Morphological constraints and nectar robbing in three andean bumble bee species (hymenoptera, apidae, bombini)

We report differences in foraging behavior of three Andean bumblebee species onflowers of Digitalis purpurea (Scrophulariaceae). Bombus atratus was a potentialpollinator while B. hortulanus and B. rubicundus collected nectar by robbing throughholes. We attribute behavioral differences to physical co...