Effects of Instar,Food and Density on Larval Cannibalism of Agrotis ipsilon(Lepidoptera:Noctuidae)

Wei Dongshun; Guan Hanjie; Zou Xiao; Yang Maofa; Yang Xiang; Yu Xiaofei

doi:10.14083/j.issn.1001-4942.2024.05.016

Abstract：Agrotis ipsilon is an important underground pest at the seedling stage of agricultural and forest-ry crops.Cannibalism affects population growth and decline of Agrotis ipsilon,which is of great significance for clarifying its population dynamics and predicting prevention and control.In this study,the A.ipsilon popula-tions fed with corn,cabbage,tobacco and artificial feed were established in the laboratory,and the effects of instar,food and density on larval cannibalism were determined,aiming to clarify the cannibalism characteris-tics of A.ipsilon.The results showed that instar,food and density had significant effects on the corrected can-nibalism rate of A.ipsilon larvae.Among them,the highest corrected cannibalism rate in the four populations during the same instar period was found in the 5th instar,and the lowest was found in the 2nd instar.The de-gree of cannibalism of the four populations ranged as artificial feed population>cabbage population>corn population>tobacco population.The highest corrected cannibalism rate occurred at 30 heads per bottle of feeding density.After mixing different instars,the 2nd instar larvae had the highest probability of being killed by older larvae in each population,while the 5th instar larvae had the lowest probability.After the 5th instar larvae of different populations were mixed,the probability of being killed was the highest in corn population,and lower in artificial feed population.Instar,food and density all had significant effects on the variation of corrected cannibalism rate of larvae,among which,instar had the greatest influence(26.80%)and food had the least influence(4.40%).Instar had a significant effect on the variation of probability of being killed,ex-plaining 11%of the variation.