A STUDY OF THE BIOLOGICAL TRAITS OFAPATELE MAJOR BREMER

Wu Kaiming Zhang Yuansong Wang Zhiwen Li Chuanfang(Sericulture and Silk College,Southwest Agricultural University,Chongqing 400716,China )

Apatele major Bremer Biological traits

Indoor feeding experiment combined with field observation carried out at Southwest A-gricultural Univevsity showed that two generations of Apatele major Bremer, a pest insectwhich has brought great losses to mulberry crops in Chongqing,occurred in a year and the hi-bernated pupae started to emerge in mid - May. In the first generation the egg,larval and pu-pation stages lasted 3. 9, 21. 2 (at 25. 99℃) and 61. 5 days, respectively, and the life span ofthe adult varied from 5 to 7 days. The peak of larval occurrence appeared form mid - May tomid - June. Mulberry leaf consumption by each larva averaged 9234. 73mg before the pupa-tion of 6 - instar larvae. The stage of emergence was from late August to early September.The average yield of eggs per female was 447 grains with a female: male ratio of 1∶1. 48.The larval occurrence of the second generation started from late August and lasted to the endof November,with a peak appearing in mid - October to mid - November. The duration of thelarval stage covering all instars averaged 46. 22 days (at 17. 48℃). Mulberry leaf ingestion byeach larva was similar to that of the first generation. Pupation occurred primarily in Novem-ber,when the temperature was relatively low.