Assessment of molecular and biochemical resistance mechanisms in soybean looper (Chrysodeixis includens) to diamide insecticides

Author

Sena Isbilir, Mississippi State UniversityFollow

ORCID

https://orcid.org/0009-0003-8103-3399

Issuing Body

Mississippi State University

Advisor

Ahn, Seung-Joon

Committee Member

Musser, Fred R.

Committee Member

Krishanan, Krish

Committee Member

Rai, Aswathy

Date of Degree

12-13-2024

Original embargo terms

Complete embargo 2 years

Document Type

Dissertation - Open Access

Major

Life Sciences (Entomology)

Degree Name

Doctor of Philosophy (Ph.D.)

College

College of Agriculture and Life Sciences

Department

Department of Agricultural Science and Plant Protection

Abstract

Diamides selectively modulate insect ryanodine receptors (RyRs) and homotetrameric calcium (Ca2+) channels in the sarcoplasmic and endoplasmic reticulum. Diamides were introduced to the insecticide market approximately 17 years ago, primarily used for lepidopteran pest management. They are known for their high efficacy and target specificity and are used globally. However, as of 2023, diamide resistance has been reported in at least 17 countries and 16 pest species, including soybean looper (Chrysodeixis includens). Soybean looper is a migratory pest of soybeans and is accountable for around 13% of the total loss in soybeans in Mississippi. This study examined resistance mechanisms in soybean looper to chlorantraniliprole (CHL), a commonly used diamide insecticide. A soybean looper population from Puerto Rico conferring mild resistance to CHL (RR=10) was studied, and that population contained a RyR mutation, namely Y4667C, associated with diamide insecticide, Y4667C, with 61% mutation frequency. The function of the mutation in CHL resistance has been studied, and further experiments are being conducted. The contribution of metabolic resistance mechanisms to the observed resistance was also assessed by applying RNA-seq. According to RNA-seq and qRT-PCR verification analysis, CYP4 may be involved in CHL resistance in soybean looper. Therefore, based on these findings, both target site and metabolic resistance mechanisms appear to provide moderate levels of CHL resistance in soybean looper. However, further studies, which are in progress, are needed to confirm this conclusion.

Recommended Citation

Isbilir, Sena, "Assessment of molecular and biochemical resistance mechanisms in soybean looper (Chrysodeixis includens) to diamide insecticides" (2024). Theses and Dissertations. 6440.
https://scholarsjunction.msstate.edu/td/6440