Work

Methomyl resistance in Dalbulus maidis (Hemiptera: Cicadellidae): selection, inheritance and multiple‐resistance

Year: 2026

Type: article

Abstract: BACKGROUND: Acetylcholinesterase (AChE) inhibitor insecticides have been important tools for the management of Dalbulus maidis in Brazil; however, the selection pressure exerted by their extensive use has led to reduced susceptibility in field populations, particularly to the carbamate methomyl. To implement resistance management strategies for D. maidis resistance to methomyl, we selected a methomyl-resistant strain (Methomyl-R) from a field population of D. maidis collected from Goiás State to characterize the inheritance patterns and potential cross- or multiple-resistance to other insecticides. RESULTS: of the susceptible reference strain (SUS), increased from 9.73- to 163.42-fold over 26 generations of selection pressure. Conversely, the unselected strain (RV-Unsel) derived from the same field population decreased the RR from 9.73- to 4.09-fold after 28 generations. The reciprocal crosses between Methomyl-R and SUS indicated that resistance of D. maidis to methomyl is autosomal and incompletely dominant. Backcrosses between heterozygous strains and SUS suggested a polygenic architecture. Low cross-resistance was observed to the AChE inhibitors carbosulfan (5.63-fold) and acephate (8.93-fold), as well as to buprofezin (≈ 10-fold). High RRs were observed for neonicotinoids and pyrethroids (> 50-fold). No cross-resistance was detected for chlorfenapyr, cyantraniliprole or isocycloseram (< 5-fold). CONCLUSION: The incompletely dominant inheritance of methomyl resistance may contribute to a high risk of resistance-associated control failure in D. maidis. Insecticides from different chemical groups including chlorfenapyr, cyantraniliprole and isocycloseram were identified as viable candidates for resistance management programs of D. maidis to methomyl. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Source: Pest Management Science

DOI: 10.1002/ps.71254

Authors: Matheus Gerage Sacilotto, Gabriel Silva Dias, Mariana Yuki Iuanami, Celso Omoto

Institution: Universidade de São Paulo

Language: English

Topic: Insect Resistance and Genetics

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

SDG: Zero hunger

Open Access status: hybrid

Estimated APC paid: $5,360