The H. sexcinctus can be easily confused with the closely related species, Halictus scabiosae, due to very similar morphological features.
H. sexcinctus show a social polymorphism in which different colonies can exhibit solitary, communal, or eusocial structure.
[1] Halictus sexcinctus is a species of ground-nesting bees, previously thought to only exhibit solitary behavior.
[4] Males also have slimmer bodies than females and their antennae are longer with a slightly different coloration.
H. sexcinctus differs from H. scabiosae in that males have longer, reddish antennae, and females lack the basal hair bands on tergites 2-4.
[8] In eusocial nests, queens show aggressive behavior, and a fight to the death can occur if another female tries to usurp the foundress.
However, in communal nests, aggression between females is little to non-existent, and foundresses will continuously join the colony during the founding period from late May to early June.
Depending upon the social organization of a particular nest, female workers show a range of behavior, from complete selfishness to eusocial helping.
Phylogenetic analysis suggests that H. sexcinctus has a social ancestor, and that solitary populations are an example of evolutionary reversal.
Their nests consist of a main tunnel dug diagonally into the ground, with several short side chambers off of it leading to brood cells.
In this Greek population, only about 50% of foundresses survived to the eclosion of the first brood, so it is probably necessary that workers lay many of the second-brood eggs.
Communal colonies do not have castes, but rather multiple females of the same generation work together with relatively little reproductive skew and aggression.
[6] It is fairly unusual to find both communal and eusocial behavior exhibited by the same species outside of the halictine bees.
[2] In all socialites, foundresses tend to show higher levels of ovarian development than workers and are also more likely to mate.
Compared to other Halictus species, H. sexcinctus has a high rate of worker ovarian development.
This suggests that infertile workers are more altruistic in order to gain inclusive fitness through kin selection, due to the fact that they are unable to produce their own offspring.
[9] A new species of mites, Histiostoma halicticola, was discovered to parasitize H. sexcinctus in a study by Fain et al.
The bees harboring these mites were found in the Döberitzer Heide nature reserve, nearby Berlin, Germany.
Males lack this particular furrow, so the mites are found on the smooth, concave ventral surface of the thorax between the coxae.
Antimicrobial peptides (AMPs) are commonly found in the venom of arthropods, and these proteins function by breaking up bacterial cell membranes.
A substance that damages human red blood cells will be less valuable as an antibiotic for obvious reasons.
These new proteins showed effective antimicrobial activity against four strains of bacteria (B. subtilis, S. aureus, E. coli, and P. aeruginosa) and a yeast pathogen (C. albicans).
However, when their structures were modified a few analogs with slightly lower hemolytic activity were discovered, meriting further study.
However, because these communal and eusocial strategies exist separately without transition in this species, the data do not support that theory.