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Nests are typically found in level, well-drained, hardened soil with little vegetation. They are made out of silt or loam soil as it retains moisture more effectively during drought periods (Roberts, 1973). Nest depth can be a minimum of 25 cm deep to a maximum of 75 cm deep depending on the colony size (Chandler, 1955). Nests can also be constructed in rotting wood, though the burrows and brood cells are irregular in shape (Richards & Packer, 1996).

Halictus ligatus belongs to the bee family Halictidae, which is characterized in part by a well-developed stigma, a single subantennal suture, and the first flagellar segment being much shorter than the scape. This family is also known to possess eusociality and underground nesting (Mitchener, 2007). The genus Halictus is differentiated from other genera by strong, opaque apical wing veins, and, typically, apical hair bands across the abdominal segments. The females of H. ligatus are easily differentiated from other females of the genus by a diagnostic postero-ventral genal tooth (Figure 1). Males can be differentiated from other males of the genus by long, suberect hairs on the second and third sterna (Roberts, 1973). Females are slightly larger than males, between 8 to 10 mm, while males are between 7 to 9 mm. Both sexes have no metallic tints to the body (Figures 2-3) (Ascher & Pickering, 2019).

Halictus ligatus is a primitively social bee with obvious size differences between the large queens and smaller workers (Roberts, 1973). They have an annual colony cycle in most regions, but in southern areas it can have multivoltine colony cycles, which means that broods can overlap (Packer & Gerd, 1987). Nests are founded in the spring by previously inseminated immature queens that emerge after overwintering; these are known as foundress females or queens. Some nests are haplometric and founded by a single queen, other nests are founded by two to six queens (Richards & Packer, 1998). Queens tend to return to the same nests yearly, and remodel the old nests. This is thought to increase the number of descendants a female has (Roberts, 1973). Queens live about one year and die by late August; their main role is nest defense, as well as to produce a first worker brood followed by a second brood of workers, gynes, and males (Chandler, 1955). The nests are comprised of a vertical main burrow that is excavated to produce a dirt mound outside the nest entrance, known as a tumuli. The tumuli symmetry can indicate interspecific differences; H. ligatus has a tumuli that is radially symmetrical around the burrow entrance (Roberts, 1973). Within the main burrow there are contiguous brood cells of varying size; the queen produces three to six brood cells, and when workers emerge they help construct more brood cells. Worker brood cells tend to be the same size as male brood cells, and there can be up to 40 brood cells in a nest. They are lined with a waxy material to protect the larvae (Chandler, 1955). After being laid within the cells, larvae emerge from eggs after four days. All larval instar stages take 21 days to develop, followed by a prepupal stage between one to four days, and a pupa stage ranging from eight to 13 days. Brood cell size, egg development time, adult size, and caste size vary based on the season and soil temperature (Chandler, 1955). When the first brood workers emerge, they help the queen create brood cells and collect provisions; the second brood females are made up of gynes and workers, and gynes will go forward to potentially be foundress females in the following year. When the males emerge in late summer, they live a maximum of two and a half months. They leave the nests and do not return, sleeping on flowers at night and copulating during the day. Males of H. ligatus have been known to attempt breeding with other species’ females in the Halictus and Lasioglossum genera (Chandler, 1955). In some subtropical populations, intraspecific cleptoparasitism has been identified within this species. The cuckoo caste individuals are larger than the typical worker but smaller than the queen (Packer, 1986).

Halictus ligatus is polylectic as a species but local populations obtain most of their pollen from the few flower species in the region of their nests. Foraging distances are never more than 150 m, as nests are often unguarded when the foundress leaves to forage (Chandler, 1955). The bees will not forage in poor weather conditions such as heavy rain, strong winds, or cool temperatures.

The North American range of Halictus ligatus is south of 50 degrees latitude to the West Indies and Colombia (Roberts, 1973). It also occurs in temperate regions from the Atlantic to Pacific Ocean to the southern Gulf of Mexico (Richards, 2004).