前裂长管茧蜂寄生行为对桔小实蝇幼虫生理指标的影响

Effects of parasitism by Diachasmimorpha longicaudata(Ashmead) on physiological index of Bactrocera dorsalis(Hendel)

通过观察测定了桔小实蝇幼虫生长发育过程中血淋巴蛋白种类和血细胞的变化以及前裂长管茧蜂的寄生行为对桔小实蝇幼虫各项生理指标的影响。结果表明:不同日龄桔小实蝇幼虫的血细胞浓度随着虫龄的增加呈显著上升趋势,由2龄的16.53×106cells/mL,到3龄的30.14×106cells/mL直至蛹前期的35.94×106cells/mL,但血淋巴蛋白种类没有明显变化。和未寄生幼虫相比,寄生后的幼虫各类型血细胞的浓度均下降,但差异均不显著;血淋巴蛋白种类无明显增减,但浓度有所变化;寄生4 h后血淋巴蛋白质浓度显著降低,接近22 h时升高,至化蛹前期浓度再次下降;寄生行为使幼虫的发育历期从8 d延长至9～11d;4日龄幼虫在被寄生后的第4 d起体重显著高于未被寄生的桔小实蝇幼虫。

Normal physiological characteristics of Bactrocera dorsalis （Hendel） and the effects on B. dorsalis after parasitism by Diachasmimorpha longicaudata （Ashmead） were examined in this paper. Re- suits indicated that types of protein in haemolymph had no apparent changes but the concentration of the hemocytes increased obviously from 16. 53×106 cells/mL at the 2na instar, 30. 14×106 cells/mL at the 3rd instar, up to 35.94×106 cells/mL at the prepupal instar. After parasitism, the concentration of two types of hemocytes decreased and the types of haemolymph protein had no apparent changes. At the 4th hour after parasitism, the protein concentration in haemolymph decreased obviously, and began to in- crease at the 22th hour, and then fell down again at the prepupal period. The developmental duration of D. longicaudata prolonged from 8 d to 9 - 11 d. At the first 3 days, there was no difference between the normal and parasitized hosts, but since the 4th day, the weight of parasitized B. dorsalis was more than the normal .