取食不同糖分对卵育型寄生蜂潜蝇姬小蜂雌蜂寿命和卵子发生的影响

取食糖类物质有利于延长具寄主取食特性的卵育型寄生蜂的寿命。为了明确自然界常见糖分对卵育型寄生蜂的营养功能差异， 本研究比较了取食葡萄糖、 果糖、 蔗糖、 海藻糖和松三糖5种常见糖分对斑潜蝇类害虫的优势寄生蜂潜蝇姬小蜂Diglyphus isaea雌蜂寿命和卵子发生的影响。结果显示: 取食5种糖均能显著延长雌蜂寿命（P<0.0001）； 取食果糖的雌蜂寿命显著长于取食葡萄糖、 蔗糖、 海藻糖和松三糖的雌蜂寿命（P<0.0001）， 取食葡萄糖、 蔗糖和海藻糖3个处理间差异不显著（P>0.4234）， 但均显著长于取食松三糖（P<0.0001）； 同时， 各个处理的雌蜂寿命与其个体大小均分别呈显著正相关关系。初羽化雌蜂卵巢中没有Ⅲ级卵子（即成熟卵子）； 清水处理的雌蜂， 24 h后卵巢中Ⅲ级卵子达到高峰， 48 h时则全部重吸收； 而取食5种糖的雌蜂， 卵巢中的Ⅲ级卵子和总卵子数量整体上均呈现先显著上升而后逐步下降的趋势， 取食不同糖分的雌蜂卵子形成高峰期的时间不同， 而且取食不同糖分的雌蜂间Ⅲ级卵子高峰日数量和总卵子高峰日数量均无显著差异（P>0.05）。该研究结果为潜蝇姬小蜂的大量室内饲养和田间释放提供了依据。

Effects of feeding different sugars on longevity and oogenesis in female adults of the synovigenic parasitoid Diglyphus isaea (Hymenoptera:Eulophidae)

Sugar diets can prolong longevity of synovigenic parasitoids. To understand the differences in the nutritional function of naturally occurring sugars to synovigenic parasitoids, the longevity and oogenesis of Diglyphus isaea (Walker) ,a predominant parasitoid of Liriomyza leafminer provided respectively with glucose, fructose, sucrose, trehalose and melezitose, were compared in this experiment. The results showed that the longevity of female wasps feeding on sugars was prolonged significantly (P < 0. 0001) . Longevity of wasps feeding on fructose was significantly longer than that feeding on glucose,sucrose,trehalose and melezitose,respectively (P < 0. 0001) . However,no differences were observed in the longevity of wasps feeding on glucose,sucrose and trehalose (P > 0. 4234) ,which was,however,significantly longer than that feeding on melezitose (P < 0. 0001) . The longevity was positively related with body size when female wasps fed on different sugars. Newly emerged females did not bear the third grade eggs (mature eggs) in their ovaries. When water was available,the number of the third grade eggs reached the maximum at 24 h after eclosion,while all of the third grade eggs were reabsorbed at 48 h. When the parasitoids fed on the five kinds of sugars,the number of the third grade eggs and the total number of eggs including immature and mature eggs significantly increased and then declined gradually. Meanwhile,the peak time of the total number of eggs varied among the different treatments,but the maximums of both the third grade eggs and total eggs had no significant differences among female wasps feeding on different sugars (P > 0. 05) . The results provide a basis for mass-rearing indoors and mass-releasing in fields of the parasitoid D. isaea.