›› 2002, Vol. 45 ›› Issue (4): 494-498.

• RESEARCH PAPERS • Previous Articles     Next Articles

Diversity in life history of the leaf beetle, Colaphellus bowringi Baly

XUE Fang-Sen1, LI Ai-Qing1,ZHU Xing-Fen1, GUI Ai-Li1,JIANG Pei-Lan1, LIU Xiao-Fen2   

  • Online:2002-08-20 Published:2002-08-20

Abstract: The leaf beetle, Colaphellus bowringi Baly is a serious pest of crucifers in mountain areas of Jiangxi Province, aestivating and hibernating as adults in the soil. The beetle showed considerable intrapopulation variation in its life history due to the differences in the duration of diapause. Some individuals took more than one year to produce one generation. Some were univoltine, i.e., only one generation in spring or autumn; some were biovoltine, i.e., one generation in spring and another in autumn; and some were multivoltine, i.e., one generation in spring and two or three generations in autumn. Thus, there could be up to four generations per year in the field. In spring, diapausing adults began to appear from the soil one after another from late February to early April. In autumn, diapausing adults appeared in succession from mid-August to early October. Newly emerged adults of the spring generation began to burrow into soil for dormancy between the end of April and early June. Adults of the autumn generation began to enter diapause from midSeptember to the end of December. Adult beetles could mate many times during their reproductive period. The egg-laying period of most females exceeded one month, the longest being 67 days. An average individual female could produce 644 eggs in the spring generation, 963 eggs in the autumn generation, the most being 1 950 eggs. Between 15 and 30℃, developmental duration was 13.78-3.14 days in the egg stage, 22.83-6.95 days in the larval stage, and 12.10-3.18 days in the pupal stage. Developmental thresholds were 10.7℃ for egg, 8.8℃ for larva and 9.6℃ for pupae. Non-diapausing adults had a life span of about 1-2 months. The life span of diapausing adults ranged from 5 to 38 months. All aestivating and hibernating adults displayed digging behavior and burrowed in soil to depths of 9-31 cm.

Key words: Colaphellus bowringi, diversity of life history, voltinism, aestivation, hibernation