Swaminathan, R.Meena, Anil2017-08-102017-08-102014Meena and Swaminathan, 2014http://krishikosh.egranth.ac.in/handle/1/5810028318Diversity of Aphidophagous Natural Enemy Guild in MaizeThe present investigation on, “Diversity of aphidophagous natural enemy guild in maize” was carried out at the Instructional Farm, Rajasthan College of Agriculture, Udaipur during summer (zaid) (April to July, 2013) and kharif (July to October, 2013) seasons with the objectives to study the diversity of aphids of maize and their natural enemies and evaluate the predation potential of major insect groups of the aphidophagous guild in the field and laboratory. The major aphid recorded on maize was Rhopalosiphum maidis (Fitch) and on cowpea (as an intercrop) was Aphis craccivora (Koch). Among the aphidophagous natural enemy guild, the major insect groups included coccinellids (C. septempunctata, Cheilomenes sexmaculatus, B. suturalis and I. cincta: Coccinellidae, Coleoptera); lygaeid bug (Geocoris sp.: Lygaeidae, Hemiptera,); rove beetle [Paederus fuscipes Curtis: Staphylindae, Coleoptera] and syrphid flies (Ischiodon sp.: Syrphidae, Diptera; being dominant). The seasonal mean population of aphids was higher during kharif season crop (369.09/plant) than during the summer season (291.26/plant). Likewise, the seasonal mean population of the natural enemy guild per plant was relatively more during kharif season being 8.56 (coccinellids), 3.76 (Geocoris sp.), 3.14 (P. fuscipes) and 2.41 (syrphid flies); whereas, in summer (jhaid) season the corresponding values were 7.78 (coccinellids), 3.60 (Geocoris sp.), 2.87 (P. fuscipes) and 1.89 (syrphid flies). Exclusion of the ground dwelling aphidophagous predators resulted into significantly more aphid predation (99.75%) than when aerial aphidophagous predators were excluded from access to aphid prey (89.38%). In the no exclusion treatment, where both types of predators (aerial and ground dwelling) had equal access to aphid prey, the decrease in aphid numbers was the maximum (100%). All the three coccinellid grubs and adult beetles consumed relatively more aphids at lower aphid densities (25, 50 and 75), significantly being the maximum at a prey density of 75. At higher aphid densities (100, 125 and 150) the consumption rates declined. The feeding behavior of coccinellids showed a sharp decline in percentage feeding with an increase in prey density for both adults and grubs.ennullThesis