Pest spectrum and population dynamics of major pests occurring on snake gourd (Trichosanthes cucumerina var. anguina)

Abstract

A field investigation was carried out to study different insect pests occurring on snake gourd (Trichosanthes cucumerina var. anguina) during kharif 2018-19 at the University of Agricultural Sciences, GKVK, Bengaluru. The study revealed the occurrence of 17 species of insect pests belonging to four economically important orders such as Lepidoptera (three species), Coleoptera (five species), Diptera (two species) and Hemiptera (seven species) which are of both major and minor importance. The major defoliator insects such as semilooper, Anadevidia peponis (Fab.) population showed significant positive correlation with morning relative humidity (RH) (r=0.69*), while, leaf miner, Liriomyza trifolii (Burgess) and population of pumpkin caterpillar, Diaphania indica (Saunders) and plume moth, Sphenarches caffer (Zeller) were significantly positively correlated with afternoon RH (r=0.60* and 0.59*, respectively), pumpkin beetle, Aulacophora spp. population showed significant positive correlation with total rainfall (r=0.69*), leaf hopper species had significant negative correlation with total rainfall (r=-0.60*), whereas, mirid bug, Nesidiocoris tenuis (Reuter) population exhibited significant negative correlation with sunshine hours (r=-0.65*).