Are Yeasts Present in Adult Worker Honey Bees1 as a Consequence of Stress?2,3

For several years I have been examining the intestinal microflora of healthy adult worker honey bees, Apis mellifera L. Of special interest was the fact that yeasts were rarely isolated from bee guts, although filamentous fungi were usually found (Gilliam and Prest 1972). This observation was surprising, since yeasts are abundant in nectar and honey. Also, yeasts have been isolated from the honey stomach and midgut of honey bees (Batra et al. 1973) and from intestinal homogenates (Egorova and Bab'eva 1967).