Feeding and oviposition preferences, and fitness, of Spodoptera frugiperda with respect to four important crops in the Nanfan area
Author of the article:TANG Xue, Lü Bao-Qian, TANG Ji-Hong, LU Hui, LIN Nan-Fang, WANG Xiu-Ting, CHEN Yu-Ying
Author's Workplace：Environment and Plant Protection Institute, Chinese Academy of Tropical Agriculture Sciences, Key Laboratory of Integrated Pest Management on Tropical Crops, Ministry of Agriculture and Rural Affairs, Hainan Key Laboratory for Monitoring and Control of Tropical Agricultural Pests, Haikou 571101, China; Sanya Research Institute, Chinese Academy of Tropical Agriculture Sciences, Hainan Key Laboratory for Biosafety Monitoring and Molecular Breeding in Off-Season Reproduction Regions, Sanya 572025，China
Key Words：host plants; developmental period; fecundity; survival rate
Abstract：
[Objectives] To determine the feeding and oviposition preferences, and fitness, of Spodoptera frugiperda feeding on four important crops (corn, chili, rice and peanuts) in the Nanfan area. [Methods] The leaf disc method was used to determine the relative preference of S. frugiperda larvae for each of the above four host plants. Oviposition preferences were determined by restricting adult females to one of the four host plants and comparing the number of eggs masses, number of eggs, percentage of egg mass and percentage of eggs, laid on each host plant species. The developmental duration and survival rate of larvae and pupae, and adult female longevity and fecundity, were compared between insects raised on different host plants. [Results] Different larval instars showed a strong preference for corn, but preference for the other three host plants tended to increase with larval instar. The four host plants can be ranked in terms of preference as follows: corn > rice > peanut > pepper, and in terms of suitability for oviposition as: corn > peanut > pepper > rice. The number of eggs laid on each of the four host plants was: corn (1 208.60 ± 34.91), peanut (331.40 ± 32.83), pepper (186.60 ± 20.14) and rice (169.20 ± 27.77). Most eggs were laid on the second day on corn and peanuts, and on the third day on chili and rice. In addition, the developmental duration of larvae on the four host plants can be ranked as follows: pepper > rice > peanut > corn. Larvae could not develop to the sixth instar on pepper. The survival rate of larvae and pupae on the four host plants can be ranked: corn > peanut > rice > pepper. Almost all larvae died at the fourth instar stage on pepper. [Conclusion] The four different host plants tested significantly affected the development, fecundity, survival and longevity of S. frugiperda. Host plants can be ranked in terms of adult life span as follows: corn > peanut > rice, and in terms of the number of eggs laid per female as: corn > rice > peanut. S. frugiperda can successfully reproduce on corn, rice and peanut, but cannot complete its life cycle on pepper.