友恩蚜小蜂生物学特性研究

Studyies on Biological Characteristics of Encarsia amicula Viggiani et Ren

文章对松突圆蚧（Hemiberlesia pitysophila Takagi）天敌友恩蚜小蜂（Encarsia amicula Viggiani et Ren）的生物学特性进行了观察。试验表明，短时间的低温（5℃）对小蜂的活动影响不大，小蜂能恢复正常活动，时间越长，影响越大。低温持续24h，小蜂就会死亡。该小蜂一天中在上午11：00～下午13：00及下午15：00～17：00有两个出蜂高峰。松突圆蚧蚧壳大小与虫体大小的关系并不紧密，有的蚧虫蚧壳大，虫体并不大。蚧壳大小与友恩蚜小蜂羽化孔大小也没有相关性。观察还发现，友恩蚜小蜂可在自己、同种或异种小蜂产过卵的松突圆蚧上产卵，嗜好孕卵期的雌蚧上产卵。小蜂不寄生雄蚧，寄生范围是二龄以上雌蚧。友恩蚜小蜂的产卵量随体长增长而增加，变化曲线呈生长曲线型。在喂食蜂蜜的条件下，羽化第一天产卵占整个产卵量的68％，平均产卵率为65．79％。友恩蚜小蜂自然性比约为40：1，未经交配的友恩蚜小蜂可以繁殖，其子代均为雌性。小蜂在下午4：50左右寄生活动最为频繁。

Biological characteristics of Encarsia amicula Viggiani et Ren which as natural enemy of Hemiberlesia pitysophila Takagi was observed. The test showed that short-term low temperature （5℃） had little effect on activities of the wasp, whereas the low temperature lasted 24 h, the wasp would dead. E. amicula has two fastigiums of emergence in one day： 11：00 am to 13：00 pm and 15：00 pm to 17：00 pm. The testa size of H. pitysophila had little relation not only with the body but also with the hole of the eclosion of the wasp. E. amicula could lay eggs on H. pitysophila which was laid eggs by himself, homogeneity and heterogeneity wasps, and they preferred to laying eggs in the female scale that had been pregnant. E. amicula mainly parasitized female scale that were above 2 stages and didnt parasitize male scale. The fecundity of the wasps were positively correlated with the size of body, and the changed curve was growth curve. Under the condition of feeding honey, the fecundity in the first day of eclosion occupies 68% of the total fecundity of one female adult, the average oviposition rate was 65.79%. The ratio of natural sex of E. amicula was about 40： 1. The wasps without mating could also produce offspring, and the filial generation was all female. The activities of parasitization of E. amicula most occured at about 16：50.