Evaluation of EPN formulations their shelf life and efficacy of heterorhabditis indica RCR Heterorhabditidae Nematoda against economically important insect pests

Abstract

Investigations were carried out on shelf life of different nematode formulations of newlinelocally isolated EPN Heterorhabditis indica (RCR), to standardize the density and temperature newlinefor long storage period and bio efficacy of different nematode formulations against newlineeconomically important insect pests was undertaken under laboratory and field conditions newlineduring 2005-08 at the Department of Entomology, College of Agriculture, Raichur. newlineThe studies revealed that in aqueous formulation the best combination of newlinetemperature, population density and duration of storage was 10°C, 10000 IJs/ml and 120 newlinedays of storage period, respectively. The corresponding values for talc formulation found to newlinebe 20ºC, 10000 IJs/ml and 120 days of storage period. Similar studies in sponge and alginate newlineformulations also showed encouraging results. newlineThe production and duration of emergence studies revealed that one to four week old newlineIJs stored at 10 and 15 ºC was found to be most appropriate for maximum production in newlineaqueous and alginate formulations and time taken for emergence was shorter. newlineAmong the different formulations aqueous formulation revealed maximum larval newlinemortality of H.armigera when exposed to 90 days old IJs stored at lower temperatures. newlineMaximum larval mortality of S. litura was recorded from aqueous (spray) and alginate (bait) newlineformulations when exposed to 30, 60 and 90 days old IJs stored at lower temperatures. newlineEfficacy of different nematode formulations evaluated against H. armigera in chickpea newlineecosystem revealed that the plots treated with talc formulation at 8000 and 10,000 IJs/g newlinerecorded maximum yield with minimum pod damage. newlineAmong the various formulations evaluated against C. partellus infesting sorghum, the newlineaqueous form of whorl application was found to be superior followed by talc and spray form. newline