Impact of certain corn cultivars on some ological parameters of Rhopalosiphum maidis (Fitch) tera: Aphididae)

The development, survival rate, reproduction and biological parameters of the corn leaf aphid, Rhopalosiphum maidis (Fitch), on five corn cultivars were evaluated at 25°C under laboratory conditions. The corn leaf aphid had a longer nymphal developmental time of 4.99, 4.98, 4.73, 4.46, and5.60 day of Ada9516, K. Arifiye, PrimerG626, Pegaso and TTM815, respectively. The corn leaf aphid reared on K. Arifiye had the highest fecundity (69.65 offspring/aphid). The lower percentage survivalrates were observed on TTM815 than that of the others. Net reproductive rate (Ro) was lowest (67.35 offspring/aphid/generation) on TTM815. The intrinsic rate of increase (rm) was lower on TTM815 than that of the other corn cultivars. TTM815 showed resistance to the pest