Linoleic Acid, α-Tocopherol and other Fat-Soluble Substances as Nutritional Factors for Insects

Abstract

IT is now well established that, for growth, insects require a sterol in the diet. We have now established the need for other fat-soluble factors in experiments on the nutrition of a number of insects. Thus the caterpillars of Ephestia kuehniella grow very badly on an artificial diet consisting of casein, glucose, yeast, cholesterol, salt mixture and water. A few reach the pupal stage after a long time, but moths invariably fail to emerge. With Ephestia elutella, growth is relatively better on such a diet; but again, the moth fails to emerge. This deficiency is entirely overcome by adding wheat germ oil in quantities of approximately ½–1 per cent of the diet.