Occurrence of common aphidophagous natural enemies on blackgram

Abstract

Investigation on, “management of major insect pest of blackgram under organic farming” was carried out at the Instructional Farm, Rajasthan College of Agriculture, Udaipur during monsoon (July, 2013) and (July, 2014) seasons with the objectives to study the qualitative and quantitative abundance of major insect pests of blackgram and their associated natural enemies. The aphid pest recorded on blackgram was Aphis craccivora (Koch). Among the aphidophagous predatory guild, the major insect groups included, coccinellids, Coccinella septempunctata (L); Cheilomenes sexmaculata (Fab.) and syrphid flies, Ischiodon sp. were recorded feeding aphids on blackgram; the carabid, Chlaenius aspericollis (Bates); spiders; reduviid predatory bugs and wasps were also collected from the crop area. The seasonal mean population of aphids was higher during 1st week of September (36th SMW) during 2013 and 2nd week of September (37th SMW) during 2014 with mean population of 42.33 and 37.33 aphids/5 plants in the respective years. The mean density and relative density values were the maximum (8.0 & 78.27 %) for coccinellids during 2013, followed by that for syrphid fly (2.78 & 21.73 %) and relatively more as compared to 2014.