Original paper
An octopamine receptor involved in feeding behavior of the two-spotted spider mite, Tetranychus urticae Koch: a possible candidate for RNAi-based pest control
Hamdi, Faten Abdelsalam; Kataoka, Kosuke; Arai, Yuka; Takeda, Naoki; Yamamoto, Masanobu; Mohammad, Yasser F. O.; Ghazy, Noureldin Abuelfadl; Suzuki, Takeshi
Entomologia Generalis Volume 43 Number 1 (2023), p. 89 - 97
published: Mar 22, 2023
published online: Feb 9, 2023
manuscript accepted: Dec 26, 2022
manuscript revision received: Dec 23, 2022
manuscript revision requested: Nov 8, 2022
manuscript received: Aug 28, 2022
DOI: 10.1127/entomologia/2023/1808
Open Access (paper may be downloaded free of charge)
Abstract
The two-spotted spider mite (TSSM), Tetranychus urticae Koch (Acari: Tetranychidae), is an agricultural pest distributed almost worldwide. Because of the frequent use of synthetic pesticides for its control, it has developed resistance to almost all types of active ingredients, making its chemical control very difficult. RNA interference (RNAi) is a sequence-specific gene silencing process triggered by double-stranded RNA (dsRNA). Since RNAi is induced in TSSM by orally ingested dsRNA, the use of dsRNA with sequences specific to essential genes in TSSM has potential as an alternative to synthetic pesticides. Here, we evaluated the effects of RNAi targeting the TSSM gene encoding a β-adrenergic-like octopamine receptor (TuOctβ2R), a target of the synthetic pesticide amitraz, by oral administration of dsRNA for the gene (dsTuOctβ2R). Survival and fecundity rates and feeding activity in mites fed on dsTuOctβ2R were significantly lower than those in a control group fed on dsRNA targeting an intergenic region, even in an amitraz-resistant population. Mites fed on dsTuOctβ2R moved significantly faster than the controls, suggesting that downregulation of TuOctβ2R induces hyperactivity while suppressing feeding behavior. These results indicate that the TuOctβ2R gene is a possible candidate for RNAi-based biopesticides to control TSSM.
Keywords
amitraz • dsRNA • locomotion • oral administration • pesticide resistance