Effects of Temperature on Functional Response of Anagrus nilaparvatae Pang et Wang (Hymenoptera: Mymaridae) on the Eggs of Whitebacked Planthopper, Sogatella furcifera Horváth and Brown Planthopper, Nilaparvata lugens Stål

Understanding the temperature affecting parasitic efficiency is critical to succeed in utilizing parasitoid as natural enemy in pest management. Laboratory studies were carried out to determine the effects of temperature on parasitoid preference of female Anagrus nilaparvatae Pang et Wang (Hymenoptera: Mymaridae) to the eggs of whitebacked planthopper (WBPH), Sogatella furcifera Horváth and brown planthopper (BPH), Nilaparvata lugens Stål to build a composite model describing changes in parasitic response along a temperature gradient (18, 22, 26, 30, 34C). The results showed that attack responses of A. nilaparvatae on WBPH and BPH were the best described by a Type II functional response. The two parameters, attack rates (a) and handling times (Th), of A. nilaparvatae to both eggs were influenced by the temperature. The maximum attack rates to WBPH (1.235) and BPH (1.049) were at 26 and 34C, respectively, and the shortest handling times to WBPH (0.063) and BPH (0.057) were at 30 and 26C, respectively. However, the optimal temperature for parasitic efficiency of A. nilaparvatae to WBPH and BPH eggs was both at 26C, which showed that the present microclimate temperature of the habitat in the paddyfield was beneficial to A. nilaparvatae and indicated that parasitic efficiency of A. nilaparvatae would be impaired by global warming.