Feeding behavior and hormoligosis associated with imidacloprid resistance in Asian citrus psyllid, Diaphorina citri

Xue Dong Chen; Justin George; Lauren M Diepenbrock; Hunter Gossett; Guoping Liu; Jawwad A Qureshi; Lukasz L Stelinski

doi:10.1111/1744-7917.13293

Feeding behavior and hormoligosis associated with imidacloprid resistance in Asian citrus psyllid, Diaphorina citri

Insect Sci. 2023 Nov 15. doi: 10.1111/1744-7917.13293. Online ahead of print.

Authors

Xue Dong Chen^{1

2}, Justin George³, Lauren M Diepenbrock¹, Hunter Gossett¹, Guoping Liu¹, Jawwad A Qureshi², Lukasz L Stelinski¹

Affiliations

¹ Entomology and Nematology Department, University of Florida, Citrus Research and Education Center, Lake Alfred, Florida, USA.
² Entomology and Nematology Department, University of Florida, Southwest Florida Research and Education Center, Immokalee, Florida, USA.
³ Southern Insect Management Research Unit, USDA-ARS, Stoneville, Mississippi, USA.

PMID: 37969015
DOI: 10.1111/1744-7917.13293

Abstract

Imidacloprid is a neonicotinoid insecticide used for managing the Asian citrus psyllid, Diaphorina citri Kuwayama, which serves as vector of phytopathogens causing citrus greening. However, development of resistance to neonicotinoids among populations of D. citri has coincided with occasional control failures in the field. The objectives of this research were to (1) survey current levels of imidacloprid resistance in Florida citrus; (2) compare feeding behavior between imidacloprid-resistant and susceptible D. citri using electrical penetration graph recordings, and (3) investigate the possible amplification of insecticide hormoligosis associated with resistance. Field surveys confirmed that the susceptibility of D. citri populations to imidacloprid has decreased in commercial Florida citrus groves compared with a laboratory-susceptible population. Following 12 generations of selection, resistance to imidacloprid increased by 438 fold compared with the susceptible strain. Imidacloprid-susceptible D. citri feeding on citrus exhibited significantly more bouts associated with intercellular pathway (C), phloem penetration (D), phloem salivation (E1), and nonprobing (Np) activities than imidacloprid-resistant counterparts. However, there were no differences observed in the frequency or duration of phloem ingestion or xylem feeding between susceptible and resistant D. citri. There was no statistical difference in fecundity between resistant and susceptible strains. However, the fecundity of imidacloprid-susceptible female D. citri treated with a sublethal concentration of imidacloprid (LC₂₅ ) increased significantly compared with controls, while such hormoligosis was less pronounced among imidacloprid-resistant psyllids. Our results suggest that imidacloprid-resistant psyllids may cease feeding sooner than susceptible counterparts following sublethal exposure to this insecticide, indicative of a behavioral resistance mechanism.

Keywords: artificial selection; electrical penetration graph; feeding behavior; hormoligosis; insecticide resistance; sublethal exposure.

Abstract

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