广赤眼蜂滞育及贮存技术研究

A STUDY ON THE DIAPAUSE AND COLD-STORAGE TECHNIQUE OF TRICHOGRAMMA EVENESCENS

贮存蜂种是赤眼蜂大量繁殖应用中不可缺少的环节,但常温下繁育的蜂不耐冷藏,一般经2～3个月以后,蜂不能羽化或羽化的蜂生活力弱,以致限制放蜂面积和影响防治效果。通过改进繁育技术,人为诱导赤眼蜂滞育,可提高蜂的生活力,使其耐冷藏,便于积累大量蜂种供大面积释放,蜂种得到复壮,保证田间散放优质蜂,提高防治效果。对赤眼蜂滞育的研究,原苏联居领先位置,我国近年亦有涉及这方面的一些报道。

This paper deals with the diapause and cold-storage technique of Trichogramma evenescens.The tests showed that constant temperature 15℃(L:D 24:0 and 0:24), fluctuating temperature 23-11℃(or 15℃)could induce T.evenescens into diapause. The rate of the diapausing prepupa was 85.07%,85.01%,92.16% and 71.67% res- pectively.The influence of long or short photoperiod on the prepupal diapause under low temperature was unsignificant.The last-instar larval stage of T.even- escens was most sensitive to low temperature,and the prepupa was the diapausing stage.So,we must treat it with lower temperature at the earlier developmental stage before prepupation in order to induce it into diapause.The diapaused T. evenescens could emerge normally after long-term cold-storage(more than 2 months). The rate of the emergence was 90.45% when it was stored for 4 months.It is worth to notice that about half of the diapaused parasites could still emerge after cold- storage for 10 months.Their reproductive capacity and sex rate were normal.