Oviposition performance of Sitophilus zeamais Motsch. (Coleoptera: Curculionidae) on resistant and susceptible maize accessions

Oviposition of the maize weevil, Sitophilus zeamais Motsch., was studied in resistant and susceptible maize under different environmental conditions. At 67% RH and 27°C, the females oviposited more eggs in the floury-susceptibles ANC-585 and AREQ-077 than in the resistant CAJ-208 and SMTI-057. Oviposition in the hybrid dent, Pioneer® 3377, was intermediate. More eggs were placed in the endosperm than in the germ or germ-endosperm interface. There was significant interaction between types of maize and kernel areas. The number of kernels left without eggs after an oviposition period of 96 hr was recorded at 67% RH in single and mixed maize cultures and at 50%, 75% and 85% RH in single cultures. The females rejected the resistant CAJ-208 kernels 4.5 times more than the susceptible Pioneer® 3377 and 3.8 times more than AREQ-077. In mixed cultures, none of the Pioneer® 3377 kernels, 2.5% of the susceptible ANC-522 kernels, and 12.5% of the resistant CAJ-208 kernels were left uninfested. At 50% RH, the females failed to oviposit on 20 times more kernels of all accessions than at 75% RH, and 60 times more than at 85% RH.