An absence of enzyme variability within two species of Trigona (Hymenoptera)

New South Wales and southern Queensland populations of two eusocial, stingless bees, (Trigona carbonaria and T. australis) were examined for enzyme variation at 20 gene loci. The high level of interspecific variation (60 per cent fixed gene difference) contrasted sharply with the absence of intraspecific variation over a 1400 km range. Factors which might underlie this effect such as reduced heterozygote advantage, inbreeding and low environmental variability within and between nests are discussed.