Incidence of Oak Borers and Oak Mortality in Garhwal Himalaya, India

Abstract

The complex interaction of environmental stress, poor natural regeneration and insect pests have lead to oak forest decline in himalayan sub-region. Amongst the insects, stem and wood boring beetles are capable of causing significant oak mortality. The paper reports the outcome of surveys on wood boring beetles carried out in moist temperate oak forests mainly with Ban oak, Quercus leucotrichophora Camus, Moru oak,Q. dilatata Lindl and Q. semicarpifolia Smith in six sites in the Garhwal region of Uttarakand, India. Amongst the two primary Cerambycid wood borers, Aphrodisium hardwickianum White was prominent on Q. Leucotrichophora in disturbed forest tracts in Dehradun (Benog Sanctuary)and Uttarakashi district (Govind Wildlife Sanctuary), (Kannatal) Tehri Garhwal district with infestation in stands ranging from 1 to 34.4 per cent. Another longicorn beetle, Rosalia laterifolia Hope preferred Q.dilatata mainly in Deoban Reserve Forest Chakarata Forest Division in Dehradun district causing 28 per cent tree mortality. 12 species of secondary wood boring beetles were also collected from these 6 sites along with two species of insect natural enemies and four species of Woodpeckers. Management options both silvicultural and chemical control, are given.