中国本土寄生蜂广大腿小蜂对外来害虫美国白蛾的生物防治潜力OA

[Aim]This study aims to clarify the biocontrol potential of the native pupal parasitoid Brachymeria lasus in China against the fall webworm,Hyphantria cunea,a major invasive pest.[Methods]Under laboratory conditions,the parasitic functional responses of B.lasus to H.cunea pupae were determined at different temperatures(20,25 and 30 ℃),and the intraspecific interference effect was evaluated at varying parasitoid densities(1-5 individuals/can)within a fixed space of 474 cm3.[Results]At 20,25 and 30℃,the parasitic functional responses of B.lasus to H.cunea pupae all fitted the Holling type Ⅱ model,with the daily number of parasitized hosts per female increasing significantly as the host density increased.B.lasus exhibited the strongest parasitic capacity at 25 ℃.The daily number of parasitized hosts per female reached 16.90 individuals when the host density was 30 individuals/can.Analysis of model parameters indicated that the theoretical daily number of parasitized hosts per female and parasitic efficiency(a'/Th,the ratio of instantaneous attack rate to handling time)at 25 ℃ were the highest(45.2489 individuals and 42.2127,respectively),followed by those(24.0385 individuals and 25.2404,respectively)at 30 ℃,and those at 20 ℃ were the lowest(17.9856 individuals and 24.4856,respectively).Searching efficiency analysis showed that the searching efficiency of B.lasus decreased with increasing host density at all temperatures,exhibiting typical inverse density dependence.In the interference effect experiment,as the parasitoid density increased from 1 to 5 individuals/can,the total number of parasitized hosts significantly increased from 15.40 to 58.90 individuals.However,no significant differences were observed in the number of parasitized hosts per parasitoid or per capita parasitism rate,indicating no obvious intraspecific interference within the tested parasitoid density range.[Conclusion]Among the tested three temperatures,25 ℃ is the optimal temperature for maximizing the parasitic efficiency of B.lasus.Furthermore,B.lasus exhibits weak interference effects in confined spaces.Therefore,it is recommended to set 25 ℃ as the optimal temperature parameter for mass rearing of B.lasus indoors.Given its negligible interference effect in small-scale environments indoors,an"inundative release"strategy is supported for forest biological control applications,where increasing release density can fundamentally enhance the suppression of high-density H.cunea populations.