ISOLATION AND CHARACTERIZATION OF CERTAIN INSECT SECRETIONS

Food insects, existent already in early ages, have found fertile breeding grounds in certain modern food industries. As a consequence, some of man's foodstuffs are contaminated with considerable amounts of insect debris. The problem has generally been recognized in terms of its aesthetic damage. This view is presently extended to include consideration of possible harmful effects of the beetle contaminants. Most insects of stored food secrete pungent fluids of benzoquinones, i.e., well-known toxic chemicals. A method for the isolation of the quinones is described. It comprises freeze-killing and high-speed homogenizing of the beetles in cooled isopentane. The active material is recovered by controlled sublimation. Polarographic analysis shows that the method is quantitative and supplies substantially pure quinone. Quinones thus obtained from flour beetles Triboluim have conspicious effects: (a) The growth of Microsporum gypseum accelerates in the presence of minute quantities (10⁻⁵ M) of the secretion; larger amounts of the material (10⁻³ M) block the development of the fungus; (b) Exploratory studies indicate that the beetle quinones provoke malignant lesions in rats; (c) Applied 10 immature stages of Tribolium, the fluids produce monstrous deformities in the emerging adult insects.