Impact of Rice and Potato Host Plants Is Higher on the Reproduction than Growth of Corn Strain Fall Armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae).

Abstract

Simple SummarySince 2016, the fall armyworm (FAW), an invasive pest native to tropical and subtropical regions of the Americas, has invaded Africa and further spread into Asian countries. FAW is a polyphagous species, although the invaded strain mostly damages corn rather than any other host plants. Studies on the biology of corn strain FAW reared on three different host plants: corn, rice, and potato, using the age-stage, two-sex life table, showed that growth, development, survival, and reproduction rate of the corn strain FAW were differentially affected by rice and potato host plants. The reproduction rate was highly affected than other parameters such as growth, development, survival rates. Our results provide important information for the understanding of the population dynamics of FAW and an appropriate management strategy in the newly FAW-invaded agricultural ecosystems.The fall armyworm (FAW), Spodoptera frugiperda, is an invasive pest species that has recently increased its range in most African and Asian countries, causing significant losses to crop yields, especially corn. To develop effective management strategies, it is particularly important to study the biology of FAW in various crops. Here, we utilized the age-stage, two-sex life table to examine the development, survival, and reproduction rate of the corn strain FAW on three different host plants: corn, rice, and potato. The corn strain FAW successfully completed its life cycle in rice and potato, as well as corn plants. However, the growth, developmental time, survival, and reproduction rate differed among the three host plants. The preadult survival rates in corn, rice, and potato were 92%, 81%, and 77%, respectively. Similarly, mean generation time was significantly shorter in corn (35 days), followed by rice (41 days) and potato (42 days), indicating more generations in corn. Interestingly, the net reproduction rate varied greatly among the three host plants. In corn-fed FAW, the net reproduction rate was 472 offspring per individual, whereas, in rice and potato crops, the rates were only 213 and 86 offspring per individual, respectively. Our results suggest that alternative host plants, such as potato and rice, have more effect on reproduction than the growth of corn strain FAW. These results may be useful in predicting the population dynamics of FAW and understanding the potential damage to crops, thus contributing to an appropriate management strategy in the newly FAW-invaded agricultural ecosystems.