Nesting behaviour of Centris (Heterocentris) analis (Fabricius) in southeastern Brazil (Hymenoptera, Apidae, Centridini)

The nesting behaviour of Centris analis was studied on the campus of the University of Sao Paulo-Ribeirao Preto, SP, Brazil. The bees nested in trap-nests made with black cardboard, measuring 5.8 cm in length and 0.6 cm in internal diameter. The bees constructed their nests with plant material and an oily substance. Completed nests had 1 to 4 cells arranged in a linear series, usually followed by an empty vestibular cell. Cells provisioned with a greater number of pollen trips were more likely to produce females than males. The innermost cells of the nests produced females, and the outermost cells produced males. Nests were parasitized by wasp, Leucospis cayennensis, and by bees, Coelioxys sp. and Mesocheira bicolor. Intraspecific parasitism was observed on 10 occasions. Although the factors inducing C. analis females to act parasitically are not known, the nest-site availability and food availability observed in this study apparently did not influence that behaviour.