Serangium japonicum Chapin and Delphastus catalinae Horn are important natural enemies of Bemisia tabaci . The biological characteristics of S. japonicum including life history, feeding behaviour, pupation, mating, oviposition, longevity of adults and the comparative morphology of the two kinds of coccinellids were studied. The results were as follows: S. japonicum developed 6-7 generations a year in Fujian Province and it overwintered in the form of adult; developmental times for eggs, 1st, 2...