南京地区豆秆黑潜蝇寄生蜂发生情况调查

在南京地区寄生于豆秆黑潜蝇的寄生蜂计有8种,其中寄生率最高的是豆秆蝇瘿蜂与豆秆蝇茧蜂。若将寄当年滞育至翌年羽化的被寄生的蝇蛹计算在内,寄生蜂在后期(9月)对存活蝇的寄生率接近于100％。各种寄生蜂的寄生数量与大豆植株不同部位之间的联系十分显著。豆秆蝇瘿蜂在大豆主茎内最多,叶柄内最少;长腹金小蜂与两色金小蜂则在叶柄内最多,主茎内最少;其他蜂种在植株各部位的数量差异不显著。8种寄生蜂在田间的分布型经卡方检验与Taylor指数法则的测定,在各个时期和大、小样本均属泊松型。

INVESTIGATION ON THE OCCURRENCE OF AGROMYZIDFLY PARASITES IN SOYBEAN FIELDS OF NANJING AREA

There are eight species of parasites on soybean agromyzidfly, belonging to the braconids, chalcid wasps and cynipoids, with three external (ectoparasitoids) and five internal (endoparasitoids) in Nanjing. Those of special value are Cronotoma sp., Bracon sp. and Stinoplus sp.If the diapause fly pupariums being parasitized are involved in estimate, the rate of parasite on soybean fly approximate to 100% in the late period.The proportion of parasites occurring in each species is not the same on different parts of soybean plants. Gronotomasp. was more abundant at the site of stem and least abundant at leaf stalk. Whereas the reverse was true for Stinoplus sp. and Rohatina sp. the proportions of the other four are nearly the same on different parts of soybean plants.Using X~2 test and Tayloy's Power Law we tested the field distribution pattern of the parasites. The results show that agreement with a poisson series is accepted at the 95% probability level. It is therefore possible that the community of eight parasite species are randomly distributed within the soybean plant in different seasons and sizes of samples.