of stored product insects. In this context, populations of five different insect species, Tribolium confusum Jacquelin DuVal, the confused flour beetle; Sitophilus oryzae (L.), the rice weevil; Rhyzopertha dominica (F.), the lesser grain borer; Oryzaephilus surinamensis (L.), the sawtoothed grain beetle; Cryptolestes ferrugineus (Stephens), the rusty grain beetle, which cover a major spectrum of insects species of stored products worldwide, were used in the bioassays. The different treatment of diatomaceous earth (DE) rocks (grinding, diatomaceous enrichment, powder granulometry) led to the creation of five types of formulations (namely DE1, DE2, DE3, DE5 and DE6) that exhibited significant fluctuations in their insecticidal efficacy when applied on wheat. In general, some of the modified formulations were found to be very effective against species such as R. dominica and T. confusum that may be difficult to control at the current labeled doses of commercial DE formulations. Overall, our data clearly indicate that this specific Greek deposit has considerable insecticidal properties, which can be further utilized in designing commercial formulations for insect control at the postharvest stages of durable agricultural commodities, provided that the deposit will be modified at specific enrichment and granulometry levels.

Background: Celastrus angulatus Maxim is a kind of crucial and traditional insecticidal plant widely distributed in the mountains of southwest China. Celangulin V is the efficient insecticidal sesquiterpenoid of C. angulatus and widely used in pest control in China, but the low yield and discontinuous supply impeded its further popularization and application. Fortunately, the development of synthetic biology provided an opportunity for sustainable supply of Celangulin V, for which understanding its biosynthetic pathway is indispensable. Results: In this study, six cDNA libraries were prepared from leaf and root of C. angulatus before global transcriptome analyses using the BGISEQ-500 platform. A total of 104,950 unigenes were finally obtained with an average length of 1200 bp in six transcriptome databases of C. angulatus, in which 51,817 unigenes classified into 25 KOG classifications, 39,866 unigenes categorized into 55 GO functional groups, and 48,810 unigenes assigned to 135 KEGG pathways, 145 of which were putative biosynthetic genes of sesquiterpenoid and triterpenoid. 16 unigenes were speculated to be related to Celangulin V biosynthesis. De novo assembled sequences were verified by Quantitative Real-Time PCR (qRT-PCR) analysis. Conclusions: This study is the first report on transcriptome analysis of C. angulatus, and 16 unigenes probably involved in the biosynthesis of Celangulin V were finally collected. The transcriptome data will make great contributions to research for this specific insecticidal plant and the further gene mining for biosynthesis of Celangulin V and other sesquiterpene polyol esters. [ABSTRACT FROM AUTHOR]

Detoxifying pathways of mosquitoes against the neem (Azadirachta indica) extracts are still unclear. The aim of the present study was to investigate the role of adenosine triphosphate–binding cassette (ABC) transporters in this process in Anopheles stephensi, one of the main malaria vectors in southern Asia. Third-stage larvae of An. stephensi were fed with fish food alone or in combination with neem extract at 0.5%, 1%, 5%, and 10%. Six ABC-transporter genes from 3 different subfamilies (B, C, and G) were analyzed to assess their relative expression compared with controls. A bioassay was also performed to assess larval mortality rate at different concentrations and in combination with verapamil, an ABC-transporter inhibitor. No significant variation in the expression levels of any transporter belonging to the B, C, and G subfamilies was detected. Furthermore, the use of verapamil did not induce an increase in mortality at any of the tested neem extract concentrations, indicating that ABC transporters are not involved in the detoxification of neem extracts in An. stephensi larvae. [ABSTRACT FROM AUTHOR]

Extracts and compounds from the Chilean plants canelo, Drimys winteri J.R. Forst. & G. Forst. (Winteraceae), tabaco del diablo, Lobelia tupa L. (Campanulaceae), huevil, Vestia foetida Hoffmans. (Solanaceae) and violeta, Viola portalesia Gay (Violaceae) were evaluated against Sitophilus granarius L. (Coleoptera: Curculionidae), one of the most widespread and destructive primary pests of stored cereals. Total extracts at concentrations of 2.5% w / w in diets, over 6-days, display insecticidal effects against S. granarius . D. winteri caused the mortality of 87.5% of insects; L. tupa 80%, V. foetida 5 6% whereas V. portalesia killed 45% of insects under the same conditions. In an effort to determine the active compounds, the extracts of Lobelia tupa and Drimys winteri were purified by preparative chromatography. The piperidine alkaloid lobelanidine was isolated from L. tupa and the drimane sesquiterpenes drimenin, drimenol and polygodial were isolated as the major components in the extract from D. winteri . The purified compounds compounds displayed insecticidal activity against S. granarius in a concentration/dependent-time manner (% mortality at 0.5% w / w over 6-days): polygodial 80%, drimenol 60%, lobelanidine 47%, and drimenin 20%. In agreement with these results, grains treated with polygodial showed greater protection against the feeding attack by the granary weevil. These results provide evidence of the importance of elements of the native Chilean flora as new potential sources of botanical pesticides for the insect pest control. [ABSTRACT FROM AUTHOR]