Host selection behavior and incidence of the bark beetle Scolytus kashmirensis (Coleoptera: Curculionidae: Scolytinae)attacking elm (Ulmus spp.) trees in Kashmir

摘要

The status of the incidence of the bark beetle Scolytus kashmirensis Schedl on elm (Ulmus spp.) trees was determined in four districts of the Kashmir Valley in 2009.The incidence of the borer was higher in the Anantnag (25.93%) and Shopian (22.35%) districts of the Kashmir Valley,followed by the Ganderbal (17.14%) and Baramulla (16.67%) districts.The overall infestation recorded in these districts was 20.52%.The beetle under study chewed the scars on twigs of both the host and tentative non-host plants supplied to them in cages but bored and laid eggs in only one of them (the host plant).Both species of elm,Ulmus wallichiana and U.villosa,were susceptible to borer attacks;however,U.villosa showed low susceptibility and high resistance compared to U.wallichiana.Older,taller elms were preferred for feeding by bark beetles and are therefore much more susceptible to its infestation compared to younger elms.This bark beetle species also preferred to oviposit in branches of the host plants with diameters of 9-12 mm.