We’ve had many more blue-banded bees and teddy-bear bees visiting our garden this year, mostly lured by the flowers on our rosemary bush. It was perhaps inevitable that the bees would be followed by some of their nest parasites, two of which I have never previously seen in our garden. The visits began with this Domino Cuckoo Bee (Thyreus lugubris), which I first saw on our tea-tree (Leptospermum) when it was in full bloom:
At the time, I was a little surprised to see it there. Domino cuckoo bees are parasitic on teddy-bear bees, which mostly ignore tea-trees. In fact, the only time I saw a teddy-bear around this particular tea-tree was when one cruised over to briefly inspect the cuckoo bee before flying off.
A little later on, another domino cuckoo bee visited the rosemary bush, allowing me to get a closer look at it. Domino cuckoo bees are so-called because of the black area running backwards from their mouth parts around their eyes to the back of the head, rather like a domino mask or a style of sunglasses. Like other cuckoo bees, their thorax extends back out in a protective plate over the junction between thorax and abdomen-- as can be seen here:
The black-and white pattern is clearly visible in the photos (sometimes the white markings may have a slight bluish sheen) as are the reflective blue highlights on the wings. . The white deposits on the top of its head and antennae are just a scattering of rosemary pollen. Domino cuckoo bee are not much smaller than teddy-bear bees, and quite stockily built. Like their teddy-bear hosts, domino cuckoo bees are “long-tongued”, with a long proboscis able to probe deeper flowers for nectar (visible in two of the previous photos).
To lay her eggs, a female domino cuckoo bee cruises around likely sites looking for a teddy-bear bee’s nest. When she finds one, she waits until its owner has left and then enters. Inside, she bites a hole in the cap of a freshly closed cell in the nest, inserts her abdomen, and lays her egg next to that of the teddy-bear bee. She then closes the breach and leaves. The cuckoo’s egg develops faster than the teddy-bear’s, and the hatched larva then eats the host’s egg before consuming the provisions laid down in the cell for it.
This cuckoo bee, however, seemed to be more curious about humans than bees. It eventually cruised over to have a look at me, hovering a couple of feet away for a couple of seconds before deciding I was harmless and heading off to more interesting pastures.