关键词: 莲草直胸跳甲, 生殖系统, 卵巢发育, 繁殖, 生物防治

Abstract: In order to identify organs and behavior closely related to reproduction, observations on reproductive system and reproductive biology of the alligatorweed flea beetle, Agasicles hygrophila were conducted in the laboratory. The results showed that the female adult have 2 ovaries, each of which contains 12-16 telotrophic ovarioles, spermatheca is in the shape of bean sprout, and the aedeagus is fork-type. Ovarian development can be divided into 5 grades based on the morphological characteristics of ovaries: stage Ⅰ (No oocyte stage), stage Ⅱ (Previtellogenic stage), stage Ⅲ (Egg maturation stage), stage Ⅳ (Ovipositing stage), and stage Ⅴ (Post-oviposition stage). Each stage shows significant differences in the length of ovarian zones and egg-carrying number. In addition, the beetles could mate around 2 d after emergence, a copulation peak appears on 16：00-18：00, the oviposition peak occurrs on 12：00-16：00, and the beetles prefer to the blade back of leaf in the middle stratum of host. Temperature had a significant effect on longevity and fecundity. Female longevity and fecundity decreased with increasing of the temperature within 22-32℃, and temperatures below 22℃ or above 32℃ were unfavorable for ovarian development. At 32℃, the pre-oviposition period extended to 7.2 d, while the longevity and fecundity decreased significantly. Therefore, it is inferred that high and constant temperature above 32℃ is a possible cause for the population decay of the alligatorweed flea beetle in summer.

Key words: Agasicles hygrophila, reproductive system, ovarian development, reproduction, biological control