Leaf foraging sources of leafcutter bees in a tropical environment: implications for conservation

Abstract

Leafcutter bees collect leaf discs to encase brood cells. However, our understanding of their use ofplants as nesting resources, which is critical for their conservation, is poor. We followed plants and observed beescutting leaves to understand the leaf and plant traits of the leaf forage plants ofMegachilespp. We studied whetherthe leaf size explains the cut size and the number of cuts in the leaves. The bees collected leaves from 59 species, 49genera and 25 families of plants of various habits. Plant habit, leaf morphotype and leaf size did not influence leafchoice by the bees. Of the plants surveyed, 45.22% had the distinguishable cutting marks. About 63% and 98% ofthe plants the bees used are native to the region and to the tropical southern hemisphere, respectively. Bees selectedleaves over an extreme size range, and the leaf size predicted the number of cuts on a leaf. Comparing our resultswith other studies, we conclude that the leafcutter bees’selection of plants is adapted to the local environment