The Toxicity of Corn Germ to the Meal Worm, Tenebrio Molitor

Publisher Website
Google Scholar
Abstract
The larva of the mealworm, Tenebrio molitor, has been shown to undergo a growth inhibition following the inclusion of unheated corn germ or whole ground corn in basal diets containing high levels of the known growth factors for this organism. Additions of lysine, trypotphan and high quality protein failed to improve the rate of larval development, although autoclaving the germ or whole maize resulted in a marked increase in the rate of weight gain. Corn from which the germ was removed by manual dissection was shown to be of high nutritive value to the insect after supplementation with lysine and tryptophan. The addition of 3 to 7% raw de-fatted germ to a variety of diets of high food value to the mealworm produced marked reductions in the growth rate. Extraction of unheated corn germ with 0.25 N H2SO4 resulted in the concentration of a non-dialyzable, heat labile toxic substance which inhibited larval growth at the 1.6% level. The relation of the corn germ inhibitor to the nutrition of vertebrates and insects is discussed.