枸杞木虱啮小蜂繁殖生物学研究

枸杞木虱啮小蜂Tamarixa lyciumiYang是枸杞木虱Paratrioza sinica Yang&Li若虫期的重要寄生性天敌。在实验室对其繁殖生物学特性进行了研究,结果如下:枸杞木虱啮小蜂大多进行两性生殖,孤雌生殖后代均为雄性,其自然性比为1.80:1。在15～35℃间,随温度升高,枸杞木虱啮小蜂发育历期缩短;从卵发育到成虫时需要8.22℃以上的有效积温217.21日·度。枸杞木虱啮小蜂在25℃恒温条件下繁殖力最高,35℃最低,寿命随温度的升高而缩短。在不同营养条件下,喂食20%蜂蜜的条件最适宜其繁殖,其次为20%蔗糖溶液,补充清水只可延长其寿命而不能提高繁殖力。5℃冷藏枸杞木虱啮小蜂蛹15d以内,不影响其正常羽化,冷藏20d或20d以上,羽化率显著降低;冷藏30d内对羽化后雌雄蜂寿命无明显影响,且从冷藏蛹中羽化的雌蜂寄生能力未受显著影响。

Reproductive biology of Tamarixa lyciumi

The reproductive characteristics of Tamarixa lyciumi Yang,a parasitioid of nymphs of Paratrioza sinica Yang Li,were studied under laboratory conditions.Sexual reproduction in T.lyciumi occurs much more often than parthenogenesis,which produces only male offspring.The sex ratio is 1.80：1.Environmental conditions had a marked influence on development,longevity and fecundity.Temperature had the greatest effect;increasing temperature shortening the developmental period.The low temperature threshold of development from egg to pupa is estimated to be 8.22℃ respectively,and the effective accumulative temperature from egg to pupa is 217.21 degree days.Adult longevity decreased with temperature from 15℃ to 35℃.Fecundity was highest at 25℃ and lowest at 35℃.Adults provided with 20% honey water were the most fecund;those provided with 20% sucrose water were the next most fecund.Although providing water prolonged adults life span it did not increase their fecundity.There was no significant difference in the number of progeny per female at 5℃ over 15 days.The emergence rate decreased markedly if pupae were kept at 5℃ longer than 15 days,however,the life span of adults from pupae kept at 5℃ for up to 30 days was not significantly different to the control,nor was there any difference in female fecundity between females that emerged from these pupae and the control.