Polygyny of Tuta absoluta may affect sex pheromone-based control techniques.
The South American tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), has recently invaded Yili region in Xinjiang, China. In this region, sex pheromone-based control techniques are considered promising components of integrated pest management programs. However, the potential parthenogenesis and polygyny of T. absoluta may strongly influence the effectiveness of these techniques. In the first part of this study, the parthenogenetic reproduction potential of females collected from Yili was assessed. Consistent with French and Tunisian populations, these females were also able to reproduce parthenogenetically. However, the Yili population had a much lower capacity to produce viable offspring in F1. Next, the effects of a biased T. absoluta sex ratio on offspring density and tomato plant damage and growth were evaluated. With the exception of the combination 4F+0M (F: female adult; M: male adult), tomato plants infested by 4F+1M, 4F+2M, 4F+3M, and 4F+4M yielded similar quantities of offspring (larvae + pupae) in F1, which indiscriminately affected plant damage and growth. Overall, compared with parthenogenetic reproduction, polygyny in the Yili population of T. absoluta is likely to undermine the effectiveness of sex pheromone-based control techniques in this region. Therefore, growers should be cautious about relying on sex pheromone-based management techniques.