Relative Susceptibility of Groundnut Cultivars to Different Population Densities of the Leaf Miner, Aproaerema modicella Deventer

Studies undertaken in glass house and screen house to identify optimum conditions for oviposition by groundnut leaf miner (GLM) indicated that leaf miner laid more eggs in choice conditions on different groundnut cultivars when compared to non-choice conditions. 10 pairs of adults/cage in choice conditions was found to give observable (though statistically non significant) differences in ovipositional preference/non-preference of cultivars for the insect. In no choice conditions, GLM oviposited more on ICG 221, ICGS 44, and NC Ac 17090 when compared to cvs. ICGV 86031 and ICG (FDRS) 10. Infestation was found to be density dependant so that screening for high levels of resistance (antibiosis) can be done with higher densities of insects/cage. On the basis of mean pupal weight, the susceptible cultivar ICG 221 had significantly higher pupal mass when compared to the moderately resistant cultivars i.e., ICGV 86031, ICG(FDRS) 10 and NC Ac 17090. In general, higher infestation reduced the average pupal mass on all cvs. indicating the limited availability of plant material to individual larvae at higher infestation.