Linking soil physico-chemical properties with the recent upsurge of Lepidiota mansueta (Coleoptera: Scarabaeidae) in sugarcane ecosystem of Majuli river island, Assam, India

Abundance of larval population of Lepidiota mansueta and corresponding plant damage was assessed in ten sugarcane fields at Majuli river island of Assam, India. The mean larval density were 1.4 ± 0.2 and 1.8 ± 0.2 numbers per square meter area inflicted 19.25 ± 3.76 and 20.27 ± 1.38 per cent plant damage. Regression analysis between larval density and plant damage exhibited significant positive relationship during the sampling period 2015 (r = 0.883) and 2016 (r = 0.867). Further, soil physical parameters viz., bulk density (r =-0.804) and sand content (r =-0.482) had significant negative correlations, while compared with soil chemical parameters, soil organic matter (r = 0.834), available nitrogen (r = 0.802) and soil microbial biomass carbon (r = 0.781) showed significant positive correlations, whereas available P₂O₅ (r =-0.466) had significant negative correlation with the larval population.