Correlation between Ocellar Size and the Foraging Activities of Bees (Hymenoptera; Apoidea)

Abstract

The occurrence of enlarged ocelli in nocturnal foraging bees has led to a quantitative study of the relation between ocellar size and foraging activity in a number of species of bees. The results show a negative correlation between ocellar size and the light intensity threshold of foraging. Ocelli also increase with head size, but this relationship is not as good a predictor of ocellar size as is the light intensity threshold. The results were all compatible with the observation that ocelli serve as enhancers of the sensitivity of the compound eyes.