Romance, Wool Carder Bee-Style

As I have occasionally let slip in previous posts, I have a soft spot for some of our most reviled non-native species and tend to cast an eye in their direction frequently when walking along the trail. The bright yellow flowers of low-growing Birdsfoot Trefoil (Lotus corniculatus) often grab my attention, and I enjoy seeing some of the small bees (generally also non-native) that can be seen hard at work prying into the tight petals of the flowers ins search of nectar and pollen.

Dropping down to take a few shots of what appeared to be a wool carder bee (possibly Anthidium oblongatum, Oblong Wool Carder), I smiled to myself as the green-eyed bee moved from flower to flower in the small clump of Trefoil.

Suddenly, another insect made a beeline [sorry] for the first. seemingly dropping from the sky and zeroing in directly on the first bee as its head was buried in a flower. The encroacher clasped its back and held it immobile. Was this a bee assault? A murder in progress?

Oh wait. They seemed to be the same species and--what's this? A little contact at the tips of the abdomens? It appears that a male bee, unceremoniously and without the slightest attempt at woo, saw an opportunity and took it. Surprised but unabashed, I continued watching as the pair remained immobile for 20 or 30 seconds, save for the male's antennae.

I left the encounter a little unsettled at the odd and seemingly hostile scene I had witnessed. The female bee gets no say in the matter? No displays, no demonstrations of fitness or other performance from the male to earn the female's favor?

This is, apparently, a common tactic among wool carder bees. Males are very territorial and will patrol their patch of flowers, driving out other male wool carders and sometimes even other species. Females tolerate what looks like a brazen assault in exchange for access to these high-quality foraging areas where they don't have to compete as much with other bees snaffling up all the pollen. Males and females will mate several times with multiple partners over the course of their lives; with the last male to mate with a female being the most likely to win out in the fertilization game.

Because of this mating system, male wool carder bees are generally larger than females, in contrast to the size difference in the opposite direction for other types of bees. Smaller males may still deploy sneak-matings with females successfully without holding territory of their own, though they find less opportunity to do so.