Fitness of fall armyworm, Spodoptera frugiperda to three solanaceous vegetables

Abstract

The fall armyworm (FAW), Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) is an important agricultural pest that invaded China in the middle of December 2018. As a polyphagous pest, FAW is identified as a serious threat to agricultural production and food security in China. Pepper (Capsicum annuum L.), tomato (Solanum lycopersicum Mill.) and eggplant (Solanum melongena L.) are three of dominant solanaceous vegetables of this country. To our knowledge, the effects of these plants on the performances of FAW have not been well studied. In this study we assessed the fitness of this pest to these three plants. Results showed that FAW can complete its life cycle when fed with tomato and pepper, but not on eggplant. The population parameters of FAW fed with maize (Zea mays L.) and the three solanaceous vegetables were compared using the age-stage, two-sex life table method. Developmental duration was significantly different in the larval stage, but not in the pupae stage. FAW fed with pepper had the longest pre-adult period (41.73 d) and the lightest pupal weight (0.1134 g); the survival rate was lower than FAW fed with tomato. Significant differences were observed in the mean fecundity of female, with the highest (943.95 eggs) laid by FAW fed with tomato. FAW had the shortest mean generation time (T), the highest intrinsic rate of increase (r) and finite rate of increase (λ) on maize, and the highest net reproductive rate (R0) on tomato. Overall, FAW fitness on the three solanaceous vegetables was: tomato>pepper>eggplant. This study provides the foundation for further assessment of FAW risk to solanaceous vegetables and for establishing corresponding control strategies in China.