Life History and Biology of the Elm Bark Beetle Scolytus kashmirensis Schedl (Coleoptera: Curculionidae: Scolytinae) Infesting Ulmus villosa in Kashmir

摘要

Elm bark beetle Scolytus kashmirensis is a key pest of elm nurseries in the social forestry ecosystem of Kashmir. The biological and morphological characters of this species were determined both in field and in the laboratory. The larvae remained inactive throughout the winter which resumed their activity from the third week of March. Pupation started from the first week of April and the first swarming adults appeared from the last week of April. After emergence, the adults fly to suitable trees and undergo maturation feeding for 8.4 (±0.68 SD) days and females laid 46 (±9.45 SD) eggs on an average. The eggs hatched after an incubation period of 11 - 13 days. The five larval instars were distinguished from each other on the basis of the width of head capsule measurements. The larvae completed their development in 40 - 46 days. The pupal stage lasted for 10 - 20 days and finally adults emerge that lived for 45 - 60 days. The single longitudinal maternal gallery measured 42.67 (±11.07 SD) mm (on average) long and the larval gallery was 43 (±10.96 SD) mm (on average) in length. The seasonal distribution of various life stages and the number of generations were also recorded.