[4] The genus name Halictus refers to a group of sweat bees of the family Halictidae and order Hymenoptera known for their eusocial behavior and underground nesting.

These individuals are easily differentiated from those of the closely related Lasioglossum by the presence of their pale fasciae hair bands on the posterior margins of the metasomal terga.

[7] In addition, the species is predominantly black or brown-black and lacks the faint metallic tints found in bees of the Seladonia subgenus.

[7] For H. ligatus, similar to other eusocial halictids, the differences in reproductive strategies among females correlate with distinctions in body size and appearance.

[8] For instance foundresses, or queens, tend to be large-bodied females in order to maximize energetic reserves, thereby enabling them to overwinter, establish nests, and reproduce independently.

[8] Halictus ligatus is one of the most abundant and readily identifiable bees in North America, encompassing a wide range of aridities and altitudes.

In north temperate regions, H, ligatus has an annual colony cycle similar to that which is found in almost all other halictines, or social sweat bees, during which the cold winter ensures several months of complete inactivity during which only young gynes survive.

As a result, bees collected towards the end of the colony cycle display a larger proportion of males and young gynes than earlier samples.

[13] In addition, individuals in this region experience markedly reduced reproductive division of labor as compared to those who participate in the annual colony cycle.

[13] The vast range of distribution contributes to the variations in behavior and dominance hierarchy observed for individuals of the species living in different environments.

[11] In fact, habitats experiencing adverse conditions caused by excessive rainfall resulted in poor brood survival, production of fewer workers, and queen-dominated oviposition.

[14] For instance, females that emerge in mid-summer that are small, have few or no fat stores, and whose nesting includes a larger queen tend to develop as workers who assist their mothers to raise the second, reproductive brood.

[14] For colonies in which there exist multiple foundress associations, subordinates continue to forage while their social role more closely resembles that of a mid-summer worker as opposed to a haplometrotic spring queen.

[14] H. ligatus worker individuals experience varying levels of eusocial behavior and colony organization depending on the environmental conditions.

[11] H. ligatus is a primitively eusocial species meaning that there is suppression of ovarian development in female workers by aggressive behavior of the queen.

[15] The inhibition of ovarian development is accomplished by phermonal secretions and aggressive acts by the queen, who is trying to maintain herself as the sole egg layer.

[16] When climate is harsh or breeding season becomes short, some members of the colony may become socially polymorphic and revert to a solitary lifestyle,[17] an adaptation to varying environmental conditions.

[3] Due to the correlation between female body size and role in the colony, it becomes evident that larval diet plays an integral part in caste differentiation and sociality for H.

[8] In fact, the mother bee is often seen limiting the amount of resources and nutritious intake she provides to her offspring so that they are forced to develop into small and lean females.

[8] This deliberate behavior ensures that these daughters are suitable for their roles as helpers, as a result of their incapability to perform independent reproduction.

[19] Within a single foundress colony the average relatedness is 0.5, implying that the queens will use equal amounts of sperm from two males that are not related.

[20] However, size of provision masses does not vary with pollen type, indicating that foragers are not able to recognize protein content differences.

[10] H. ligatus are ectothermic organisms meaning that both food availability and temperature have significant effects on development and body size.