Montana Field Guide

Medium-sized, and fairly slow-flying relative to other bees in the Family: queens 17-18 mm in length, workers 11-12 mm, drones (males) 15-16 mm. Females (workers and to a much lesser extent queens) most often encountered, males (drones) rarely so; females with 10 flagellomeres (segments) in the flagellum of the antennae, males with 11 flagellomeres. Moderately hairy, especially on head and thorax; integument color highly variable from light orange to almost black, but usually with amber or yellowish areas on metasoma; hair present on compund eyes; mandibles lack teeth and have a spatulate, twisted appearance; hindleg tibial spurs absent, hindleg tibia and femur of workers broad, slightly concave, shiny and hairless (except fringe) forming a pollen basket (corbicula); hind legs often hang below body while in flight. Wings unique in North American bees north of Mexico; the marginal cell extremely long and extending almost to wing tip; stigma very small, the three submarginal cells are non-uniform in shape (Michener et al. 1994, Wilson and Carril 2016).

In our region, active March to September with peak activity May to July. Active season longer or shorter elsewhere in North America, with some active somewhere in North America every month of the year (Wilson and Carrill 2016).

A combination of fluffy hairs, presence of pollen basket (corbicula) on hindleg tibia of workers, lack of hindleg tibial spurs, twisted and spatulate mandibles, hairs in compound eyes, and wings with extremely long marginal cell extending nearly to wing tip, a very small stigma, and 3 non-uniform submarginal cells, distinguish Apis from other North and Central American bee genera (Michener et al. 1994, Wilson and Carril 2016).

Occurs in many habitats, including urban gardens and parks, railroad margins, prairie, grasslands, shrubland, fields, farmland, oak and mixed deciduous forests, dunes, semi-deserts, wetlands, riparian woodlands, and montane meadows (Visscher and Seeley 1982, Ratnieks et al. 1991, Baum et al. 2005, Wojcik et al. 2008, Molumby and Przybylowicz 2012). Colonies in artifical beehives occupy many kinds of commercial croplands (MacKenzie and Averill 1995, MacKenzie and Eickwort 1996, Calderone 2012).

Generalist, collecting pollen and nectar from nearly every type of flower, both native and domesticated (Wilson and Carril 2016).

Feral colonies nest usually above ground to at least 8 m height, but sometimes at ground level. Colonies use a diversity of cavities for nest sites including tree hollows, arboreal termite nests, caves and rock crevices, abandoned buildings, barrels, bird boxes, and rarely in unprotected locations on tree branches; commercial colonies established and maintained in artificial beehives (Seeley and Morse 1976, 1978; Seeley 1983, 2010; Ratnieks et al. 1991; Baum et al. 2005; Wilson and Carril 2016). Queens establish new colonies after mating with 12-15 drones and storing sperm for the remainder of their lives (queens may live 2-7 years). At peak egg production, queens lay 1500-2000 eggs per day, and about 150,000 in a summer. Eggs hatch in 3 days. Duration of larval and pupal stages depends on caste. Larval stage is 6 days for workers, 6.5 days for drones, 5.5 days for queens; pupal stage is 12 days for workers, 14.5 days for drones, 8 days for queens. Swarming by old queens and workers starts in early summer following production of 10-15 new queens (Seeley 2010, Wilson and Carril 2016). Workers survive only a few months, drones about 3 months; foraging workers tend to die before reaching senescence, with a median lifespan of 7 days (range = 2-17 days). In some colonies, a very small fraction of drones are produced from eggs laid by workers (Visscher 1989, Visscher and Dukas 1997, Wilson and Carril 2016).