Nest structures and notes on the social behavior of Augochlora amphitrite (Schrottky) Hymenoptera.

DALMAZZO, MILAGROS & ROIG-ALSINA, ARTURO

JOURNAL OF HYMENOPTERA RESEARCH

INT SOC HYMENOPTERISTS

Año: 2012 vol. 26 p. 17 - 29

1070-9428

Abstract The nesting biology of Augochlora (Augochlora) amphitrite (Schrottky) at a natural reservation in the Province of Buenos Aires, Argentina, is described. The species nests in decaying wood. Two types of nest architecture were found, which differed according to the substrate where they were built, either soft or hard wood. Nests in soft wood had the cells grouped in clusters surrounded by a cavity, and supported by a varying number of pillars. Nests constructed on the decomposing parts of cracks of hard wood had the cells constructed against the walls, without any pillars or surrounding cavity. Cells of both types of nests were oriented in all directions, without any detectable pattern. Measurements and characteristics of the nests are tabulated and compared to those known for other species of Augochlora s. str. Probably all species of Augoghlora s. str. are able to construct well defined clusters, given that an unconstrained substrate is available, as it is the case in A. pura and A. amphitrite. Behavioral observations of active nests are indicative of a social division of tasks in A. amphitrite. Such observations include nests with several females, some of which were never observed outside the nests, females with different degrees of wear and of ovary development, and at least one female that actively collected pollen which had much worn mandibles and wings, and undeveloped ovaries, all characteristics of the worker caste in social halictids.