Development of Sitophilus zeamais Motschulsky,in maize kernels and pellets made from maize kernel fractions

As a means of studying certain aspects of resistance of maize varieties to Sitophilus zeamais, various types of pellets were prepared using ground maize and compared with whole, pericarpless, and germless kernels. Numbers of weevil progeny (from six females and three males, and usually a 7-day oviposition period) were greatest in pellets made of flour moistened with water containing agar. More progeny was produced in pellets than in whole kernels. Damaged kernels (hot-water treated, pericarpless, germless) were more susceptible than undamaged kernels and fewer weevil progeny were produced in pellets made of germless kernels than from pellets of whole kernels. Additions of small amounts of extra germ tissue to whole maize flour enhanced the susceptibility of pellets to the weevil, but adding larger amounts of germ of pericarp reduced progeny number, weight and developmental speed.