Seasonal Incidence and Spatial Distribution of Piezodorus lituratus (Hemiptera: Pentatomidae) on Leguminous Crops

Abstract

Seasonal incidence and spatial distribution of Piezodorus lituratus (Hemiptera: Pentatomidae) were investigated on leguminous crops to understand its population dynamics and infestation patterns under field conditions. Systematic surveys were conducted across major pulse-growing areas, and insect abundance was recorded at different crop growth stages along with environmental parameters. Results indicated distinct seasonal fluctuations in population density, with peak incidence occurring during flowering and pod formation stages when host plant nutritional quality is highest. Early vegetative stages showed comparatively low infestation levels, while progressive population build-up was observed with crop maturity. Spatial distribution analysis revealed an aggregated pattern of occurrence within fields, with higher insect concentration along field margins and patchy hotspots in areas with dense canopy and reduced disturbance. Environmental factors such as temperature and relative humidity showed a significant positive correlation with pest abundance, whereas heavy rainfall events temporarily reduced population density. Host plant phenology played a critical role in determining infestation intensity, with reproductive stages being highly susceptible to bug feeding damage. The study also recorded the presence of natural enemies, including predatory insects and parasitoids, which contributed to partial regulation of pest populations under field conditions. However, their impact was insufficient to prevent economic damage during peak infestation periods. These findings highlight the importance of timely monitoring and targeted management strategies for effective control of P. lituratus in leguminous cropping systems. The results provide a baseline for developing integrated pest management approaches incorporating habitat manipulation, biological control, and timely insecticide applications to minimize yield losses in pulse crops.