Pollen Resources Stored in Nests of Wild Bees Xylocopa ciliata Burmeister and Megachile pusilla Pérez (Hymenoptera: Anthophila) in a Temperate Grassland-Forest Matrix

VOSSLER F. G.

SOCIOBIOLOGY

CALIFORNIA STATE UNIV

Lugar: California; Año: 2018 vol. 65 p. 784 - 788

0361-6525

Pollen analysis was employed to study the diet composition of two wild bees in a patch of temperate grassland invaded by exotic plants. Thirty pollen types from 14 families and two unidentified types were present in the seven samples analyzed. The three samples from Megachile pusilla Pérez were composed of 100% Lotus glaber and the four samples from Xylocopa ciliata Burmeister of abundant pollen (˃5%) of Lotus glaber,Galega officinalis, Adesmia bicolor and type Senna-Chamaecrista (all Fabaceae). The latter resource likely foraged out of the park, which couldbe an evidence to support its pollen preference for Fabaceae. However, alarger number of samples is necessary to identify the specialization statusof X. ciliata. The preference for Lotus in this site was due to temporal specialization as M. pusilla was identified as polylectic in its origin area,and this could help to explain its effective naturalization in the New World and other areas of the Old World.