稻虱缨小蜂耐热品系的生物和生态学特征

稻虱缨小蜂Anagrus nilaparvatae Pang et Wang是控制稻飞虱种群暴发的主要寄生性天敌之一,高温是制约其种群动态的重要因子.为了解35℃高温驯化获得的稻虱缨小蜂耐热品系(NR品系)的生防潜力,对不同温度下该品系的发育历期、有效积温、寄主卵选择、产卵量以及极端高温胁迫参数进行了测定.结果发现,与...

Biological and Ecological Characteristics of a Thermotolerant Strain of Anagrus nilaparvatae

The parasitoid, Anagrus nilaparvatae Pang et Wang, is one of the major natural enemies of rice planthoppers, while its population dynamics are frequently subjected to the restriction of high temperature. In this study, we measured the developmental duration, effective accumulative temperature, host egg preference, oviposition amount, and stress response parameters at extremely high temperatures of a thermotolerant strain of A. nilaparvatae (NR strain, acclimated at 35℃ for 24 generations) to characterize its biocontrol potential. The results showed that, compared with the A. nilaparvatae control strain HZ, males of the NR strain showed a significantly higher development rate at 20℃, and the difference was mainly due to the egg-middle larvae stage and the pupal stage. NR strain oviposited even at high temperatures, with 18.80 eggs per female at 35℃. NR strain showed higher tolerance to extreme temperatures than HZ strain. The heat knockdown time of NR strain males at 50℃ was 15.19 min, 3.03 min longer than that of the HZ strain. Furthermore, the fecundity of NR strain was affected by nutriments. Supplement of 10% sucrose at 35℃ could not only prolong lifespan but also increase fecundity. Those results indicate that the A. nilaparvatae strain acclimated at high temperatures can maintain normal growth and parasitism at 35℃, which confers its potential to adapt to high temperatures in summer.