Population dynamics of walnut aphid, Chromaphis juglandicola Kaltenbach, 1843 (Hemiptera: Aphididae) on Juglans regia (Walnut) in Kashmir

Abstract

Regarded as one of the economically important crops of Kashmir, walnut trees are vulnerable to insect pests and diseases leading to great economic losses every year, thus to have knowledge about various factors that leads to it, is indispensable. The objective of the present study was to evaluate the population dynamics in terms of abundance and distribution of Chromaphis juglandicola in response to biotic and abiotic factors. Sites were monitored for two years from January 2017 to December 2018, in which five trees were randomly selected from two sites and each site was visited fortnightly. The counted collected specimens were identified and sampling protocol was established by seasonal richness peaks. The data depicted that C. juglandicola showed definite seasonal trend with highest population in summer and lowest in autumn with peak population in the month of June. Further, it was observed aphidophagous coccinellids also played a significant role in controlling aphid population. Six beetles were reported during two years of study out of which Calvia punctata and Harmonia diamadata were most abundant.