Biology of Pachyneuron aphidis-the Hyperparasitoid of Myzus persicae

It was observed that it took 10 to 12 days for Pachyneuron aphidis to complete its life circle under the conditions of 25 ±1℃ in temperature and 70%~80%of RH.The sex ratio was 1.9 ♀:1.0 ♂.The female adults of Pachyneuron aphidis mated and oviposited within 24 hours after emergence.The male adults were capable of mating for several times, whereas the female adults could mate only once.The unmated females could only produce male progeny by parthenogenesis.Each female adult oviposited 162 to 335 eggs, and the average amount was 223.7.The amount of oviposition would increase along with the lengthening of females' lifespan.The duration of the female adults of Pachyneuron aphidis to parasite on the Myzus persicae could last for 24 days and the highest hyperparasitic rate could reach 37.86% in the tobacco field.The largest population of Pachyneuron aphidis occurred only 5 days behind that of Aphidius gifuensis and it was believed that Pachyneuron aphidis was an important factor to limit the population of Myzus persicae.