浙江省马尾松毛虫的赤眼蜂种类调查及用柞蚕卵繁蜂对优势种的影响

1988～1989年在浙江省11个县(市)作马尾松毛虫卵期赤眼蜂抽样调查,经雄蜂外生殖器鉴别,明确有松毛虫赤眼蜂和拟澳洲赤眼蜂2种,1988年全年林间调查,二者分别占样本总数的86.85％和13.15％,松毛虫赤眼蜂处于优势,拟澳洲赤眼蜂只在一定时期和局部地区占优势。同年对繁蜂站所用的种蜂作考查,拟澳洲赤眼蜂和松毛虫赤眼蜂分别占样本数的85.71％和14.29％,即拟澳洲赤眼蜂占优势,但经在柞蚕卵上转主接蜂传代后,松毛虫赤眼蜂的优势得以提高和稳定,在子蜂中占96.15％。在放蜂区林间复查,松毛虫赤眼蜂仍保持优势,占样本数的99.42％。

SPECIES COMPOSITION OF TRICHOGRAMMA WASPS PARASITIZING DENDROLIMUS PUNCTATUS [LEP.: LASIOCAMPIDAE] IN THE PINE FOREST OF ZHEJIANG PROVINCE AND INFLUENCE OF MASS PROPAGATION WITH OAK SILKWORM EGGS ON SPECIES DOMINANCE OF TRICHOGRAMMA

Investigations were conducted during 1988-1989 in 11 counties of Zhejiang Province on the species composition of Trichogramma parasitizing Dendrolimus punctatus. Species were identified through dissection of male genitalia of the collected wasps. Two species were found, T. dendrolimi and T. confusum, which accounted for 86.85% and 13.15%, respectively, of the total Trichogramma populations in field samples throughout 1988. T. dendrolimi was in obvious predominance over T. confusum, while the latter was dominant in some areas and particular seasons. Contrary to the field situation, samples taken from the stock colonies and mass produced Trichogramma in the Trichogramma production stations revealed that T. confusum was the predominant species. T. confusum and T. dendrolimi accounted for 85.71% and 14.29%, respectively. This situation was reversed through propagating T. dendrolimi on eggs of Antheraea pemyi for several generations prior to the mass production. A stablized rate of 96.15% of T. dendrolimi among offsprings in the mass production was obtained in the production station. In the following field releasing programs, 99.42% of the sampled wasps were found to be T. dendrolimi.