Biology of The Giant Willow Aphid Tuberolachnus salignus (Gmelin) (Homoptera : Aphididae) in Cold Arid Zone of Himachal Pradesh

The alates of giant willow aphid Tuberolachnus salignus (Gmelin), a serious pest of willow (Salix spp) in the dry temperate zone of Himachal Pradesh first appeared on S. viminolis at Tabo (Lahaul and Spiti) in the first week of July. The progeny multiplied parthenogenetically throughout the period of infestation (July-December) by completing overlapping generations. The nymphal period and adult longevity varied from 12.4 to 27.4 and 20.6 to 42.4 days while fecundity was in the range of 15-50 nymphs per female depending on temperature which fluctuated between − 15 to 38 ° C. Alates appeared in the colonies from October to December but no sexuals were observed on Salix/I>.