The first data on the biology of Ips stebbingi Strohmeyer, 1908 (coleoptera: curculionidae: Scolytinae), a pest of himalayan blue pine

ABSTRACT This paper deals with the studies on the biology and development of the bark beetle Ips stebbingi Strohmeyer, 1908 (Coleoptera: Curculionidae: Scolytinae), a pest of Himalayan blue pine Pinus wallichiana A.B.Jacks. in Kashmir Himalaya. This pest is an aggressive and notorious one, but little is known of its biology. This beetle pest overwinters in adult stage under the bark of host trees P. wallichiana. After emergence, the adults fly to suitable trees and undergo maturation feeding for 4–6 days. Reproduction is polygamous type; two to six females join a male in his nuptial chamber. After mating, each of the females makes one gallery with an average length of 10.76 (±3.30 standard deviation [SD]) cm. The female lays 23.16 (±7.03 SD) eggs on an average. The eggs hatch in 8–18 days. The larvae have five instars and complete their development in 30–45 days constructing larval galleries of 3.83 (±0.63 SD) cm in length. The larvae pupate for 18–28 days and finally the adults emerge to attack new suitable trees. The adults live for 45–70 days, and the total lifespan of this species ranges from 101 to 156 days. The seasonal distribution of various life stages and the number of generations were also recorded.