Egg-production in the Mustard Beetle, Phaedon cochleariae (F.) in Relation to Diets of Mineral-deficient Leaves

Abstract

Studies have been made of the effect of feeding adults of the Mustard Beetle, Phaedon cochleariae (F.), on diets of watercress leaves (Nasturtium officinale) taken from plants grown in water cultures of known nutrient composition.Significant reductions in egg-production were recorded when individual beetles were supplied with leaves deficient in nitrogen, phosphorus, potassium or iron, as compared with the egg-production of the same beetles supplied with leaves from plants grown in complete-nutrient solution.A marked alteration in the rate of egg-production occurred within two or three days of changing the diet from “complete-nutrient” leaves to mineral-deficient leaves or vice versa.