The biological characteristics of the Longnan (24°9′ N, 114°8′ E) population of Colaphellus bowringi Baly (Coleoptera:Chrysomelidae) were systematically investigated. This beetle has two distinct infestation peaks in the field, one in spring and the other in autumn,aestivating and hibernating as adults in the soil. Life history differs because of adults' various diapause duration. 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 bivoltine, 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 were one to four generations per year in the field. In spring, diapaused adults began to appear from the soil one after another from midFebruary to early April. New emerged adults of the spring generation began to burrow into soil for dormancy between the early April and midMay. In autumn, diapaused adults appearedin succession from midAugust to midOctober. Adults of autumn generation began to enter diapause from midSeptember to midDecember. Adults could mate many times during their reproductive period. Under 25℃, the egglaying period of most female lasts for 8-29 d in the spring generation and 9-39 d in the autumn generation. On average one female could produce 776 eggs in the spring generation and 1 003 eggs in the autumn generation. Between 18 and 28 ℃, developmental duration was 8.66～3.85 d days in the egg stage, 19.37-7.92 d days in the larval stage, and 8.57～3.41 d days in the pupal stage. Developmental thresholds were 10.5℃ for egg, 11.5℃ for larva and 11.9℃ for pupae respectively. The life span of diapaused adults ranged from 5 to 28 months. 

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