Impact of dry weather on infestation rate of aphids (Homoptera: Aphididae: Adelgidae) on highland conifers in Azad Jammu and Kashmir
2012
Khan, M.R. (University of Azad Jammu and Kashmir, Rawalakot (Pakistan). Dept. of Entomology) | Idris Bin Ghani. (University Kebangsaan (Malasia) School of Environmental Sciences) | Khan, M.R. (University of Azad Jammu and Kashmir, Rawalakot (Pakistan). Dept. of Entomology) | Hayat, A. | Khan, A.G.
An unusual high infestation of Aphids and Adelgids has been a big challenge for the last 5-10 years in Himalayan highland conifers. The highest attack rate has been observed during the early winter from mid of November and continues until the end of January. The principle aim of the study conducted was to identify the aphid pest species and to find out the factors that contribute in the severe infestation of aphids/adelgids during dry winter and the species variation from six natural forests sites. The interaction between aphids and their host trees were thoroughly studied and there was no apparent indication of genetic variation among the conifer trees. Uniform attack rate was seen on the trees those were under severe water stress. The pine trees from same study site were not attacked at all or less attacked was due to the severity of physiological drought. Soil moisture around the affected and non-affected trees was estimated and there was a significant difference between the availability of gravimetric soil moisture between the attacked (0-25%) and non-attacked trees (50-75%). The most of the startling affect of the damage occurred on terminal portions of upper stems of those trees severely affected by the water stress and true firs that brought by the family Adelegidae. None of the natural enemy of pest was found on a single study site during the peak infestation period of early winter.
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