Sleeping Aggregation of Male Anthophorini Bees

Description:

At almost sunset I saw 3 male bees on the underside of a leaf about half a meter above the ground. Very hairy with orange and yellow hair. I tried to take their picture but they kept flying away and then returning after a minute or so. I decided to wait and as it got dark, more bees arrived. They were skittish until it was completely dark and by then there were 8 of them. Like other sleeping bees, they clamp onto a leaf vein with their mandibles, tuck their legs up against the body and go to sleep, all facing in the same direction. In the 3rd and 4th pictures you can see how they hold on to the leaf with only their mandibles and one bee has his feeding proboscis extended. This species has a white clypeus and white mandibles. Once they were asleep I was able to move the leaf around and they were so sound asleep, I think I could have even combed their hair and they wouldn't have noticed! Apidae: Apinae: Anthophorini.

Habitat:

Overgrown field, semi-urban area, San Cristobal de Las Casas, 2,200 meters.

Notes:

These bees are usually solitary. The females make nests in the ground. This is the first time I have seen a sleeping conglomerate of males. It would be fascinating to know how they all decide on a sleeping leaf. These are central american bees found only in the mountains between 2000 and 3000 meters. They are rarely seen and little is known of their biology. https://www.naturalista.mx/taxa/252513-D... http://moure.cria.org.br/catalogue?id=29... http://v3.boldsystems.org/index.php/Taxb... https://www.researchgate.net/publication.... See also this spotting by Celeste of another species of male bees from California, sleeping in a ball holding on to each other's legs! https://www.projectnoah.org/spottings/72....