黑水虻幼虫的耐饥力及饥饿幼虫复食后的生物学特性

【目的】旨在明确黑水虻Hermetia illucens幼虫的耐饥力及饥饿幼虫复食后的发育、生殖力等生物学特性,为评估饥饿对黑水虻后续发育的影响并指导生产实践提供依据。【方法】将不同日龄或不同体重黑水虻幼虫进行不同时长的饥饿处理,测定和分析其耐饥力与日龄、百头重的关系;对7日龄幼虫进行不同时长的饥饿处理后再复喂,测定不同饥饿时长对其预蛹出现时间、总预蛹率、预蛹重、成虫繁殖等的影响。【结果】黑水虻幼虫饥饿后的半数致死时间(LT₅₀)与日龄成指数关系,与体重呈线性相关。7日龄幼虫的耐饥力较强,LT₅₀超过了50 d,饥饿30 d时存活率仍然达到了95%。百头重小于0.5 g的个体,其LT₅₀小于30 d;百头重在2～2.5 g的个体,其LT₅₀在45～70 d。幼虫超过8日龄时或百头重超过4.5 g时,多数个体在饥饿5 d时就提前进入了后续发育阶段。7日龄幼虫饥饿40 d内复食,其预蛹率未受到影响,但预蛹重显著增加;短期饥饿(0～10 d)对其成虫产卵量无显著影响,长期饥饿(30～40 d)使其成虫产卵量显著下降;饥饿长达30 d以上时,卵孵化率也显著降低。【结论】本研究明确了不同体重或不同日龄的黑水虻幼虫都具有一定的耐饥力;饥饿幼虫复食后预蛹重显著增加。

Starvation tolerance and biological characteristics after starvation and refeeding of Hermetia illucens (Diptera: Stratiomyidae) larvae

【Aim】 The aim of this study is to clarify the starvation tolerance of Hermetia illucens larvae and to examine the biological characteristics of development and fertility of starved larvae after refeeding, so as to provide a theoretical basis for assessing the effects of starvation on the subsequent development of H. illucens larvae and a guidance on production practices. 【Methods】 H. illucens larvae of different day-old or with different body weights were subjected to starvation for different periods of time. The relationships of starvation tolerance of the larvae with their day-old and body weight were established. Biological characteristics of 7 day-old larvae after being starved for different time and refeeding, including the time of prepupal appearance, cumulative prepupal rate, prepupal weight, and adult reproduction, were assayed. 【Results】 The median lethal time (LT₅₀) of H. illucens larvae after starvation was exponentially related to their age in days and linearly related to their body weight. The 7-day-old larvae had relatively stronger starvation tolerance, with the LT₅₀ value exceeding 50 d and the survival rate of 95% after 30 d starvation. As for the individuals with the body weight less than 0.5 g per hundred larvae, their LT₅₀ value was less than 30 d. As for the individuals with body weights 2-2.5 g per hundred larvae, their LT₅₀ value was 45-70 d. When the larvae over 8-day-old or heavier than 4.5 g per hundred individuals were subjected to starvation for 5 d, most of them entered the subsequent developmental stage ahead of time. During 0-40 d starvation, the prepupal rate had no obvious change, but the prepupal weight increased significantly. Short-term starvation (0-10 d) of larvae had no significant effect on the egg-laying amount of adults, but long-term starvation (30-40 d) of larvae had a significant effect on the egg-laying amount of adults. Moreover, the egg hatching rate decreased significantly when the larvae were subjected to starvation for more than 30 d. 【Conclusion】 The results suggest that H. illucens larvae of different day-old or with different body weights all show certain starvation tolerance, and the prepupal weight of starved larvae increases significantly after refeeding.