Original paper
Reproductive and biological control performance of in vitro and in vivo reared Trichogramma dendrolimi on Spodoptera frugiperda
Lü, Xin; Qiu, Ran-Ran; Han, Shi-Chou; Desneux, Nicolas; Zang, Lian-Sheng; Li, Jun
Entomologia Generalis Volume 45 Number 1 (2025), p. 175 - 183
published: Feb 26, 2025
published online: Feb 6, 2025
manuscript accepted: Jan 8, 2025
final revised version received: Dec 5, 2024
manuscript revision requested: Sep 9, 2024
manuscript received: Jul 23, 2024
DOI: 10.1127/entomologia/2025/2874
Open Access (paper may be downloaded free of charge)
Abstract
Trichogramma (Hymenoptera: Trichogrammatidae) is a potential egg parasitoid against the invasive pest, Spodoptera frugiperda (Lepidoptera: Noctuidae). However, the control capacity of in vitro reared Trichogramma is not known. In this study, the reproductive and control effectiveness of in vitro and in vivo reared Trichogramma dendrolimi on S. frugiperda were investigated under lab and semi field conditions. Results showed that individual T. dendrolimi females of both groups caused more than 75% of S. frugiperda eggs not to hatch into larvae in indoor experiments. S. frugiperda eggs were not suitable for reproducing T. dendrolimi continuously because the wasps caused a higher rate of mortality to host eggs, which resulted in a high proportion of wizened host eggs and lower number of wasp offspring for reproduction. The optimal parasitoid to host ratio for the in vitro reared group was 1:3 and 3:1 for indoor reproduction and outdoor releases respectively, while it was 1:1 and 2:1 for the in vivo reared group. The hatching rate of double-layer S. frugiperda egg masses parasitized by in vitro reared group was 18.54% and 21.48%, under a parasitoid to host ratio of 3:1 and 1:2 respectively, in indoor experiments, while that parasitized by in vivo reared group was less than 2%. The results suggested that in vitro and in vivo reared T. dendrolimi are viable biological control agents for S. frugiperda. Different strategies, which ensure an effective control and population establishment in the field but also save costs should be considered.
Keywords
fall armyworm • egg parasitoid • biocontrol • host ratio • mass rearing • field release