Nesting site selection by wasps in the Guianese rain forest

Abstract

In the edge of the rain forests in French Guiana, the large leaves of young Astrocaryum sciophilum, a palm tree with long thin spines (up to 9 cm) along their central vein, shelter significantly more mason as well as social wasps' nests, than leaves of other plants. Other such plants include older conspecific individuals with spines, but compound leaves, and young Bactris simplifrons, a palm tree with similar leaves but devoid of spines. The choice of these leaves is due to the association of two factors: (1) these large leaves with a concave underside offer good protection against inclement weather, and (2) the spines on which the wasps' nests are anchored serve as "acquired pedicels", offering protection against ant predation. As a consequence, the wasps' nests are found under these leaves in both inter- and intraspecific clusters.