Ovipositional preferences of fall armyworm, Spodoptera frugiperda, on different host plants under laboratory conditions

The interaction between insects and their host plants is essential for understanding successful oviposition, particularly for polyphagous insects. The fall armyworm (FAW), Spodoptera frugiperda, is a significant pest affecting over 300 host plant species. In light of its impact, an experiment was conducted to examine FAW oviposition on Brassica rapa L., B. oleracea var. capitata, and Zea mays L. Results from this study revealed a notable influence of host plant species on FAW oviposition preferences. The highest egg count (675 ± 32.4 eggs) was recorded on maize, specifically on the maize strain of FAW. In choice experiments, the FAW maize strain showed a strong preference for ovipositing on maize. Interestingly, neither the mustard strain (139 ± 37.3 eggs) nor the cabbage strain (37.0 ± 4.6 eggs) laid the highest number of eggs on their respective host plants. Among reproductive parameters, the primary difference observed was in the oviposition period. For adult diets, the highest fecundity, with 1188 ± 64.84 eggs, was achieved with a honey + protein solution diet. These findings suggest that adult diet has a substantial impact on oviposition period and can be beneficial for mass-rearing FAW in laboratory settings. In conclusion, the results indicate that FAW in Pakistan still shows a strong preference for maize and has not adapted to other host plants as primary options. This preference for maize warrants focused pest management strategies to keep FAW populations below threshold levels and minimize crop damage.