Search Results (19)

This study aimed to evaluate residue changes in flubendiamide and tebufenozide during the processing of whole grain into milled rice, cooked rice, and rice cake, and to calculate their processing factors (PFs). For the processing study, pesticides were applied at three times the recommended rate based on Korea’s good agricultural practice (GAP), and processed products were prepared using conventional methods. Residual pesticide analysis was performed using a modified QuEChERS method and LC-MS/MS. The residue analysis method was validated based on parameters including LOQ, linearity, and accuracy at the LOQ, 10LOQ, and MRL levels, with the LOQ set at 0.01 mg/kg for all samples. During milling, which removes the hull, more than 90% of the pesticide residues were eliminated. Additional reductions exceeding 50% were observed during cooking and rice cake processing. All PFs, except for those in the hulls, were less than 1, indicating that processing reduces pesticide levels. Despite the use of threefold the GAP rate, the %ADI values for all processed products remained below 1%, suggesting negligible dietary risk. These findings provide scientific evidence supporting the safety of processed rice products regarding pesticide residues and highlight the importance of considering processing effects in dietary exposure assessments. Full article

Currently, there is no integrated pest management approach for controlling small hive beetles (Aethina tumida), a widespread honey bee (Apis mellifera) pest. To date, only hive trapping has shown any effectiveness in controlling the pest. In this study, we tested several possible active ingredients that have been shown previously to demonstrate low toxicity towards honey bees. To test their toxicities, we treated both SHBs and honey bees topically and exposed SHBs to these compounds orally via pollen. Coumaphos (industry standard), a solvent control (acetone), and a positive control (dimethoate) were used for comparisons. Thiacloprid (LD₅₀ = 1.3 ng/SHB; LC₅₀ = 12 µg/g pollen) was the most toxic active ingredient tested against SHBs both topically and through pollen. Topically, thiacloprid was 340× more toxic to SHBs than coumaphos (LD₅₀ = 431 ng/SHB). However, acetamiprid (selectivity ratio = 152) was much more toxic to SHBs than to honey bees compared to thiacloprid (selectivity ratio = 3). These findings demonstrate the need to find other active ingredients other than coumaphos and that acetamiprid has the greatest potential to reduce SHB populations safely in a honey bee hive. Field research using acetamiprid should be conducted to explore possible sub-lethal effects on honey bees. Full article

The melon fruit fly, Bactrocera cucurbitae, is an important insect pest responsible for significant yield losses in vegetables. Conventional control methods, like pesticide applications, have certain limitations, including environmental contamination. This study evaluated the chemosterilant potential of five new insect growth regulators (IGRs)—Pyriproxyfen; Novaluron; Lufenuron; Buprofezin; and Flubendiamide—at concentrations ranging from 50 to 300 ppm in a 5 mL diet against B. cucurbitae. Laboratory trials identified Lufenuron as the most effective IGR, which reduced fecundity by 68.4% and adult emergence by 70.97% at a 300 ppm concentration. Other IGRs, Pyriproxyfen; Novaluron; Buprofezin; and Flubendiamide, also significantly reduced fecundity and adult emergence at higher concentrations. Based on laboratory performance, Lufenuron was selected for field trials using six bait traps per 0.4 hectares. The field trials demonstrated a higher number of B. cucurbitae adult captures in Lufenuron-based bait traps compared to the control and reductions in crop damage, with fruit fly damage decreasing by 7.01% in August and 4.25% in September. This study highlights the potential of chemosterilant baited traps as a promising approach for integrated fruit fly management programs in cucurbitaceous vegetables. Full article

The Mediterranean Corn Borer (MCB), Sesamia nonagrioides, poses a significant threat to maize crops, necessitating effective pest management strategies. This study investigates the compatibility of two entomopathogenic nematode (EPN) isolates, Steinernema feltiae KV6 and Heterorhabditis bacteriophora EO7, with four registered insecticides for MCB control: deltamethrin, flubendiamide, spinetoram, and betacyfluthrin. The impact of these insecticides on EPN mortality, infectivity, and reproduction was assessed. Results indicate that deltamethrin exhibits the lowest toxicity to EPNs, with mortality rates of 1.3% for S. feltiae and 0.63% for H. bacteriophora at field dose (FD) after 24 h and 4.63% and 1.96%, respectively, after 48 h. In contrast, betacyfluthrin showed higher toxicity, with mortality rates of 38.04% and 14.17% for S. feltiae at 2FD and FD after 48 h. The infectivity assays demonstrated that deltamethrin-treated EPNs caused up to 100% mortality in MCB larvae, while the reproduction capacity varied significantly between the EPN species and insecticides. H. bacteriophora exhibited higher progeny production, especially in the presence of deltamethrin (87,900 IJs/larva). The findings suggest that integrating EPNs with selective insecticides like deltamethrin can enhance pest control efficacy and support sustainable agricultural practices. This study provides valuable insights for developing integrated pest management (IPM) strategies aimed at mitigating MCB infestations in maize while minimizing environmental impacts. Full article

An increase in Spodoptera species was reported in Bt soybean fields expressing Cry1Ac insecticidal proteins in Brazil, requiring additional management with chemical insecticides. Here, we evaluated the dose effects of flubendiamide and thiodicarb on Spodoptera cosmioides (Walker, 1858), Spodoptera eridania (Stoll, 1782), Spodoptera albula (Walker, 1857) and Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae) that survived on MON 87751 × MON 87708 × MON 87701 × MON 89788, expressing Cry1A.105, Cry2Ab2 and Cry1Ac; MON 87701 × MON 89788 soybean, expressing Cry1Ac; and non-Bt soybean. On unsprayed Cry1A.105/Cry2Ab2/Cry1Ac soybean, only S. frugiperda showed ~60% mortality after 10 d, whereas S. cosmioides, S. eridania and S. albula showed >81% mortality. The surviving larvae of all species on this Bt soybean showed >80% mortality when exposed to the field label dose of flubendiamide (70 mL/ha) or thiodicarb (400 g/ha) or at 50% of these doses. In contrast, all four species had <25% and <19% mortality on Cry1Ac and non-Bt soybean, respectively. The surviving S. cosmioides, S. eridania and S. albula on these soybean types presented >83% mortality after exposure to both dose levels of flubendiamide and thiodicarb. Some S. frugiperda larvae surviving on Cry1Ac and non-Bt soybean sprayed with a 50% dose of either insecticide developed into adults. However, the L1 larvae developing on Cry1Ac soybean leaves sprayed with flubendiamide and the L2 larvae on this soybean sprayed with thiodicarb had a prolonged immature stage, and the females displayed lower fecundity, which are likely to impact S. frugiperda population growth on soybean. Full article

Pesticides are commonly used to control weeds, diseases, and pests in soybean crops, although natural enemies are also key components of integrated pest management programs protecting soybean from pests. The predatory mite Neoseiulus idaeus Denmark & Muma is commonly found in soybeans associated with tetranychid mites. We determined the compatibility of some pesticides used in Brazilian soybean fields with N. idaeus on the basis of their lethal and sub-lethal effects. We assessed the acute toxicity of pesticides that are considered harmless to females of N. idaeus and evaluated the effects on the mite offspring. Acephate as well as imidacloprid and bifenthrin were most toxic to adult females and were classified as harmful. Chlorfenapyr, indoxacarb, and the neonicotinoid and pyrethroid mixtures were classified as slightly to moderately harmful. Immatures of N. idaeus were able to develop and reach the adult stage when treated with chlorantraniliprole, flubendiamide, glyphosate, and teflubenzuron, but immature survival was reduced to 42 and 64% for offspring of females treated with chlorantraniliprole or teflubenzuron, respectively. Reproduction was most affected in females exposed to chlorantraniliprole and teflubenzuron; these females had daily oviposition rates of 0.5 and 0.4 egg/female/day, respectively, and mean fecundities of 2.7 and 5.8 eggs/female, respectively. On the basis of sublethal effects and life table parameters, chlorantraniliprole was classified as moderately harmful, while the other pesticides tested were classified as harmless. In considering the use of pesticides while targeting the conservation of N. idaeus as a predator of important pests in soybean crops, one must prioritize pesticides that will most likely have less harmful effects on this predator in the field. Full article

Flubendiamide (FLB) is an insecticide that is commonly employed to control pests on a variety of vegetables and fruits, with low toxicity for non-target organisms. However, due to its widespread use, the environmental risks and food safety have become major concerns. In this study, the toxicity potential of FLB was studied in the model organisms, Allium cepa and Drosophila melanogaster. The cyto-genotoxic effects of FLB on the root growth, mitotic index (MI), chromosomal aberrations (CAs) and deoxyribonucleic acid (DNA) damage in A. cepa root meristematic cells were investigated using the root growth inhibition Allium test and Comet assays. FLB caused CAs in the form of disturbed ana-telophase, chromosome laggards, stickiness, anaphase-bridge and polyploidy depending on the concentration and the exposure time. The toxicity and genotoxicity of FLB at various doses (0.001, 0.01, 0.1 and 1 mM) on D. melanogaster were investigated from the point of view of larval weight and movement, pupal formation success, pupal position, emergence success and DNA damage, respectively. FLB exposure led to a significant reduction of the locomotor activity at the highest concentration. While DNA damage increased significantly in the FLB-treated onions depending on the concentration and time, DNA damage in the FLB-treated D. melanogaster significantly increased only at the highest dose compared to that which occurred in the control group. Moreover, to provide a mechanistic insight into the genotoxic and locomotion-disrupting effects of FLB, molecular docking simulations of this pesticide were performed against the DNA and diamondback moth (DBM) ryanodine receptor (RyR) Repeat34 domain. The docking studies revealed that FLB binds strongly to a DNA region that is rich in cytosine-guanine-adenine bases (C-G-A) in the minor groove, and it displayed a remarkable binding affinity against the DBM RyR Repeat34 domain. Full article

The purpose of this study is to investigate pesticide residues in the imported and domestic tea sold in Turkey and to detect their compliance with maximum residue limits (MRL) and Acceptable Daily Intake (ADI). A total of 79 samples were analyzed by using LC-MS/MS and GC-MS devices with AOAC 2007.01 method to investigate 603 pesticide residues. According to the results, pesticide residues were found in a total of 28 tea samples. Pesticide residues were found in the countries of origin at the rates as follows: Iran (100%), India (33.3%) and Sri Lanka (17.3%). No pesticide residue was detected in the tea produced in Turkey. The compounds such as Diuron, Ethion, Cypermethrin, Thiacloprid, Thiamethoxam, Fenpyroximate, Acetamiprid, Imidacloprid, Flubendiamide, Deltamethrin and Hexythiazox were detected in positive samples. Seven types of pesticide residues exceeded the MRL determined by the Turkish Food Codex for 15 types (53.57%) for 28 samples with pesticide residue detected. Additionally, 4 types of pesticide residues were determined to exceed the ADI determined by the Codex Alimentarius for 13 (46.42%) of 28 samples with pesticide residue detected. These results have showed that the imported tea entering Turkey was not adequately analyzed in the customs control laboratories or the maximum residual limits were not clearly determined. Full article

This study aimed to isolate, purify, and identify some bacteria from different sources known to be contaminated with pesticides and evaluate their ability to degrade two important pesticides, chlorantraniliprole (CAP), and flubendiamide (FBD). In our study, six isolates showed maximum growth in the presence of CAP and FBD in the growth media as a sole carbon source. The isolates were purified and then identified by biochemical and morphological tests, MALD-TOF-MS, and 16S rRNA techniques, as Bacillus subtilis subsp. subtilis AZFS3, Bacillus pumilus AZFS5, Bacillus mojavensis AZFS15, Bacillus paramycoides AZFS18, Pseudomonas aeruginosa KZFS4, and Alcaligenes aquatilis KZFS11. The degradation ability of studied bacterial strains against pesticides was estimated under different conditions (temperatures, pH, salt, and incubation time). The results reveal that the optimal conditions for all bacterial strains’ growth were 30–35 °C, pH 7.0, 0.0–0.5% NaCl, and an incubation period of 11 days at 150 rpm in the presence of diamide insecticides at 50 mg/L. The capacity of six bacterial strains of CO₂ production and degradation ability against various diamide pesticides and other pesticide groups (Profenofos, Cypermethrin, Carbofuran, and Malathion) were evaluated. The results show that the Pseudomonas aeruginosa KZFS4 (LC599404.1) strain produced the highest CO₂ content, about 1.226 mg CO₂/16 day, with efficacy in the biodegradation of FBD-CAP (78.6%), while the absorbance of bacterial growth (OD 600) on various pesticides ranged from 1.542 to 1.701. Additionally, Consortium-(No. 3)-mix-6-strains gave 1.553 mg CO₂/16 days with efficacy (99.6%) and turbidity of 2.122 to 2.365 (OD 600) on various pesticides. In conclusion, the six bacterial strains could play an important role in the biodegradation process of pollutants in soils. Full article

Genetically modified (GM) soybeans expressing Cry1A.105/Cry2Ab2/Cry1Ac (event MON 87701 × MON 89788 × MON 87751 × MON 87708) and Cry1Ac (event MON 87701 × MON 89788) from Bacillus thuringiensis Berliner (Bt) are valuable technologies for managing key lepidopteran pests of soybean in South America, but do not provide stand-alone protection against Spodoptera species. Here, we evaluated the use of these Bt soybeans and their integration with insecticides for managing Spodoptera species. Cry1A.105/Cry2Ab2/Cry1Ac soybean provided reasonable levels of protection against S. cosmioides, S. albula, and S. eridania. However, S. frugiperda had higher survival on this Bt soybean, and Cry1Ac soybean showed low lethality against all species evaluated. Spodoptera larvae that survived on Bt and non-Bt soybean showed comparable susceptibility to flubendiamide and thiodicarb in diet-overlay bioassays. Regardless of soybean plant type, the field doses of flubendiamide and thiodicarb were effective in controlling surviving Spodoptera larvae. We conclude that Cry1A.105/Cry2Ab2/Cry1Ac soybean is effective in controlling S. cosmioides and S. albula, and also has reasonable control of S. eridania, but not S. frugiperda. Cry1Ac soybean provided poor control of all Spodoptera species. Nonetheless, Spodoptera larvae surviving on both Bt and non-Bt soybean were controlled by flubendiamide and thiodicarb. Thus, integrated control tactics would provide effective management of Spodoptera species in Bt soybean fields in South America. Full article

Tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is the major pest of tomato crops in Pakistan. Insecticides are commonly used for the management of this insect-pest. To develop a better insecticide resistance management strategy and evaluate the risk of resistance evolution, a field collected population of the tomato pinworm was selected with flubendiamide in the laboratory. We investigated the genetics of flubendiamide resistance and concentration-mortality response to other insecticides by selecting a field strain of tomato pinworm with commercial flubendiamide formulation. Tuta absoluta was reciprocally crossed with resistant strain (Fluben-R) and was selected up to 13 generations, while F₁ progeny was back-crossed with resistant parent (Fluben-R). The results of LC₅₀ and Resistance Ratio (RR) demonstrated a higher resistance developed in field and laboratory-selected strains (G₂ and G₁₃, respectively). Field-collected and laboratory-selected (Fluben-R) strains demonstrated higher intensity of concentration-mortality response against chlorantraniliprole, thiamethoxam, permethrin, abamectin and tebufenozide compared to susceptible ones. Based on the overlapping of 95% FL, it demonstrated significant differences, revealing that it was not sex linked (autosomal) with no maternal effects. The backcross analysis of the F₁× resistant parent resulting in significant differences at all concentrations suggests that resistance is controlled by more than one factor; the null hypothesis was rejected and inheritance was under polygenic control. Resistance progression from 38 to 550 folds demonstrated that T. absoluta can develop a higher level of resistance to flubendiamide. Concentration-mortality response experiments demonstrated that the LC₅₀ of some tested insecticides was higher for field-collected and laboratory-selected strains, suggesting that resistance mechanisms should be studied at a molecular level for better understanding. These results could be helpful to design resistance management strategies against the tomato pinworm. Full article

The marked adoption of bioinsecticides in Brazilian agriculture in recent years is, at least partially, explained by the increasingly higher levels of insect pest resistance to synthetic insecticides. In particular, several baculovirus-based products have been registered in the last 5 years, including Helicoverpa armigera nucleopolyhedrovirus (HearNPV: Baculoviridae: Alphabaculovirus (Armigen^®)). Understanding the susceptibility of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) to HearNPV is an important step toward development of robust Integrated Pest Management (IPM) and Insect Resistance Management programs (IRM) aimed at managing this serious insect pest. In this study, droplet feeding bioassays were used to characterize the baseline susceptibility to HearNPV (Armigen^®) in H. armigera populations collected from major soybean and cotton-growing regions in Brazil. We defined and validated a diagnostic concentration for susceptibility monitoring of H. armigera populations to HearNPV. Additionally, cross-resistance between HearNPV and the insecticides flubendiamide and indoxacarb was evaluated by testing HearNPV in a susceptible strain and in resistant strains of H. armigera to these insecticides. A low interpopulation variation of H. armigera to HearNPV was detected. The LC₅₀ values ranged from 1.5 × 10⁵ to 1.1 × 10⁶ occlusion bodies (OBs) per mL (7.3-fold variation). The mortality rate at the identified diagnostic concentration of 6.3 × 10⁸ OBs/mL, based on the calculated LC₉₉, ranged from 98.6 to 100% in populations of H. armigera collected from 2018 to 2020. No cross-resistance was detected between HearNPV and flubendiamide or indoxacarb. These results suggest that HearNPV (Armigen^®) can be an effective tool in IPM and IRM programs to control H. armigera in Brazil. Full article

Fall armyworm (FAW), Spodoptera frugiperda, is an important lepidopteran pest in the Americas, and recently invaded the Eastern Hemisphere. In Brazil, FAW is considered the most destructive pest of corn and cotton. FAW has evolved resistance to many insecticides and Bacillus thuringiensis (Bt) proteins. Here, a large-scale monitoring was performed between 2019 and 2021 to assess diamide insecticide susceptibility in more than 65 FAW populations sampled in corn and cotton. We did not detect a significant shift in FAW susceptibility to flubendiamide, but a few populations were less affected by a discriminating rate. F2 screen results of 31 selected FAW populations across regions confirmed that the frequency of diamide resistance alleles remained rather stable. Two laboratory-selected strains exhibited high resistance ratios against flubendiamide, and cross-resistance to anthranilic diamides. Reciprocal crosses indicated that resistance is autosomal and (incompletely) recessive in both strains. F1 backcrosses suggested monogenic resistance, supported by the identification of an I4734M/K target-site mutation in the ryanodine receptor (RyR). Subsequent genotyping of field-collected samples employing a TaqMan-based allelic discrimination assay, revealed a low frequency of RyR I4790M/K mutations significantly correlated with phenotypic diamide resistance. Our findings will help to sustainably employ diamides in FAW resistance management strategies across crops. Full article

The cotton bollworm Helicoverpa armigera (Lepidoptera: Noctuidae) is a significant pest in the world and it was identified in Brazil in 2013, causing severe economic losses. Recent studies showed a significant decrease in the susceptibility of H. armigera to diamide insecticides in Brazil. Understanding the genetic basis and mechanisms of the resistance are essential to develop proactive resistance management strategies. A laboratory strain of H. armigera resistant to the phthalic acid diamide flubendiamide (Flub-R) was selected from a field-collected population to characterize the resistance. The resistance ratio of the Flub-R strain was >50,000-fold. The inheritance pattern of the resistance was characterized as an autosomal dominant trait. Flub-R showed no cross-resistance to the anthranilic diamides chlorantraniliprole, cyantraniliprole or cyclaniliprole. Susceptible strain larvae that fed on flubendiamide-treated soybean leaves at field-recommended rates were killed while heterozygotes and Flub-R larvae showed a high survival and no reduction in the leaf consumption, confirming the functional dominance of the resistance. No indication of metabolic resistance was detected. The partial sequencing of ryanodine receptor (RyR) genes covering the transmembrane II to VI did not show any amino acid mutations, indicating the presence of a non-common resistance mechanism to diamide insecticides in the Flub-R strain. Full article

Alterations to amino acid residues G4946 and I4790, associated with resistance to diamide insecticides, suggests a location of diamide interaction within the pVSD voltage sensor-like domain of the insect ryanodine receptor (RyR). To further delineate the interaction site(s), targeted alterations were made within the same pVSD region on the diamondback moth (Plutella xylostella) RyR channel. The editing of five amino acid positions to match those found in the diamide insensitive skeletal RyR1 of humans (hRyR1) in order to generate a human–Plutella chimeric construct showed that these alterations strongly reduce diamide efficacy when introduced in combination but cause only minor reductions when introduced individually. It is concluded that the sites of diamide interaction on insect RyRs lie proximal to the voltage sensor-like domain of the RyR and that the main site of interaction is at residues K4700, Y4701, I4790 and S4919 in the S1 to S4 transmembrane domains. Full article