Colony size of amazonian stingless bees and its assessment through intrinsic parameters

Abstract

Stingless bees live in populous colonies that vary in size from a few hundred individuals to tens of thousands, although information on actual colony size is limited. The objectives of this study were to determine the colony size of five Amazonian stingless bee species (Melipona flavolineata, Melipona fasciculata, Scaptotrigona aff. postica, Frieseomelitta longipes, and Plebeia minima), and to identify biological parameters that covary with colony size. The number of brood cells, adult bees, and food stocks were counted under laboratory conditions, alongside field assessments of egg-laying rate and external activity of adult workers. To identify covariates of colony size, the number of adult bees was regressed against the number of brood cells, egg-laying rate, external activity of adult workers, and food stocks, and the best candidate models were ranked using the Akaike Information Criterion. Mean (±s.d.) adult populations were: in M. flavolineata, 1046 ± 185; in M. fasciculata, 593 ± 300; in S. aff. postica, 7404 ± 1391; in F. longipes, 2425 ± 1000 and in P. minima, 405 ± 254. Thus, we showed that the external activity is the biological parameter, after the number of brood cells, that presents the best relationship with the number of adult bees, which can be easily evaluated in the field. Determining colony sizes using easily measurable biological parameters are important steps to understanding stingless bee’s life histories, ecology, and evolution, and to ease their keeping and utilization for pollination.