Quote from The Australian Native Bee Book – page 28 “the males collected outside the nest may be smeared with resin. This may serve some function during courtship behaviour”.
Photos of males roosting on branches. You can see resin on their legs and the branch has also been coated in resin.
Read more about – The secret life of males – Male reproductive behaviour in stingless bees
You might notice congregations of stingless bees on fence wire and tree branches. Research done by Francisco Garcia found that male bees leave the colony once they reach sexual maturity and it’s their mission to find a virgin queen from another colony to mate with. Francisco checked DNA from colonies in surrounding areas and found the male bee can travel anywhere from a few hundred metres up to 20km to mate. The congregations in your yard may actually consist of hundreds of unrelated colonies. It’s thought that the male bees are attracted by pheromones from the virgin queen and could also be attracted to congregations of other males.
Below: Blue Banded Bees
Another native Australian bee is the Blue Banded Bee. These are males roosting on thin twigs overnight. The females make their nests in the ground. Most solitary bees are ground nesting.