Effects of temperature on fitness costs in chlorpyrifos-resistant brown planthopper, Nilap

Effects of temperature on fitness costs in chlorpyrifos-resistant brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae)

Bao-Jun Yang;Mei-Ling Liu;Yi-Xi Zhang;Ze-Wen Liu

【期刊名称】《中国昆虫科学：英文版》 【年(卷),期】2018(025)003

【摘要】Insecticide resistance is inevitable if an insecticide is widely used to control insect pests.Fortunately,the resistance-associated fitness costs often give chances to manage resistances.In most cases,the fitness cost in resistant insects is often evaluated under laboratory conditions for insect development,which limits its practical application in pest control in the field.In a laboratory population R9 with 253-fold resistance to chlorpyrifos after nine-generation selection with chlorpyrifos,the relative fitness was only 0.206 under laboratory conditions (25℃,humidity 70％-80％ and 16 h light/8 h dark photoperiod),when

compared

to

S9,a

susceptible

counterpart

(resistance ratio =2.25-fold) from the same origin as R9 but without any selection with insecticides.Temperatures varied the resistance-associated fitness costs,with enhanced costs at high temperatures and reduced costs at low temperatures,such as 0.174 at 32℃ and 0.527 at 18℃.The copulation rate and fecundity were two key factors for the reduced costs at low temperatures.Another finding was that R9