Figure 1

Exoneura rear their brood progressively in a communal undivided burrow, and food resources are shared among developing brood. (A) Xanthorrhoea minor flower scape with seed head; (B) X. minor flower scape without seed head, Exoneura nigrescens females burrow into the pithy interior (white arrow shows nest entrance) of scapes that have lost their seed heads; (C) Two E. nigrescens females at the bottom of the nest with a stockpile of eggs (early spring, before foraging and larval rearing has commenced); (D) Two E. nigrescens females at the bottom of the nest with larvae (late spring to early summer) when foraging has commenced; (E) Eggs and larvae (feeding on the yellow pollen, which also gives the larvae their yellow colour) at the bottom of a nest.