花绒寄甲卵储存时长对其幼虫发育和成虫数量的影响

目的 ]明确花绒寄甲卵储存条件对其幼虫和蛹发育历期及成虫羽化数量的影响。方法 ]观察和记录了经不同储存时长的花绒寄甲卵的孵化率的变化。同时,将初孵幼虫接入寄主,观察寄甲幼期发育和羽化情况。结果 ]表明,在12℃,RH 60%条件下,寄甲卵储存时长对其孵化率、幼虫期、蛹期、结茧率、羽化率以及数量和体质量均有显著影响。当卵储存时长小于45 d时,其孵化率均大于92.6%,之后开始显著下降。储存60d,孵化率下降到62.1%,储存90d后其孵化率为0。其结茧率从储存0d的45.7%上升到15d的54.8%,之后开始下降,储存60 d,结茧率显著下降到仅有26.1%。不同储存时长下,其羽化率介于80.7%~96.2%之间。其幼虫期随卵储存时长的增长而总体延长,而蛹期呈不规律变化。成虫羽化数以卵储存15 d的处理最多,平均为5头·个^-1寄主,之后开始下降,储存30 d,数量下降到4头,储存45 d和0 d的数量一样,平均约为3头,储存60 d,数量下降到约2头,储存75 d,数量下降到不足1头。储存15 d,成虫单头体质最大,平均为0.030 g·头^-1,显著高于其他处理。结论 ]综合以上结果表明,在12℃,RH 60%条件下,花绒寄甲卵的适宜储存时长为45 d内,而储存15 d对花绒寄甲的发育最有利。

Effect of Egg Storage Period on the Larva and Pupa Developmental Duration and Adult Quantity of Dastarcus helophoroides(Fairmaire)

Objective] To understand the effects of egg storage period on the immature development and adult quantity of Dastarcus helophoroides(Fairmaire). Method] Six groups of fresh parasitoid eggs were stored for 0, 15,30, 45, 60, 75, and 90 days in the condition of 12 ℃ and RH 60%. These parasitoid eggs treated were then placed at27 ℃ and RH 60% for hatching. The newly hatched parasitoid larvae were inoculated on a host, and the immature durations, cocooning rate, eclosion rate, numbers of adults, and weight of individual adult were subsequently recorded. Result] The results showed that different low-temperature storage duration for parasitoid eggs would significantly influence their hatching rate. The hatching rates were higher than 92.6% as the eggs stored less than 45 days;while the hatching rates decreased to 62.1% and 44.4% when the eggs were stored for 60 and 75 days, respectively.Similarly, the parasitoid larval and pupal durations, cocooning and eclosion rate, numbers of adults, and weight of individual adult also showed significant differences under different egg storage durations. The cocooning rate increased from 45.7% to 54.8% as the eggs were stored from 0 to 15 days, but decreased to 26.1% once the eggs were stored for 60 days. The relative high eclosion rates were observed which ranged from 80.7% to 96.2% in different treatments. The larval duration was prolonged with the increase of egg storage period, but the pupal duration showed irregular fluctuations. The maximum amount of emerged adults was 5 adults for the treatment of eggs stored for 15 days. In addition, the mean body size of adult incubated from the eggs under 15 days of egg storing treatment was invariably larger than that from that of other treatments. Conclusion] It is proved that the optimum cold storage period of D. helophoroides eggs is 15 days, and the acceptable stored period should not exceed 45 days.