Parasite...

After a grey start, today turned out to be a real scorcher - and for once I've had a relatively lazy day - thank goodness! The high temperatures and sunshine meant that the garden was full of insects, particularly white butterflies and bumblebees. We have a lot of attractive nectar sources, the two current favourites being the marjoram and the globe thistles. This afternoon I spent some time watching and photographing the bumblebees -I confirmed that we have at least six species present, though the most frequent are the Buff-tailed Bumblebee Bombus terrestris and its social parasite the Vestal Cuckoo Bee Bombus vestalis, a male of which is shown here.

Cuckoo Bumblebees are identified by the lack of pollen baskets on the legs and they usually have tinted wings. Cuckoo bumbles tend to have less dense hair and their cuticles are thicker to withstand stinging by the host bumbles when they invade a colony. They are also rather lazy, being much less inclined to fly away when the photographer approaches, making them one of the easiest bees to capture, particularly as the males often congregate in gardens.

After emerging from hibernation during April the mated female of Bombus vestalis seeks out a small B. terrestris nest with a few workers. The female sneaks into the nest and hides while she acquires the nest scent. It may dominate, or kill, the host queen and takes over the egg laying for the colony. These eggs produce only new B. vestalis females and males, which take no part in the running of the colony, all work being done by the host workers. Hence, no need for pollen baskets - they have slaves to do all the work!