The chronic, repeated pulse of pesticides into agricultural soils is a global management standard, yet it imposes a cumulative structural stress on the microbial engine of soil health that remains insufficiently quantified. We systematically investigated this stress using two contrasting model soils: one high in organic carbon (OC-rich) and one OC-limited. We first established that pesticide dissipation kinetics are governed by a control hierarchy of habitat properties (HP), temporal stress (TS), and chemical stressor properties (CSP). To define the resulting structural outcomes, we employed absolute quantification of 16S rRNA genes, predicted functional gene analysis, and co-occurrence network analysis. Results revealed that TS drives a structural bifurcation of soil bacterial communities, where foundational habitat properties dictate the trajectory of resilience. In OC-rich soil, the community followed a path of network consolidation, marked by the selective enrichment of stress-tolerant generalists and putative functional redundancy. However, this robustness was accompanied by a predicted functional trade-off in N-cycling and an increase in secondary toxic risk (arsC-mediated arsenite mobilization). Conversely, OC-limited soil underwent network fragmentation, characterized by a significant reduction in connectivity and a decreased inferred functional gene pool. Dissipation in this fragile system relied on a few endemic, highly specialized taxa, demonstrating decoupled specialization. In conclusion, the long-term ecological fate of soil is linked to the structural integrity of the bacterial network rather than transient kinetic function. Sustainable management must shift focus to enhancing foundational HP factors (soil OC and moisture) to support structural robustness and mitigate unforeseen secondary liabilities.

Western flower thrips, Frankliniella occidentalis (Thysanoptera: Thripidae) is an invasive agricultural pest with developed resistance to abamectin in some strains due to frequent treatment with the pesticide. In this study, we examined differentially expressed proteins (DEPs) between abamectin-resistant (AbaR; under abamectin selective pressure) and susceptible strains (AbaS; without abamectin selective pressure) of F. occidentalis. Proteins were isolated from second instar larvae of both strains and separated via two-dimensional polyacrylamide gel electrophoresis. Nano-flow liquid chromatography-tandem mass spectrometry identified selected protein spot features. From 70 DEPs, 43 spot features were identified: A total of 23 showed an increase in abundance, and 20 were down-regulated in response to abamectin pressure. The enzymatic and structural proteins were classified into the functional groups of macromolecular metabolisms, signaling and cellular processes, immune system, genetic information processing, and exoskeleton-related proteins. The up-regulation of exoskeleton-related proteins may contribute to forming a thicker cuticle, potentially hindering abamectin penetration, which is an interesting finding that needs further investigation. Two novel proteins, triacylglycerol lipase and cuticle protein CPF 2, were only expressed in AbaR. This work provides insights into abamectin resistance mechanisms in F. occidentalis, which will provide important information for developing insecticide resistance management approaches for this pest.

IntroductionFipronil (FIP) and thiobencarb (THIO) represent widely utilized pesticides in paddy fields, presenting environmental challenges that necessitate effective remediation approaches. Despite the recognized need, exploring bacterial consortia efficiently degrading FIP and THIO remains limited.MethodsThis study isolated three unique bacterial consortia—FD, TD, and MD—demonstrating the capability to degrade FIP, THIO, and an FIP + THIO mixture within a 10-day timeframe. Furthermore, the bioaugmentation abilities of the selected consortia were evaluated in paddy soils under various conditions.ResultsSequencing results shed light on the consortia’s composition, revealing a diverse bacterial population prominently featuring Azospirillum, Ochrobactrum, Sphingobium, and Sphingomonas genera. All consortia efficiently degraded pesticides at 800 µg/mL concentrations, primarily through oxidative and hydrolytic processes. This metabolic activity yields more hydrophilic metabolites, including 4-(Trifluoromethyl)-phenol and 1,4-Benzenediol, 2-methyl-, for FIP, and carbamothioic acid, diethyl-, S-ethyl ester, and Benzenecarbothioic acid, S-methyl ester for THIO. Soil bioaugmentation tests highlight the consortia’s effectiveness, showcasing accelerated degradation of FIP and THIO—individually or in a mixture—by 1.3 to 13-fold. These assessments encompass diverse soil moisture levels (20 and 100% v/v), pesticide concentrations (15 and 150 µg/g), and sterile conditions (sterile and non-sterile soils).DiscussionThis study offers an understanding of bacterial communities adept at degrading FIP and THIO, introducing FD, TD, and MD consortia as promising contenders for bioremediation endeavors.

Insecticides are a major tool for controlling pest species. Their widespread use results in damage to non-targeted insects, with honey bees particularly at risk. During foraging, honey bees learn and remember floral characteristics that are associated with food. As insect pollinators, honey bees inadvertently contact chemicals which can have multiple negative impacts. The toxicity of two insecticides from different classes, ethion (47.79 mg a.i. L-1) and hexaflumuron (500 mg a.i.L-1), on learning, memory, and sensory perception were evaluated. We found that oral exposure to ethion had adverse effects on learned proboscis extension toward reward-associated odors and colors. In addition, we showed reduced sucrose consumption and sucrose responsiveness after exposure. Hexaflumuron also impaired olfactory learning and memory and decreased responsiveness to sucrose and water. Exposure to sub-lethal concentration of the cholinergic organophosphate insecticide, ethion (47.79 mg a.i. L-1), and the field-recommended concentration of hexaflumuron (500 mg a.i.L-1), significantly impaired behavior involved in foraging. Our results suggest that several behavioral characteristics of honey bees be evaluated when testing an insecticide rather than relying on just one behavioral measure.

Exposure to pesticides may affect the survival and normal physiological functions of the honey bee (Apis mellifera L.). The fungicide propiconazole (PRO) and the biofungicide Trichoderma are widely used in agroecosystems, and their effects on the physiology of the honey bee have been largely neglected in risk assessment procedures. We investigated the mortality and variations in physiological biomarkers of honey bee larvae and newly emerged workers exposed to PRO and Trichoderma. Exceeding the field-recommended concentrations of Trichoderma decreased the survival of newly emerged bee workers significantly through oral exposure. PRO, however, showed no significant lethal effects. Contact or oral exposure to field-realistic concentrations of PRO and Trichoderma profoundly altered the activities of detoxification, antioxidative, and digestive enzymes along with energy reserve concentrations of honey bee larvae and adult workers. Integrated biological index (IBRv2) values suggested potential risks of PRO and Trichoderma to honey bees by impairing the physiological status of larvae and newly emerged workers.

The carob moth, E. ceratoniae, is one of the most destructive agricultural pests worldwide. Although chemical control is a common method for managing this species, the negative impacts of synthetic insecticides on non -target species, public health, and the environment have led to an increased interest in developing safer pest control products. Pesticides based on herbal essential oils (EO) are among the most promising compounds for managing agricultural pests. In this study, we assessed the fumigant toxicity of essential oil derived from the plant F. assa-foetida towards E. ceratoniae adults. The major constituents of the oil were (Z)-1-propenyl sec -butyl disulfide (31.5%), (E)-1-propenyl sec -butyl disulfide (28.5%), and bis (1 -methyl propenyl) disulfide (12.2%). The bioassay results indicated that adult males are more susceptible than females to the EO, with LC50 values of 0.899 mu L L-1 and 1.509 mu L L-1, respectively. Investigation of detoxifying, antioxidant, and intermediary metabolism enzymes revealed that the differential susceptibility between the sexes originated in their differential enzyme activities. The results of the study indicate that there were significant differences (P < 0.05) between the treated and control groups in the levels of carboxyl esterase, catalase, ascorbate peroxidase, superoxide dismutase, alanine aminotransferase, aspartate aminotransferase, and glutamyl transferase. These findings suggest that the activity of these enzymes increased in male and female carob moths treated with the essential oil. A comparison of the activity levels of the aforementioned enzymes and energy reserves revealed sex -specific differences in neurotransmitter, antioxidant enzymes, and energy reserves. These findings suggest that these differences may play a role in the observed susceptibility variations between the two sexes. The results of this study suggest that the essential oil (EO) derived from F. assa-foetida contains components with potential insecticidal activity. Therefore, it holds promise as an environmentally friendly insecticide for integration into Integrated Pest Management (IPM) programs targeting the control of the carob moth.

IntroductionSoil bacteria offer a promising approach to bioremediate pesticide contamination in agricultural ecosystems. This study investigated the potential of bacteria isolated from rice paddy soil for bioremediating fipronil and thiobencarb, common agricultural pesticides.MethodsBacterial isolates capable of degrading fipronil and thiobencarb were enriched in a mineral salt medium. A response surface methodology with a Box-Behnken design was utilized to optimize pesticide degradation with the isolated bacteria. Bioaugmentation tests were performed in paddy soils with varying conditions.Results and discussionSix strains, including single isolates and their mixture, efficiently degraded these pesticides at high concentrations (up to 800 µg/mL). Enterobacter sp., Brucella sp. (alone and combined), and a mixture of Stenotrophomonas sp., Bordetella sp., and Citrobacter sp. effectively degraded fipronil and thiobencarb, respectively. Notably, a single Pseudomonas sp. strain degraded a mixture of both pesticides. Optimal degradation conditions were identified as a slightly acidic pH (6-7), moderate pesticide concentrations (20-50 µg/mL), and a specific inoculum size. Bioaugmentation assays in real-world paddy soils (sterile/non-sterile, varying moisture) demonstrated that these bacteria significantly increased degradation rates (up to 14.15-fold for fipronil and 5.13-fold for thiobencarb). The study identifies these novel bacterial strains as promising tools for bioremediation and bioaugmentation strategies to tackle fipronil and thiobencarb contamination in paddy ecosystems.

Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) is an important generalist predator used to control several important crops' pests such as spider mites, whiteflies, and thrips. In this study, the lethal concentrations of Mentha piperita L. (Lamiaceae) and Laurus nobilis L. (Lauraceae) essential oils (EOs) were calculated on the adult stage of the Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae). The side effects of EOs were investigated on the functional response of A. swirskii on F. occidentalis 1 st instar larvae. The females of A . swirskii were exposed to sublethal concentrations (LC30 and LC50) of EOs for 12 h with the fumigant exposure method. In the control, the treatment was performed by using Triton X-100 (0.02). Treated predatory mites were selected randomly, and transferred to the experimental arenas containing 2, 4, 8, 16, 32, and 64 thrips. The predators were kept in the experimental arenas for 24 h at 25 +/- 1 degrees C, 60 +/- 10% RH, and a photoperiod of 16: 8 h (L: D). Results indicated that A . swirskii exhibited a type II functional response, regardless of EOs applications. The shortest (1.62 +/- 0.046 h) and the longest (1.91 +/- 0.049 h) handling times, were recorded in the control and the LC50 treatment of M. piperita EO, respectively. There was not a significant difference between attack rate coefficients (alpha) under sub-lethal concentrations. Based on the results, the two EOs have the potential to be used in F. occidentalis management, but their side effects on A. swirskii should be considered in IPM programs.

This study aims to optimize the QuEChERS methodology for extracting three pesticides (fipronil, thiobencarb, and cartap) from two paddy soils with distinct characteristics. Various modifications were explored to enhance extraction efficiency, employing acetonitrile (MeCN) or ethyl acetate (EtOAc) for extraction and primary-secondary amine (PSA) and graphitized carbon black (GCB) for the clean-up. Assessment criteria included accuracy, precision, linearity, detection limits, uncertainty, and matrix effects. Results revealed that the clayey soil with lower organic carbon (OC) content (1.26%) and 100% moisture yielded the highest pesticide recoveries (113.72%, 115.73%, and 116.41% for FIP, THIO, and CART, respectively). In contrast, the silty clayey soil with higher OC content (2.91%) and 20% water content exhibited poor recoveries (< 60%). FIP and CART demonstrated better recoveries with MeCN, while THIO performed better with EtOAc under specific moisture conditions. Clean-up sorbents significantly reduced FIP and CART recoveries, with THIO recoveries less affected. Acidifying with HCl substantially improved CART recovery. EtOAc introduced a moderate to strong matrix effect for FIP and THIO, while MeCN in soils with 100% moisture resulted in a strong matrix effect for CART. The study highlighted the substantial impact of extraction conditions, pesticide properties, and soil conditions on the outcomes of the QuEChERS method. A comprehensive understanding of these interplays was deemed crucial for accurately quantifying pesticide residues in agricultural soils.

The predatory mite, Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) is one of the most promising candidates for biological control of some economically important mites and insect pests such as spider mites, whiteflies, and thrips. Western Flower Thrips (WFT), Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) is a severe economic pest for many crops in the world. In this study the lethal concentrations of Shirazicum thymus: Zataria multiflora Boiss (Lamiaceae) essential oil was calculated to the adult stage of the WFT. Side effects LC30 and LC50 of the essential oil were assessed on life table parameters and functional response of A. swirskii. Experiments were carried out in growth chambers at 25 ± 1 °C, 60 ± 10% RH, and 16: 8 h (Light: Dark) photoperiod. We utilized the age-stage, two-sex life table method to evaluate the life history features and population growth of A. swirskii on WFT. For assessing the functional response, the first instar of WFT was offered as prey to the adult female of A. swirskii with densities of 2, 4, 8, 16, 32, and 64. The LC50 concentration of the essential oil resulted in lower fecundity (15.05 eggs/female) in comparison with the control (19.8 eggs/female). The application of LC50 and LC30 concentrations also resulted in a significant decrease in net reproductive rate (R0) (8.9, 6.6, and 4.5 eggs per individuals), intrinsic rate of increase (rm) (0.116, 0.093, and 0.077 day -1), finite rate of increase (λ) (1.123, 1.097, and 1.079 day -1), but an increase in mean generation time (T) (18.5, 20.1, and 19.5 days) (for control, LC30, and LC50, applications, respectively). A type II functional response was detected for A. swirskii fed on WFT first instar in all treatments. Adult females of A.swirskii had the highest attack rate (a) (0.11± 0.01 h-1) and shortest handling time (1.61± 0.46h) on control treatment. In conclusion, although Z. multiflora essential oil had potential against F. occidentalis to be applied in integrated pest management programs, the lethal side effects of selected essential oil on the predatory mite, A. swirskii should be considered.

ABSTRACT In this study, the side effects of LC30 and LC50 concentrations of Rosmarinus officinalis L. (Lamiaceae) essential oil on the life table parameters of Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) fed on first instar Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) larvae were determined under lab conditions. The age-stage, two-sex life table method was used to evaluate the life table parameters. The net reproductive rate (R0) (8.76, 8.68 and 6.83 eggs per individual), intrinsic rate of increase (r) (0.116, 0.116 and 0.098 day −1), finite rate of increase (λ) (1.123, 1.123 and 1.103 day −1), mean generation time (T) (18.7, 18.6 and 19.6 days) and total fecundity (19.77, 19.00, and 17.70 offspring per female) acquired for control, LC30 and LC50 applications, respectively. The findings of this study indicate that using the tested essential oil, particularly the LC30, in combination with A. swirskii can be an alternative to synthetic pesticides. However, semi-field and field studies are still needed to assess the effects of the essential oil tested on F. occidentalis and A. swirskii before incorporating into integrated pest management (IPM) strategies.

Abstract The contact insecticidal activity of in natura and maltodextrin/Angum gum nanoencapsulated essential oils of Eucalyptus globulus Labill and Zataria multiflora Bioss was evaluated against the third instar larvae of Ephestia kuehniella (Lepidoptera: Pyralidae). The essential oil from E. globulus exhibited an average yield of 1.19%, and presented 1,8-cineol (59.08%) as the major component, while Z. multiflora essential oil, with an average yield of 1.5%, was characterized by thymol (26.12%) and carvacrol (25.31%) as the main components. The encapsulated particles presented spherical morphology with regular and homogeneous external surfaces, ranging from 60 to 130 nm in diameter. Laboratory bioassays estimated the contact LC50 of in natura and encapsulated essential oils as 13.07 and 1.34 µL L−1 for E. globulus and 1.47 and 5.87 µL L−1 for Z. multiflora, respectively. The results presented here, which are probably the first to be reported, suggested that essential oil nanoencapsulation represents an efficient method for enhancing both insecticidal activity and the durability of the active ingredients for sustainable pest management.

The entomopathogen Beauveria bassiana (Bals.) Vuill. (Ascomycota: Hypocreales) can colonize plants endophytically and stimulate the production of secondary plant metabolites with anti-herbivore activities. We assayed the topical virulence of B. bassiana to Aphis gossypii Glover (Hemiptera: Aphididae), the effects of cucumber inoculation with this fungus on plant metabolites, and the physiological consequences for aphids that fed on these plants. Assays were conducted with both the commercial formulation of B. bassiana, ‘Naturalis®-L’, at the recommended concentration of 1.5 ml / L (yielding a spore concentration of 2.3 × 107 CFU per ml), and with a similar concentration of the isolated fungal strain. Topical application of 0.03 ml of solution per cm2, or 1 × 103 CFU, caused 100% mortality to A. gossypii adults after seven days, whether Naturalis®-L or the isolate alone was used. The fungus grew endophytically into foliage when sprayed on cucumbers at the 2-leaf stage and concentrations of alkaloids, fl avonoids, phenols, hydrogen peroxide, and total chlorophyll were higher than in control plants 28 days after inoculation. Malondialdehyde content, plant growth, and total yield were unaffected by B. bassiana inoculation. Aphids fed on B. bassiana-inoculated plants for 24 h had reduced activities of detoxifying enzymes (glutathione-S-transferase, carboxylesterase, and acetylcholinesterase) compared to controls. Activities of digestive enzymes, (lipase, α-amylase, α-glucosidase, and aminopeptidase) were reduced in aphids from inoculated plants, which exhibited higher activities of superoxide dismutase, ascorbate peroxidase, and phenoloxidase, but lower catalase activity. Energy reserves (lipids, protein, and glycogen) were lower in aphids from inoculated plants, and they exhibited reduced fecundity, longevity, and reproductive periods, and a 50% reduction in the LC50 of pirimicarb. Thus, in addition to causing direct pathogenicity, inoculation of plants with B. bassiana negatively impacted A. gossypii physiology and reproductive performance and could usefully complement other strategies for managing cotton aphids on greenhouse cucumber. * Corresponding author; e-mail: jpmi@ksu.edu INTRODUCTION The cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae) is a polyphagous cosmopolitan pest of numerous fi eld and greenhouse crops (Ebert & Cartwright, 1997). It has the capacity for rapid population growth, causing direct feeding damage to host plants and transmitting various plant viruses (Deguine et al., 2017). Management of cotton aphids has conventionally relied on the use of synthetic insecticides (Kandil et al., 2017), which has resulted in the aphids evolving resistance to various insecticidal modes of action, and generated a need for alternative management tactics (Wang et al., 2007; Carletto et al., 2010). Eur. J. Entomol. 119: 1–11, 2022 doi: 10.14411/eje.2022.001

Intensive chemical pesticide usage in crop protection for pest control causes major pollution of the environment. Replacing chemical pesticides with biopesticide is an essential agro-ecological principle that should be considered in agro-ecosystems. In this study, a novel biopesticide formulation based on plant extract was prepared, and then aphid mortality in cucumber greenhouses was evaluated in comparison to common chemical insecticide. Our eco-friendly insecticide consists of methanolic extract of Rosmarinus officinalis (4.38 g in 1 L water) and succinic acid (0.5 g in 1 L water) in combination with Triton® X-100 (10 mL in 1 L water), canola seeds oil (10 mL in 1 L water), and potassium nitrate (5 g in 1 L water). Additionally, the common insecticide against Aphis gossypii in cucumber greenhouses is dichlorvos (Dichlorvos® 48% EC) which was applied at the recommended dose (0.6 g a.i./L). Twenty-four hours after sprayings, aphids that survived through each treatment were recorded, and mortality percentages were calculated. Results showed that in biopesticide treatment, mortality (65.6 ± 2.8%) has no significant difference compared to dichlorvos (71.1 ± 2.9%) (p = 0.0629). Finally, plant performance including numbers of leaves (p = 0.0951), flowers (p = 0.0842), fruits (p = 0.0730), and branches (p = 0.0698) were not influenced by the biopesticide application. Our results propose that the mentioned biopesticide can be used in cucumber greenhouses for aphid control with no adverse effect on plant growth and development, leading to zero-pollution tactics in crop protection, which is necessary for sustainable agriculture.

Water hardness can negatively affect the efficiency of pesticides. This study aimed to determine the effect of water hardness and adjuvants added to spray solution on the efficiency of insecticides. Three insecticides, namely, malathion, acetamiprid, and spiromesifen, were mixed in well water samples at 1,869, 645, and 265 mg L-1 hardness, standard, and deionized water, and applied against the second instar nymph of Bemisia tabaci using leaf dip method. In another experiment, Zero-7 at 150 ppm and Arkan at 180 ppm as additives were added to water with 1869 and 645 mg L-1 hardness, separately. LC50 values showed that the toxicity of malathion, acetamiprid, and spiromesifen was 40, 157, and 84 times less in hard water (1,869 mg L-1 hardness) than deionized water. The efficacy of malathion, acetamiprid, and spiromesifen was 13, 65, and 39 times less when they were diluted in water with 645 mg L-1 hardness than deionized water. Malathion provided 37.28 and 18.59% greater toxicity when applied in hard water containing Zero-7 and Arkan than water without the adjuvants. The efficacy of acetamiprid was, respectively, 16.93 and 18.68% greater when it was applied in hard water containing Zero-7 and Arkan compared to water without the additives. Zero-7 and Arkan in hard water enhanced the efficacy of spiromesifen by 10.26 and 13.68% compared to water without adjuvants. Generally, the toxicity of the insecticides on B. tabaci was considerably reduced at the highest levels of water hardness. In contrast, adjuvants overcame the antagonistic effects of cations in hard water.

Essential oils are composed of volatile components, and rapidly evaporate. It is desirable to formulate them in a cover protecting the essential oils against environmental conditions. Applying nanotechnology to preparing desirable formulations of essential oils can be provided in a cover along with controlled release, increased oil life and greater mobility. In this study, nanoparticles were prepared using polycaprolactone and chitosan aimed at encapsulation ofRosmarinus officinalisandZataria multifloraessential oils. The nanoparticles were characterized in terms of size, polydispersity, encapsulation efficiency, and scanning electron microscope photomicrographs. The nanoparticles showed a positive surface charge ranging between +11.60 and +29.20 mV and a mean particle radius ranging between 181-407 nm. Encapsulation efficiency was obtained between 75.8-84.4% under different preparation conditions. The LC(50)values of fumigant toxicity ofR. officinalisessential oil and nanoparticles were equal to 103.53 and 112.64 mu L/L air, and forZ. multifloraessential oil and nanoparticles, they were equal to 195.13 and 206.66 mu L/L air, respectively for 24 h exposure time againstTribolium confusum. The effectiveness of non- formulated essential oils was significantly (P < 0.05) lower than nanoencapsulated oils in the confused flour beetle adults for a long period under the same condition, due to the sustained release of the essentials provided by the formulation.

The honey bee is economically significant insect and plays an important role in the pollination of various plants. With regard to the widespread use of pesticides in agricultural lands, honey bees, as non-target and useful insect, inadvertently contact these chemicals. Thus, in order to evaluate the effects of some pesticides, the toxicity of three insecticides from different chemical classes including imidacloprid (0.16 mg a.i./l), ethion (79.47 mg a.i./l), and hexaflumuron (500 mg a.i./l) on detoxifying enzymes of worker honey bees and mortality of immature bees was investigated. These chemicals were selected because they are used globally and ingested by honey bees. The sub-lethal concentration of imidacloprid reduced the activity of the acetylcholinesterase (AChE) and glutathione S-transferase (GST). Exposure to the sub-lethal concentrations of the ethion reduced the esterase (EST) activities in treated honey bees. Exposure of honey bee larvae to imidacloprid (0.16 mg a.i./l), ethion (79.47 mg a.i./l), and hexaflumuron (500 mg a.i./l) increased the mortality of the treated group compared to untreated controls, but this difference was not statistically significant. Our results indicate that imidacloprid and ethion disrupt the physiology of honey bees, thereby reducing the efficiency of this beneficial pollinator. Also, it is important that additional studies be performed to investigate the sub-lethal effects of pesticides on larval development.

We examined differences in the physiology and life history between dimorphs of the common pistachio psyllid, Agonoscena pistaciae (Burckhardt and Lauterer) (Hemiptera: Aphalaridae), and how they differ in elicitating host plant production of key metabolites and volatile compounds involved in the recruitment of herbivores and natural enemies. Summer morphs had higher activities of glutathione S-transferase, carboxylesterase, acetylcholinesterase, and cytochrome P450 monooxygenase, superoxide dismutase, catalase, peroxidase, phenoloxidase, and a higher total protein content compared to winter morphs, whereas the latter had higher amounts of lipid, carbohydrate, and glycogen. Winter morphs were heavier, with a higher chitin content and longer preoviposition period, but greater fecundity and longevity than summer morphs. A lower LC50 to thiamethoxam for winter morphs resulted in higher mortality following exposure to the recommended rate of this insecticide in a greenhouse trial. Feeding by winter morphs elicited more strongly the release of volatile compounds known to be attractive to other herbivores, whereas feeding by summer morphs elicited more strongly the release of volatiles implicated in the attraction of natural enemies. Feeding by psyllids increased the concentrations of nitrogenous compounds, carbohydrates, vitamins, and amino acids in plants, the winter morph eliciting larger changes and more improved host plant quality. We conclude that winter morphs are more vulnerable targets for chemical control in early spring, whereas management of summer morphs could rely more on conservation biological control.

In order to investigate the effect of diazinon and chlorpyrifos on agricultural workers exposed to pesticides, urinary metabolites 2-Isopropyl-6-methyl-4-pyrimidinol (IMPy) and 3,5,6-Trichloro-2-pyridinol (TPCy) in farm workers, sprayer operators, and non-exposed people as a control group were measured. The modified QuEChERS method was applied to extract samples and was measured using a gas chromatograph/nitrogen-phosphorus detector. The obtained results showed that the median concentrations of TCPy were 36.92-547.7 and 7.7-49.58 ng/mL for sprayer operators and farm workers, respectively. Moreover, the median concentrations of IMPy were 81.66-593.1 ng/mL for sprayer operators and 40.6-66.1 ng/mL for farm workers. The control group had no measurable metabolites. The IMPy level of 60% of sprayer operators was significantly higher (P < 0.05) than the TCPy level. The analysis of variance highlighted the significant relationship (P < 0.05) between the levels of each metabolite and the use of safety gloves, respiratory masks, safety goggles, working time per week, and type of insecticide exposure. Our findings revealed the need to measure the urinary metabolites of these insecticides in other exposed workers. Also, workers should be taught the impact of using personal protective equipment.

Natural products derived from plant materials, such as wood vinegar (pyroligneous acid; PA), have shown toxicity to insects in previous studies; however, the impact of this substance on physiology and life history of stored product insects is unknown. Thus, the current study aimed to determine the effects of PA on two prominent stored product moths, Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae) and Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae). LC50/24h values of PA were determined for both species and first instar larvae were fed on an artificial diet containing LC50 concentrations of PA for their entire life cycle. Final instar larvae were selected for biochemical analysis while life history parameters were assayed in female adults that emerged from treated larvae. In both species, significantly lower activities of digestive enzymes (α-amylase, protease, and lipase) and detoxifying enzymes (carboxylesterase, monooxygenase cytochrome P450, and glutathione S-transferase) were observed in treated larvae relative to untreated larvae. In contrast, antioxidant enzyme activities (superoxide dismutase, phenoloxidase, and ascorbate peroxidase) were significantly elevated in treated larvae compare to controls in both species. Moreover, larvae of both species tended to have lower levels of energy reserves, such as proteins, lipids, and carbohydrates, and adults exhibited reduced longevity, fecundity, and oviposition periods in comparison to untreated larvae. Finally, GC-MS analysis of the PA used for this study demonstrated that phenolic compounds and organic acids were the largest constituents. These results indicate that consumption of PA leads to the induction of to the antioxidant system, the inhibition of detoxification and digestion enzyme activities as well as reduced levels of energy reserves. Cumulatively, these effects resulted in reduced longevity and fecundity compared to control insects. This study expands our knowledge of the impacts of PA on physiology and life history for two prominent pests of stored products.