These photos had the entomologists on Twitter getting excited when I first posted them Monday evening. Though I didn’t realise it at the time, what I was seeing was a parasite emerging from the back of the bee’s body. The parasite is a Stylops, a species that has a rather gruesome but incredibly fascinating lifestyle.
The female Stylops lives permanently in the body of its host, often, as here, one of the Andrena species of bee. Her head and thorax poke out of the bee’s abdomen so she can release male-attracting pheromones and mate. I managed to photograph these and blogged about them in April 2020 (Wild word: stylopised). When the resulting larvae emerge, they pop out onto flowers the bee is feeding on, so they can then hitch a ride with another bee, burrow into it, and start the process all over again.
Some of the Stylops larvae are male, with wings. They do not have mouth parts for feeding as their only purpose is to find a female and mate. It is one of those emerging winged males that can be seen in my photos and, apparently, this process is rarely seen. Unfortunately, someone came walking along the path where I was watching this bee and I had to move to one side to allow them to pass at a safe distance. When I looked back, the bee had disappeared.
If you want to read more about the Stylops, there’s an interesting article on the Royal Entomological Society website – the male Stylops has the distinction of appearing as the emblem on the society’s official seal and logo.