BACKGROUND: Cyantraniliprole, a diamide insecticide, is widely used in Brazil to control sucking and defoliating pests, including the fall armyworm (Spodoptera frugiperda), a major agricultural pest. However, increasing resistance to diamides has raised concerns about the long‐term effectiveness of cyantraniliprole. This study aimed to (i) assess the evolution of cyantraniliprole resistance in field populations of S. frugiperda, (ii) investigate cross‐resistance to other diamides, and (iii) analyze the role of the I4790K mutation in resistance mechanisms.RESULTS: A significant decrease in the susceptibility to cyantraniliprole was observed in field populations of S. frugiperda in Brazil, particularly in regions with intensive agricultural systems, such as the Brazilian Cerrado, from 2017 to 2023. A cyantraniliprole‐resistant strain of S. frugiperda was selected from a field‐collected population in Bahia (BA) using the F₂ screening method. The inheritance of resistance to cyantraniliprole in this strain was autosomal recessive and monogenic, with 3414‐fold resistance ratio. High cross‐resistance to the diamides flubendiamide, chlorantraniliprole, and cyclaniliprole was also detected. Molecular analysis confirmed the presence of the homozygous I4790K mutation in the ryanodine receptor gene as one of resistance mechanisms of this cyantraniliprole‐resistant strain.CONCLUSION: These findings highlight the decreased susceptibility of field populations of S. frugiperda to cyantraniliprole and the role of the I4790K mutation in accelerating the evolution of resistance to diamide insecticides due to cross‐resistance. These results underscore the urgent need for integrated pest management (IPM) strategies, including insecticide rotation and resistance monitoring, to preserve the efficacy of cyantraniliprole and other insecticides. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Monitoring Tetranychus urticae Koch in cotton crops is challenging due to the vast crop areas and clustered mite attacks, hindering early infestation detection. Hyperspectral imaging offers a solution to such a challenge by capturing detailed spectral information for more accurate pest detection. This study evaluated machine learning models for classifying T. urticae infestation levels in cotton using proximal hyperspectral remote sensing. Leaf reflection data were collected over 21 days, covering various infestation levels: no infestation (0 mites/leaf), low (1–10), medium (11–30), and high (>30). Data were preprocessed, and spectral bands were selected to train six machine learning models, including Random Forest (RF), Principal Component Analysis–Linear Discriminant Analysis (PCA-LDA), Feedforward Neural Network (FNN), Support Vector Machine (SVM), k-Nearest Neighbor (kNN), and Partial Least Squares (PLS). Our analysis identified 31 out of 281 wavelengths in the near-infrared (NIR) region (817–941 nm) that achieved accuracies between 80% and 100% across 21 assessment days using Random Forest and Feedforward Neural Network models to distinguish infestation levels. The PCA loadings highlighted 907.69 nm as the most significant wavelength for differentiating levels of two-spotted mite infestation. These findings are significant for developing novel monitoring methodologies for T. urticae in cotton, offering insights for early detection, potential cost savings in cotton production, and the validation of the spectral signature of T. urticae damage, thus enabling more efficient monitoring methods.

Huanglongbing (HLB), the most serious disease in citriculture, is caused by the bacteria Candidatus Liberibacter spp., which is transmitted by the Asian citrus psyllid (ACP) Diaphorina citri. HLB is mainly controlled with insecticides, necessitating the development of alternative methods, e.g., the use of trap plants such as curry leaf Bergera koenigii, which is highly attractive to the ACP. We evaluated the effects of the main systemic insecticides used by citrus growers, applied via drench to adults of D. citri on the curry leaf tree. We tested the persistence of three pesticides: thiamethoxam, thiamethoxam + chlorantraniliprole, and imidacloprid in protected cultivation and the field condition at 7, 14, 28, 42, 56, 70, 98, and 154 days after the application. Different concentrations of insecticides containing the active ingredient thiamethoxam were tested on adults to determine the LC₁₀ and LC₅₀. Finally, we assessed the sublethal effects on the oviposition and development of D. citri. The insecticides controlled the adults for long periods. However, in the field experiment, from 42 days after application there was a decrease in mortality caused by pesticides applied via drench, while in the protected cultivation, mortality did not decline until the last day of evaluation. The median lethal concentration (LC₅₀) for thiamethoxam was 0.031 g of active ingredient per plant, and for thiamethoxam in a mixture, the LC₅₀ was 0.028 g a.i. per plant. In the experiment with sublethal doses, D. citri did not oviposit on the treated plants. Our findings suggest that the attract-and-kill system using the curry leaf tree and systemic insecticides is effective for the control of D. citri and contributes to the integrated management of HLB.

This study investigated the lethal and transgenerational effects of botanical and synthetic insecticides on the egg parasitoid Trichogramma atopovirilia, an important natural enemy of Spodoptera frugiperda in Brazil and beyond. The treatments were assessed for their impact on parasitism, emergence, sex ratio, and flight capacity of adults exposed to contaminated eggs. The botanical insecticide ESAM (ethanolic seed extract of Annona mucosa) significantly reduced the parasitism in the F0 generation by 99.76%, categorizing it as toxic. Anosom® [acetogenins (annonin as a major component)] and Azamax® [limonoids (azadirachtin + 3-tigloilazadirachtol)] also caused substantial reductions (99.13% and 92.36%, respectively) in the parasitism rate. EFAMON (ethanolic leaf extract of Annona montana) reduced the parasitism by 62%, while the synthetic insecticide Premio® (chlorantraniliprole) resulted in a 28.21% reduction. In the F1 generation, emergence rates for EFAMON, Azamax®, and Premio® exceeded 70%, showing no significant differences from the negative control (82%), while Anosom® resulted in a lower emergence rate of 61.39%. No significant effects were observed on sex ratio or parasitism in the F1 and F2 generations. Most adults reached high flight capacity (above 80%). These results indicate that while ESAM was toxic, the other treatments showed no transgenerational effects. Our findings contribute to understanding insecticide selectivity and highlight the importance of such studies for the sustainable management of S. frugiperda within integrated pest management programs.

BACKGROUND: Pyrethroid insecticides have been a primary strategy for managing Dalbulus maidis (Hemiptera: Cicadellidae) in Brazil. Howeve, failures in the control of D. maidis with pyrethroids have been reported. In this study, we selected a bifenthrin‐resistant strain of D. maidis under laboratory cage conditions to investigate the inheritance pattern of resistance, cross‐resistance to other insecticides, and resistance stability.RESULTS: The estimated LC₅₀ of the Bif‐R was 2,055.72 μg a.i. mL⁻¹, while that of the susceptible (Sus) strain was 0.64 μg a.i. mL⁻¹, resulting in a 3,170‐fold resistance ratio (RR). Reciprocal crosses (H1: Bif‐R ♀ × Sus ♂ and H2: Bif‐R ♂ × Sus ♀) and backcrosses between heterozygous H1 and H2 with the Sus strain indicated autosomal, incompletely dominant, and polygenic resistance. Potential cross or multiple‐resistance was observed between Bif‐R and lambda‐cyhalothrin, imidacloprid, and acetamiprid, with resistance ratios varying from 300‐ to 2,000‐fold. No cross‐resistance was detected between Bif‐R and methomyl, carbosulfan or acephate. Cage studies with different proportions of Sus and Bif‐R strains revealed that resistance of D. maidis to bifenthrin is unstable. A decrease in the LC₅₀ of the field‐collected population from 113.61 to 10.73 μg bifenthrin mL⁻¹ was detected in the absence of selection pressure.CONCLUSIONS: Our findings provide insights into the evolution of resistance of D. maidis to bifenthrin. This study is the first comprehensive analysis of pyrethroid resistance in D. maidis and will contribute to insect resistance management (IRM) strategies to preserve the efficacy of bifenthrin and other insecticides. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Emamectin benzoate has been largely used for controling lepidopterans larvae in grains and fiber crops and, therefore, selection of resistant populations to this pesticide is a real risk if ignored the insect resistance management (IRM) strategies. We studied the susceptibility of Spodoptera frugiperda (Smith, 1797) populations in the state of Mato Grosso - Brazil to Emamectin benzoate as well as a field study about Mode of Action rotation including this compound. Low variations in susceptibility (resistance ratios, 1,01-7,31 fold) were detected among the evalueted S. frugiperda populations. The field study reinforced our monitorings outcome that Emamectin Benzoate controls S. frugiperda and its use in IRM in Mato Grosso is practicable. Susceptibility monitoring should be continuous in order to detect possible increases of tolerance rates not only for this pesticide but also for all compounds used for this pest management aiming to apply early mitigation actions.