Affiliation:
1. College of Plant Protection Yangzhou University Yangzhou China
2. College of Plant Protection Hunan Agricultural University Changsha China
3. Jiangsu Co‐Innovation Center for Modern Production Technology of Grain Crops Yangzhou University Yangzhou China
Abstract
AbstractThe predatory bug Cyrtorhinus lividipennis Reuter (Hemiptera: Miridae) is an important biological control agent for planthoppers, such as Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), and leafhoppers in rice fields (Oryza sativa L., Poaceae). In this study, the sublethal effects of azoxystrobin and difenoconazole, two fungicides extensively used in rice production, on this predatory bug were investigated. The results indicated that exposure to the two fungicides at the third instar had no influence on developmental duration, but difenoconazole resulted in a 25.2% decrease in the lifespan of adult males. When exposed as newly emerged adults, azoxystrobin caused a 33.5% decrease in female longevity. The pre‐oviposition period of azoxystrobin‐treated females mating with azoxystrobin‐treated males was shortened by 44.9%, compared with the control, whereas the pre‐oviposition period of difenoconazole‐treated females mating with control males was lengthened by 32.2% compared with the control group. However, the two fungicides had no effect on fecundity and egg hatchability. Furthermore, the two fungicides did not impact the average consumption of C. lividipennis of N. lugens individuals. They did stimulate the response of C. lividipennis males to rice plants infested by N. lugens in a two‐choice H‐shaped olfactometer test. Also, the predatory capacity of C. lividipennis males was increased after exposure to difenoconazole, whereas the predatory capacity of females was decreased after exposure to the two fungicides. Overall, our results indicated that azoxystrobin and difenoconazole pose no notable risk to C. lividipennis. These findings establish a foundation for the rational and coordinated utilization of fungicides and biological control agents in rice ecosystems.
Funder
National Natural Science Foundation of China
National Key Research and Development Program of China