Studies on the Symbiotic Yeasts of Two Insect Species, Lasioderma Serricorne F. And Stegobium Paniceum L

The shape and appearance of the yeast-like symbionts of Lasioderma serricorne F. and Stegobium paniceum L. have been described. The symbionts have been cultured in Hansen's solutions and on an agar medium.2. The larvae of both species are relatively little affected by the absence of certain vitamins of the B-complex. After elimination of the symbionts these vitamins become absolutely necessary.3. Sterilized larvae of either species have been successfully re-infected with the symbionts of the other host, which then retain their peculiar shape and mode of action.4. Cultured symbionts exert the same growth promoting effect as dried brewers yeast when added to the food.5. The symbionts are also sources of sterols for their hosts.