WITHIN-COLONY SIZE VARIATION OF FORAGERS AND POLLEN LOAD-CAPACITY IN THE STINGLESS BEE MELIPONA-QUADRIFASCIATA-ANTHIDIOIDES LEPELETIER (APIDAE, HYMENOPTERA)

Within-nest worker size variation in the eusocial stingless bees is a contingent phe nomenon of unknown adaptive value We assume that the ma gnitude of variation represents a compromise between a minimum populat ion of foragers and foraging efficiency at colony level. In Melipona q uadrifasciata, worker size was found to vary according to colony condi tions, and the pollen carrying efficiency of an individual was related to its size. On average, the foragers from a weak colony are smaller and are able to carry greater amounts of pollen per unity of body weig ht ('load capacity') than the larger foragers from a strong colony. Th e allometric variation of the corbicula (the pollen carrying structure in the hind tibia) contributes to the observed decrease in pollen loa d capacity with increased body size. By higher pollen intake per worke r, the colonies with smaller bees could increasing the rate of brood p roduction and colony population recovery after population crashes. (C) Inra/DIB/AGIB/Elsevier, Paris.