A92. Packer, L., A.-I. Gravel, and G. LeBuhn. 2007. Phenology and social organization of Halictus (Seladonia) tripartitus (Hymenoptera: Halictidae). Journal of Hymenoptera Research. 16:281-292.
Abstract: We present data on the social biology of Halictus (Seladonia) tripartitus Cockerell based upon samples from California. This bee is at least partially eusocial and overwintered gynes and first brood workers differed in size by 5.14%. 35.5% of the first brood workers had developed ovaries, 11.2% had ovaries with the equivalent of at least one fully developed oocyte but less than 14% were mated. In July and August, female reproductive options seemed highly variable: approximately 55% were sterile workers, 2.6% had better developed ovaries than spring foundresses and over 20% had at least the equivalent of one fully developed oocyte whereas an additional 20-30% may have been capable of overwintering as gynes. Ovarially developed workers were larger than those that remained sterile. Sixteen to 28% of the late summer workers were mated, but mated individuals were not more likely to have developed ovaries or to be larger than unmated bees. We discuss these findings in the light of the climate of the study area and compare this species with other members of its subgenus.