Seasonal Incidence and Biodiversity of Flea Beetles (Coleoptera, Alticinae) in a Brassicaceous Vegetable Agro-Ecosystem of Kashmir Valley

Abstract

The qualitative and quantitative survey of flea beetles in the cruciferous vegetable ecosystem in different agro-ecological zones viz., North, South, and Central, of Kashmir valley revealed a total of four flea beetle species, which include Psylliodes tenebrosus Jacoby, Phyllotreta striolata (Fabricius), another different Psylliodes sp. Indet. 1 and Altica himensis Shukla. Phyllotreta striolata was the most predominant species, accounting for 57.88 per cent on kale and 78.68 per cent on turnip during the entire growing season. The values of diversity indices varied evenly amongst the selected sites in both the crops. On kale, the beetles of the overwintering generation emerged from the second fortnight of March up to the end of May depending upon weather conditions. The emergence of the beetles of new generations started in the beginning of June and the highest trap catches were recorded during the second fortnight of July i.e. from 27th to 29th standard weeks. The mean number of trap catches decreased afterwards and minimum trap catch was observed by the end of October. However, in turnip, the population density of flea beetles increased from 32nd to 38th standard weeks and thereafter showed a decline. The study further revealed that the temperature influenced the activity of the flea beetles significantly. All the flea beetle species collected in the current study are presently considered important pests of cruciferous crops.