黄玛草蛉捕食米蛾卵的功能反应与数值反应

Functional and numerical responses of Mallada besalis feeding on Corcyra cephalonica eggs

针对天敌控害潜能评价和天敌昆虫大量饲养的基础理论问题,以一种重要的捕食性天敌黄玛草蛉Mallada besalis Walker捕食米蛾卵的功能反应和数值反应研究为例,开展研究。结果表明,黄玛草蛉幼虫对米蛾卵的捕食功能反应符合HollingⅡ型方程,其捕食量在一定范围内随着猎物密度的增加而增加,最后趋近一个稳定值,且与是否供水有关,供水时3龄幼虫的理论捕食能力最大,为3205.1粒卵/d。数值反应研究结果表明,不同密度的米蛾卵对黄玛草蛉的生长、发育、繁殖有着显著的影响。随着猎物密度增大,黄玛草蛉幼虫的发育速率、雌虫的产卵量、孵化率及雌性比增大,成虫的寿命延长,最后趋于稳定。米蛾卵密度5、10、20、30、50卵/d。分别是黄玛草蛉幼虫存活、幼虫化蛹、成虫羽化、后代卵孵化及世代延续的临界值。并讨论了功能反应和数值反应研究在天敌利用研究中的侧重点和重要性。

The functional and numerical responses of an important predator Mallada besalis Walker feeding on Corcyra cephalonica eggs were respectively carried out in laboratory. The results showed that the functional response conformed to Holling Type II equation. In a certain range, the predation of M. besalis larvae increased with an increase of the prey＇s density then tended to be a steady value, it was also related to whether there was water supply.When water was supported, the theoretical predation of the 3rd instar larvae was largest, it was 3205.1 C. cephalonica eggs per day. The results of numerical response research showed that the growth, development and reproduction of M. besalis larvae were significantly influenced by C. cephalonica egg＇s density. The developmental rate, female fecundity, hatching rate, female ratio of M. besalis larvae, and adult longevity increased with an increase of C. cephalonica egg＇ density, then tended to be steady. The C. cephalonica egg＇s density threshold for larvae survival, larvae pupation, adult emergence, offsping eggs hatching and population maintenance were respectively 5, 10, 20, 30 and 50 eggs per day. In the research of natural enemy large-scale breeding and control potential against pest, numerical response emphasized on the dependence of predators on prey density and the prey density thresholds would cause predator population to decline. This would provide theoretical basis for fodder allotment, cost control and enhanced the predator＇s capability of controlling pest when alternative host was added in field. It would be concluded from the above results that M. besalis has potential value to he considered as a biological control agent. And we discussed the importance and emphasis of functional and numerical responses in the natural utilization.