Evaluation of the Predatory Potential of Arma chinensis to the Larvae of Pieris rapae

WU Qiong-mei

doi:10.13651/j.cnki.fjnykj.2025.07.006

Abstract：In order to clarify the characteristics of predatory behavior of Arma chinensis on the larvae of Pieris rapae and evaluate the predatory capacity and control potential of A.chinensis,the predatory behavior and the predatory capacity of adults and nymphs of A.chinensis to the larvae of P.rapae were studied by means of indoor observation method combined with the method of HollingⅡdisc equation fitting.The results showed that the predatory behavior of A.chinensis on the larvae of P.rapae could be divided into 4 kind of behaviors:searching,piercing-sucking,waiting and feeding.A.chinensis first fed on the larvae of P.rapae by piercing-sucking through its chest,or by piercing through multiple positions on its body.After the larvae of P.rapae were controlled,multiple A.chinensis would gather to feed.The predatory functional response of 4th and 5th instar nymphs,male and female adults of A.chinensis to 4th instar larvae of P.rapae was in accordance with the Holling Ⅱdisc equation model.The predation amount of A.chinensis increased with the increase of the density of the larvae of P.rapae,while the searching efficiency decreased with the increase of the density of the larvae of P.rapae.The instantaneous attack rate to the 4th instar larvae of P.rapae was as followed:4th instar nymphs(0.927)>5th instar nymphs(0.906)>female adults(0.894)>male adults(0.877).The maximum daily predation of female adults of A.chinensis was 7.645 individuals.The predation of the 5th instar nymphs and male adults of A.chinensis was equivalent,and their searching efficiency was similar.This study showed that both the adults and 5th instar nymphs of A.chinensis had better predation ability on the larvae of P.rapae.Therefore,during the prevention and control,a large number of A.chinensis could be released in the early stage of P.rapae occurrence,thus to reduce the population of P.rapae and minimize their harm to cruciferous vegetables.