Damage potential of the weevil Dicranognathus nebulosus Redtenbacher (Coleoptera: Attelabidae) in the Kumaun region.
Dicranognathus nebulosus is a major pest of Quercus leucotrichophora in the Kumaun Himalayas of Uttar Pradesh. Acorn infestation by the insect was studied in the laboratory and in the field (at 6 oak forest sites) over 2 yr. In the field, acorns were collected from randomly selected trees at 4, 8 and 12 m height, and from the ground. Nearly 54 00 acorns were sampled from trees and 56 000 from the ground. The average percentage infestation was 51.6% in the first year and 50.3% in the second year, and there was no difference in infestation between disturbed and undisturbed areas of forest. Acorns collected from the ground were more infested. Acorns of Q. floribunda were not infested. Only a very small percentage (about 5%) of the weevils survive the whole life cycle.