Inhalation bioaccessibility of imidacloprid in particulate matter: Implications for risk assessment during spraying.

Adverse health outcomes due to the inhalation of pesticide residues in atmospheric particulate matter (PM) are gaining global attention. Quantitative health risk assessments of pesticide inhalation exposure highlight the need to understand the bioaccessibility of pesticide residues. Herein, the inhalation bioaccessibility of imidacloprid in PM was determined using three commonly used in vitro lung modeling methods (Artificial Lysosomal Fluid, Gamble Solution, and Simulated Lung Fluid). To validate its feasibility and effectiveness, we evaluated the bioavailability of imidacloprid using a mouse nasal instillation assay. The in vitro inhalation bioaccessibility of imidacloprid was extracted using Gamble Solution with a solid-liquid ratio of 1/1000, an oscillation rate of 150 r/min, and an extraction time of 24 h, showed a strong linear correlation with its in vivo liver-based bioavailability (R2 =0.8928). Moreover, the margin of exposure was incorporated into the inhalation exposure risk assessment, considering both formulations and nozzles. The inhalation unit exposure of imidacloprid for residents was 0.95-4.09 ng/m3. The margin of exposure for imidacloprid was determined to be acceptable when considering inhalation bioaccessibility. Taken together, these results indicate that the inhalation bioaccessibility of pesticides should be incorporated into assessments of human health risks posed by PM particles.

Ecological Toxicity of Cyantraniliprole against Procambarus clarkii: Histopathology, Oxidative Stress, and Intestinal Microbiota.

Cyantraniliprole is a novel insecticide recently introduced for rice pest control that may cause potential threats to the red swamp crayfish (Procambarus clarkii) in rice-crayfish coculture systems. In this study, we investigated the acute toxicity of cyantraniliprole against P. clarkii with a LC50 value of 149.77 mg/L (96 h), first. Some abnormal behaviors of P. clarkii treated with 125 mg/L cyantraniliprole, including incunabular hyperexcitability, imbalance, inactivity, and increased excretion were observed. Moreover, it was observed that exposure to 5 mg/L cyantraniliprole for 14 days resulted in histopathological alterations in abdominal muscle, gills, hepatopancreas, and intestines. Furthermore, exposure to 0.05 and 5 mg/L cyantraniliprole induced increased activities of several oxidative stress-related enzymes, which was verified by the upregulation of related genes. Additionally, dysregulation of the intestinal microbiota was determined via 16S rRNA sequencing. These results will provide the basis for the utilization of cyantraniliprole in the fields of rice-crayfish integrated system.

Residue Behavior of Chiral Fungicide Prothioconazole and Its Major Chiral Metabolite in Flour Product Processing.

This study systematically investigates the stereoselective metabolism and residue behavior of chiral pesticide prothioconazole enantiomers during the steaming, baking, and frying of steamed buns, bread, and deep-fried dough sticks. The results show that steaming, baking, and frying can significantly promote the degradation of the prothioconazole enantiomers. In low- and high-concentration treatments, the degradation rates of prothioconazole enantiomers were over 96.0% and 45.4%, respectively, and the residual concentration of prothioconazole-desthio enantiomers was less than 32.7 µg/kg (excluding fried processing). During the processing of steamed buns, bread, and deep-fried dough sticks, the enantiomer fraction (EF) value of the prothioconazole enantiomer was close to 0.5, and the stereoselectivity was not significant. During the processing of steamed buns (low concentration), bread (low and high concentrations), and deep-fried dough sticks (low concentration), the stereoselectivity of prothioconazole-desthio was significant, and preferential enantiomer degradation occurred. Following the analysis of 120 flour product samples, the residual risk.

In vitro inhalation bioaccessibility and health risk assessment of difenoconazole in the atmosphere.

BACKGROUND: Assessment of the risk of pesticide inhalation in populations around farmland is necessary because inhalation is one of the ways in which pesticides can risk human health. This study aimed to identify the inhalation risk of difenoconazole on humans by using dose-response and exposure assessments. RESULTS: In the field simulation application, respiratory exposure in populations around farmland ranged from 71 to 430 ng/m3 . Using response surface methodology, the maximum bioaccessibility of difenoconazole in three simulated lung fluids was 35.33% in Gamble's solution (GS), 34.12% in artificial lysosomal fluid (ALF), and 42.06% in simulated interstitial lung fluid (SLF). Taking the proliferation activity of the A549 cell model as the endpoint, the benchmark dose limit and benchmark dose of difenoconazole on A549 cells were 16.36 and 5.60 mg/kg, respectively. The margin of exposure to difenoconazole in GS, ALF and SLF were, respectively, 8.66 × 105 to 5.28 × 106 , 8.97 × 105 to 5.47 × 106 and 7.28 × 105 to 4.44 × 106 . CONCLUSION: The risk assessment results indicate that under all circumstances, applying difenoconazole is safe for populations around farmland. However, a fan-shaped nozzle, suspension concentrate and greater inhalation height increase the risk of inhalation. © 2023 Society of Chemical Industry.

Risk assessment of honeybee larvae exposure to pyrethroid insecticides in beebread and honey.

Honeybee is an essential pollinator to crops, evaluation to the risk assessment of honeybee larvae exposure to pesticides residue in the bee bread and honey is an important strategy to protect the bee colony due to the mixture of these two matrices is main food for 3-day-old honeybee larvae. In this study, a continuous survey to the residue of five pyrethroid insecticides in bee bread and honey between 2018 and 2020 from 17 major cultivation provinces which can be determined as Northeast, Northwest, Eastern, Central, Southwest, and Southern of China, there was at least one type II pyrethroid insecticide was detected in 54.7 % of the bee bread samples and 43.4 % of the honey. Then, we assayed the acute toxicity of type II pyrethroid insecticides based on the detection results, the LD50 value was 0.2201 µg/larva (beta-cyhalothrin), 0.4507 µg/larva (bifenthrin), 2.0840 µg/larva (fenvalerate), 0.0530 µg/larva (deltamethrin), and 0.1640 µg/larva (beta-cypermethrin), respectively. Finally, the hazard quotient was calculated as larval oral ranged from 0.046 × 10-3 to 2.128 × 10-3. Together, these empirical findings provide further insight into the accurate contamination of honey bee colonies caused by chemical pesticides, which can be used as a valuable guidance for the beekeeping industry and pesticide regulation.

In vivo-in vitro correlations (IVIVC) for the assessment of pyrethroid bioavailability in honey.

Bioaccessibility/bioavailability is an important factor in assessing the potential human health risk via oral exposure. However, methods for accurately predicting the bioaccessibility/bioavailability of pesticide residues are still limited, preventing accurate measurements of actual exposure to pesticide residues. In this study, pyrethroid bioavailability in honey were analysed using a mouse bioassay and bioaccessibility via in vitro methods with Tenax extraction. The results demonstrated that the combined liver plus kidney data served as an appropriate biomarker to estimate the relative bioavailability. Notably, significant in vivo-in vitro correlations (IVIVC) were observed between bioavailability and bioaccessibility (R2 = 0.7898-0.9793). Estimation of the bioavailability of honey from different nectar plants using derived IVIVC confirmed that different contents and physicochemical properties might affect its bioavailability. The findings provide insight into assessing human exposure to pesticides based on bioavailability and can decrease the uncertainty about the assessment of the risk of dietary exposure to pesticides.

Digestion dynamics of acetamiprid during royal jelly formation and exposure risk assessment to honeybee larva based on processing factor.

Previous studies to the exposure effects of acetamiprid on honeybees were based on the analysis of bee pollen and honey sacs from field trials or of beebread and honey in the hive, which overestimate or underestimate the risk of exposure to pesticide residues. It was believed that the processing factor (PF) is an important variable to determine the final pesticide residue during royal jelly formation and the actual risk to honeybee larva. Hence, a QuEChERS method to determine acetamiprid contents in honeybee samples was established in this study. Then, the PFs for acetamiprid in beebread fermentation, honey brewing, and royal jelly formation were determined to be 0.85, 0.76, and 0.16, respectively. The PF for royal jelly formation was 0.04 when acetamiprid was detected in beebread alone, and it was 0.12 when acetamiprid was only detected in honey. Finally, the predicted exposure concentration of acetamiprid in royal jelly was calculated to be 2.05 µg/kg using the PF without significant difference with the 90th percentile value (3.64 µg/kg) in the actual sample. However, the value was 16.62 µg/kg without considering the PF. This study establishes a methodology for the correct evaluation of the risk to bee larva of acetamiprid residues in bee pollen and honey sac contents and the residual levels in royal jelly.

Incorporating Bioaccessibility into Inhalation Exposure Assessment of Emamectin Benzoate from Field Spraying.

The inhalation exposure of pesticide applicators and residents who live close to pesticide-treated fields is a worldwide concern in public health. Quantitative assessment of exposure to pesticide inhalation health risk highlights the need to accurately assess the bioaccessibility rather than the total content in ambient air. Herein, we developed an in vitro method to estimate the inhalation bioaccessibility of emamectin benzoate and validated its applicability using a rat plasma pharmacokinetic bioassay. Emamectin benzoate was extracted using the Gamble solution, with an optimized solid-to-liquid ratio (1/250), extraction time (24 h), and agitation (200 rpm), which obtained in vitro inhalation bioaccessibility consistent with its inhalation bioavailability in vivo (32.33%). The margin of exposure (MOE) was used to assess inhalation exposure risk. The inhalation unit exposures to emamectin benzoate of applicators and residents were 11.05-28.04 and 0.02-0.04 ng/m3, respectively, varying markedly according to the methods of application, e.g., formulations and nozzles. The inhalation risk assessment using present application methods appeared to be acceptable; however, the MOE of emamectin benzoate might be overestimated by 32% without considering inhalation bioaccessibility. Collectively, our findings contribute insights into the assessment of pesticide inhalation exposure based on bioaccessibility and provide guidance for the safe application of pesticides.

Mechanism and Kinetics of Prothioconazole Photodegradation in Aqueous Solution.

This study investigated the effects of light source, pH value, and NO3- concentration on the photodegradation of prothioconazole in aqueous solution. The half-life (t1/2) of prothioconazole was 173.29, 21.66, and 11.18 min under xenon, ultraviolet, and high-pressure mercury lamps, respectively. At pH values of 4.0, 7.0, and 9.0 under a xenon lamp light source, the t1/2 values were 693.15, 231.05, and 99.02 min, respectively. Inorganic substance NO3- clearly promoted the photodegradation of prothioconazole, with t1/2 values of 115.53, 77.02, and 69.32 min at NO3- concentrations of 1.0, 2.0, and 5.0 mg L-1, respectively. The photodegradation products were identified as C14H15Cl2N3O, C14H16ClN3OS, C14H15Cl2N3O2S, and C14H13Cl2N3 based on calculations and the Waters compound library. Furthermore, density functional theory (DFT) calculations showed that the C-S, C-Cl, C-N, and C-O bonds of prothioconazole were the reaction sites with high absolute charge values and greater bond lengths. Finally, the photodegradation pathway of prothioconazole was concluded, and the variation in energy of the photodegradation process was attributed to the decrease in activation energy caused by light excitation. This work provides new insight into the structural modification and photochemical stability improvement of prothioconazole, which plays an important role in decreasing safety risk during application that will reduce the exposure risk in field environment.

Residue behavior of cyantraniliprole and its ecological effects on Procambarus clarkii associated with the rice-crayfish integrated system.

BACKGROUND: Cyantraniliprole, a second-generation diamide insecticide, was recently introduced in China, where the rice-crayfish integrated system (RCIS) is practiced to control rice pest infestations. The aim of this study was to investigate the residue behavior of cyantraniliprole in RCIS and its potential ecological effects on nontarget Procambarus clarkii in order to recommend safe pesticide application strategies. RESULTS: Cyantraniliprole dissipated in rice plants according to first-order kinetics, with an average half-life of 5.25 days and a dissipation rate of >95% over 28 days. The terminal cyantraniliprole residue levels in rice straw, paddy hull and brown rice were all within 0.2 mg kg-1 , which is the China-recommended maximum residue limit. The tissues of P. clarkii accumulated and distributed cyantraniliprole in the descending order gill > hepatopancreas > intestine > muscles. Procambarus clarkii exposed to cyantraniliprole exhibited a moderate decrease in weight gain, specific growth rate and condition factor compared to the control group. Exposure of P. clarkii to cyantraniliprole caused histopathological alterations to the hepatopancreas, but the alterations were not statistically significant in the 60 g ai ha-1 cyantraniliprole group when compared with the control group. CONCLUSION: We suggest that 10% cyantraniliprole oil dispersion be sprayed twice at an interval of 14 days and dosage of 60 g ai ha-1 during the growth stage of rice in RCIS. © 2023 Society of Chemical Industry.

Inhalation bioaccessibility of inhaled triazole fungicides and health risk assessment during spraying.

BACKGROUND: Ambient air pollution caused by pesticide drift has received great attention. To accurately evaluate the health risk of inhaled pesticides, bioaccessibility should be considered. However, methods to reliably assess pesticide residues remain limited, hindering the precise estimation of exposure assessment. We aimed to optimize an in vitro method for the inhalation bioaccessibility (IBA) measurement of triazole fungicides and to incorporate this into inhalation exposure assessment during pesticide spraying. RESULTS: The IBA of triazole fungicides increased logarithmically with extraction duration, plateauing after 6 h. The frequency of agitation displayed a similar pattern, whereas the ratio of solid to liquid between 1/1500 and 1/250 was considerably negatively associated. The predicted values (35.9-53.5%) for IBA based on optimized methodological parameters determined using a response surface methodology showed an acceptable deviation from experimental values (30.7-50.8%), suggesting feasibility for in vitro IBA measurement. Incorporating IBA into calculations of inhalation exposure amount (IE) yielded a value of 8.5 × 10-7 -2.1 × 10-5  mg kg-1 day-1 , a 50-68% reduction compared to IE based on total amount. Additionally, the safety exposure threshold was determined for triazole fungicides using benchmark dose modelling of data from lung A549 cell proliferation toxicity assays, and in this context, margin of exposure (MOE) values were calculated to be within an acceptable level. CONCLUSION: This in vitro method supplements bioaccessibility evaluation based on pesticide inhalation exposure, along with the risk to human health. © 2023 Society of Chemical Industry.

Supervised machine learning algorithms to predict the duration and risk of long-term hospitalization in HIV-infected individuals: a retrospective study.

Objective: The study aimed to use supervised machine learning models to predict the length and risk of prolonged hospitalization in PLWHs to help physicians timely clinical intervention and avoid waste of health resources. Methods: Regression models were established based on RF, KNN, SVM, and XGB to predict the length of hospital stay using RMSE, MAE, MAPE, and R2, while classification models were established based on RF, KNN, SVM, NN, and XGB to predict risk of prolonged hospital stay using accuracy, PPV, NPV, specificity, sensitivity, and kappa, and visualization evaluation based on AUROC, AUPRC, calibration curves and decision curves of all models were used for internally validation. Results: In regression models, XGB model performed best in the internal validation (RMSE = 16.81, MAE = 10.39, MAPE = 0.98, R2 = 0.47) to predict the length of hospital stay, while in classification models, NN model presented good fitting and stable features and performed best in testing sets, with excellent accuracy (0.7623), PPV (0.7853), NPV (0.7092), sensitivity (0.8754), specificity (0.5882), and kappa (0.4672), and further visualization evaluation indicated that the largest AUROC (0.9779), AUPRC (0.773) and well-performed calibration curve and decision curve in the internal validation. Conclusion: This study showed that XGB model was effective in predicting the length of hospital stay, while NN model was effective in predicting the risk of prolonged hospitalization in PLWH. Based on predictive models, an intelligent medical prediction system may be developed to effectively predict the length of stay and risk of HIV patients according to their medical records, which helped reduce the waste of healthcare resources.

Toxic effects of detected pyrethroid pesticides on honeybee (Apis mellifera ligustica Spin and Apis cerana cerana Fabricius).

To obtain the presence of environmental contaminants in honeybee and compare the toxicity of the detected pesticides to Apis mellifera ligustica Spin and Apis cerana cerana Fabricius. In this work, 214 honeybee samples were collected to simultaneous monitoring 66 pesticides between 2016 and 2017 in China. A modified QuEChERS extraction method coupled with multi-residue analytical methods by Ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and Gas chromatography-mass spectrum (GC-MS). Among, four pyrethroid pesticides were selected to test and compare the acute oral toxicities of two honeybees. And the survival risk of beta-cypermethrin was analyzed to them. Using this method, 21 compounds were detected, including 3 neonicotinoids, 5 pyrethroids, 5 organophosphorus and 8 others. Importantly, detected frequencies of pyrethroid pesticides were accounted for 53.3%. Among, acute toxicity values (LD50) of four pyrethroid pesticides to the A.m. ligustica were higher than of that the A.c. cerana. When they were exposed to the same concentration of beta-cypermethrin (0.2906 mg/L), the survival rate of the A.m. ligustica (40.0%) was higher than the A.c. cerana (18.9%). Our work is valuable to analyze multiple pesticide residues of honeybees and evaluate the survival risk of two honeybee species, which also provides a basis for the risk assessment.

Incorporating Tenax into the in vitro method to improve the predictive capability of bioaccessibility of triazole fungicides in grape.

In vitro bioaccessibility assays have been developed for high-throughput prediction of relative bioavailability (RBA). However, methods to reliably and efficiently assess pesticide residues remain limited, hindering the precise estimation of pesticide exposure risk. The inclusion of a sorption sink material to simulate intestinal sorption could be a promising approach to optimize in vitro bioaccessibility methods. The current study aimed to explore the feasibility of incorporating Tenax into the Rijksinstituut voor Volksgezondheid en Milieu (RIVM) method for accurate evaluation of the bioaccessibility of triazole fungicides. The use of 1.0 g of Tenax enabled the valid trapping of triazole fungicides released from grape, resulting in a significant increase of 23.59-38.51 % in the value of bioaccessibility. A strong in vivo-in vitro correlation was observed between pesticide RBA and bioaccessibility, suggesting that the Tenax-assisted RIVM method is a suitable replacement for time-consuming and laborious in vivo alternatives. In addition, the exposure assessment indicated that the hazard quotients for triazole fungicides in grape may be overestimated by 5.79-27.34 % without considering bioaccessibility based on the Tenax-assisted RIVM method. These results provide further insights into the assessment of bioaccessibility-based human exposure to pesticides as well as dietary exposure and related risk for human health.

Effect of formulation on the indoxacarb and lufenuron dissipation in maize and risk assessment.

The supervised field trials were conducted in maize crops using nano-microemulsion (NM) and a commercial formulation of indoxacarb and lufenuron to evaluate the effect of nano-formulation on the dissipation pattern. A modified QuEChERS (Quick Easy Cheap Effective Rugged and Safe)-UPLC-MS/MS (ultra-performance liquid chromatography tandem mass spectrometry) method was utilized for sample analysis. Results showed that the initial deposits of indoxacarb and lufenuron in plants using nano-microemulsion were 0.98 mg/kg and 8.18 mg/kg at recommended dosage, while using the commercial formulation, they were 0.85 mg/kg and 5.53 mg/kg, respectively. Moreover, half-life (t1/2) values of using nano-microemulsion were 1.25 days and 2.51 days, which were shorter than indoxacarb (1.87 days) and lufenuron (3.00 days) from the commercial formulation, suggesting that pesticide formulations have a moderate impact on the initial deposit and dissipation rate. The terminal residue test showed that indoxacarb and lufenuron residues in maize grain and maize straw were below the available maximum residue limit (MRL, 0.01 mg/kg), suggesting 2% indoxacarb NM and 5% lufenuron NM are safe to use under the recommended dosage. The risk quotient value (RQ of indoxacarb and lufenuron equal to 17.7% and 2.4%, respectively) also revealed an acceptable risk for human consumption. These findings provide scientific evidence of the proper application of 2% indoxacarb NM and 5% lufenuron NM on maize crops.

Gut microbiota-involved metabolism and intestinal absorption mechanisms in decreasing bioaccessibility of triadimefon in strawberry and grape.

Gut microbiota-involved metabolism and intestinal absorption affecting bioaccessibility of triadimefon in strawberry and grape were investigated for the first time by coupling the in vitro digestion model with the Caco-2 cell model. Results showed that the gut microbiota decreased the bioaccessibility of triadimefon in strawberry by 31.00% but failed in grape, probably due to a negative modulation of the colon bacterial activity by dietary components in grapes. A strain of triadimefon-degrading bacteria, Stenotrophomonas maltophilia, was isolated from the gut microbiota and its degradation products were profiled. This study also clarified a significant reduction in transepithelial transport (up to 32.81%) of triadimefon as a result of the barrier effect of gut microbiota. These findings provide new insights on the function of the gut microbiota in pesticide bioaccessibility and highlight the importance of including gut microbiota in pesticide residue risk assessments.

The effects of beta-cypermethrin, chlorbenzuron, chlorothalonil, and pendimethalin on Apis mellifera ligustica and Apis cerana cerana larvae reared in vitro.

BACKGROUND: Declines in bee populations and diversity have drawn international attention. The long-term use of chemical pesticides has affected bee behavior and physiology. This study aimed to investigate the effects of chronic exposure to four commonly used chemical pesticides (beta-cypermethrin, chlorbenzuron, chlorothalonil and pendimethalin) on the growth of Apis mellifera ligustica and Apis cerana cerana larvae reared in vitro. RESULTS: Pesticide type and concentration were the main factors affecting honeybee fitness. Beta-cypermethrin and chlorbenzuron had chronic toxic effects on bee larvae. They reduced the fitness of A. m. ligustica and A. c. cerana even at low doses of 323.5 ng g-1 for beta-cypermethrin and 62.6 ng g-1 for chlorbenzuron in bee bread. The effects were positively associated with the dietary amounts of pesticides. By contrast, chlorothalonil and pendimethalin exposure did not affect bee larvae despite changes in enzyme activities. Caution is still needed with chlorothalonil, which led to a decrease in harvest adult bee numbers at a high dose (6937.2 ng g-1 ). Furthermore, a difference in pesticide resistance was observed, suggesting that A. m. ligustica may tolerate toxic effects better than A. c. cerana. CONCLUSION: This study sheds new light on chronic toxicity in bee larvae exposed to residues in bee bread. The results could guide the scientific and rational use of chemical pesticides to reduce the potential risks to A. m. ligustica and A. c. cerana. © 2021 Society of Chemical Industry.

Analysis of honey bee exposure to multiple pesticide residues in the hive environment.

Since the loss of honeybees in hives could have a greater impact on colony health than those of their foraging bees, it is imperative to know beehives' pesticide exposure via oral ingestion of contaminated in-hive matrices. Here, a 4-year monitoring survey of 64 pesticide residues in pollen, nectar and related beehive matrices (beebread and honey) from China's main honey producing areas was carried out using a modified version of the QuEChERS multi-residue method. The results showed that 93.6% of pollen, 81.5% of nectar, 96.6% of beebread, and 49.3% of honey containing at least one target pesticide were detected either at or above the method detection limits (MDLs), respectively, with up to 19 pesticides found per sample. Carbendazim was the most frequently detected pesticide (present in >85% of the samples), and pyrethroids were also abundant (median concentration = 134.3-279.0 µg/kg). The transfer of pesticides from the environment into the beehive was shown, but the pesticide transference ratio may be affected by complex factors. Although the overall risk to colony health from pesticides appears to be at an acceptable level, the hazard quotient/hazard index (HQ/HI) value revealed that pyrethroids were clearly the most influential contributor, accounting for up to 45% of HI. Collectively, these empirical findings provide further insights into the extent of contamination caused by agricultural pesticide use on honeybee colonies.

Identification of Olfactory Genes From the Greater Wax Moth by Antennal Transcriptome Analysis.

The olfactory system is used by insects to find hosts, mates, and oviposition sites. Insects have different types of olfactory proteins, including odorant-binding proteins (OBPs), chemosensory proteins (CSPs), odorant receptors (ORs), ionotropic receptors (IRs), and sensory neuron membrane proteins (SNMPs) to perceive chemical cues from the environment. The greater wax moth, Galleria mellonella, is an important lepidopteran pest of apiculture. However, the molecular mechanism underlying odorant perception in this species is unclear. In this study, we performed transcriptome sequencing of G. mellonella antennae to identify genes involved in olfaction. A total of 42,544 unigenes were obtained by assembling the transcriptome. Functional classification of these unigenes was determined by searching against the Gene Ontology (GO), eukaryotic orthologous groups (KOG), and the Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. We identified a total of 102 olfactory-related genes: 21 OBPs, 18 CSPs, 43 ORs, 18 IRs, and 2 SNMPs. Results from BLASTX best hit and phylogenetic analyses showed that most of the genes had a close relationship with orthologs from other Lepidoptera species. A large number of OBPs and CSPs were tandemly arrayed in the genomic scaffolds and formed gene clusters. Reverse transcription-quantitative PCR results showed that GmelOBP19 and GmelOR47 are mainly expressed in male antennae. This work provides a transcriptome resource for olfactory genes in G. mellonella, and the findings pave the way for studying the function of these genes.

Acceptable risk of fenpropathrin and emamectin benzoate in the minor crop Mugua (Chaenomeles speciosa) after postharvest processing.

Production of minor crop varieties often requires intensive pesticide use, which raises serious concerns over food safety and human health. Chaenomeles speciosa (Sweet) Nakai as one of the representative of this kind of crops is therefore used for investigating the residue behavior of fenpropathrin and emamectin benzoate, a synthetic pyrethroid and macrocyclic lactone widely used as an insecticide, respectively, from cultivation to C. speciosa postharvest processing. Results showed that the degradation trends of those selected insecticides in C. speciosa followed first-order kinetics with an average half-life (t1/2) of 3.7-4.1 days and a dissipation rate of 97% over 14 days. The terminal residues of fenpropathrin and emamectin benzoate at 120 and 3 g a.i./ha were below the U.S Environmental Protection Agency (FAD, 1.00 mg/kg) and European Union (EU, 0.01 mg/kg) maximum residue limits (MRLs) in papaya species, respectively, when measured 14 days after the final application, which suggested that the use of these insecticides was safe for humans. Postharvest processing procedure resulted in a |90% reduction of the insecticides. Moreover, the hazard quotient (HQ) for C. speciosa decoction (with processing factors) indicated an acceptable risk for human consumption. These findings provide the scientific evidence of reasonable application and risk assessment of the selected pesticide residues in C. speciosa.