Life Cycle and Feeding Behaviour of Rice Stem Borer Species in Southeast Asian Regions' Paddy Fields

Abstract

Rice stem borers are among the most damaging pests in paddy fields and are a growing concern for farmers. This is concerning due to the decline in rice production they may cause, especially in areas with high infestation, where infestation coincides with critical stages of paddy growth. This review discusses existing knowledge on the life cycle, feeding behaviour, and oviposition patterns of six main recognised species in Southeast Asian regions, particularly Scirpophaga incertulas, Scirpophaga innotata, Chilo suppressalis, Chilo polychrysus, Chilo auricilius, and Sesamia inferens. Their distinct characteristics in egg-laying behaviour, feeding sites, and the infestation timing were then further discussed and correlated with rice phenology to observe the variation of damage expression and how it affects yield, ultimately. Though common symptoms such as deadheart and whitehead are expected after infestation, the occurrence and severity of damage, as well as the chances of plant recovery, may differ. The differences between the infestation events are crucial, especially when considering management controls in the field to produce better alignment with paddy growth stages, together with suitable ecological factors. However, there is still limited information on specific economic thresholds in many parts of Southeast Asia. This research gap provides the need for future research, as it may support more targeted IPM control strategies and reduce dependence of farmers on broad-spectrum insecticides.