Nesting ecology of Megachile (Chrysosarus) catamarcensis Schrottky (Hymenoptera: Megachilidae), a Prosopis-specialist bee.

JUAN PABLO TORRETTA; SILVANA P. DURANTE; ALICIA M. BASILIO

JOURNAL OF APICULTURAL RESEARCH

INT BEE RESEARCH ASSOC

Año: 2014 vol. 53 p. 590 - 598

0021-8839

Nests of the leafcutting bee Megachile (Chrysosarus) catamarcensis Schrottky (Hymenoptera: Megachilidae) were obtained during a 24-month trap-nesting program in a xeric forest in the Province of La Pampa, Argentina. Nests were constructed in December and January; females made an average of 4.0 ± 2.2 cells, and used mud with flower petals and/or leaf pieces to build their nests. Provisions of cells were practically pure pollen mass of Proposis caldenia. Adult emergence showed a unimodal pattern, suggesting a univoltine life cycle. However, two individuals that emerged a month after the traps were collected indicate the existence of a small early-summer generation. This fact could be indicating that M. catamarcensis, in some years (warmer) or in some populations (at lower latitudes), could exhibit a bivoltine life cycle. Approximately 15.3% of all offspring failed to complete development to the adult stage, and an additional 13.9% were killed by natural enemies. These insects included diverse parasitic wasps (Chrysididae, Sapygidae, and Leucospidae), a cleptoparasite bee (Megachilidae: Coelioxys), and a bee fly (Bombyliidae: Antrhax).