Preferred Grain Quantity and Insect Density for Maize Weevil (Coleoptera: Curculionidae) Interaction Studies

Abstract

An experiment was conducted to investigate main and interactive effects of maize weevil (MW), Sitophilus zeamais Motschulsky, density, maize, Zea mays L., kernel density, and oviposition period on MW oviposition, progeny production, and maize damage, to determine the smallest number of maize kernels and MW and minimum oviposition period necessary to optimize MW responses in factorial experiments. Two maize genotypes were also included to investigate a possible genotype influence on selected MW and maize densities and length of oviposition period. Four female/male densities, two maize genotypes (one susceptible and one resistant to MW feeding), three oviposition periods, and four kernel densities were tested. Results confirmed that weevils should be held on ≥40 kernels to obtain the largest response in eggs and progeny per female and grain weight loss regardless of weevil density. However, only two females and one male per vial were necessary for determining effect of maize kernel density, genotype, and length of oviposition period on MW biology. At least six females and three males per vial were needed to determine total amount of damage to maize. It was determined that weevils should be allowed to oviposit for ≥21 d.