Tag: cuckoo bee

Bug of the Week: Bees in Desert Marigolds

Spring is dragging along this year because we’ve had cool weather longer than usual. That’s a good thing!

But is has also meant some insects are behind their usual schedule.

solitary beesTake the solitary bees, like the digger and sweat bees. Usually we have clouds of tiny bees visiting flowers in March. This year they have been delayed.

The cuckoo bee can be an indicator. I watch the desert marigolds for them every year. This is a photograph of the first one I’ve spotted this year and it is April 15, 2020. In past years, we’ve seen them in February and March.

Taking photographs can be a way of keeping records of when certain events occur.

Do you have any insects that you look for year after year?

Bug of the Week: Cuckoo Bees

After doing Bug of the Week for so many years, it can be difficult to find something new. This week I was lucky.


Although it looks quite a bit like a sand wasp, this is a new kind of cuckoo bee. It might be Triepeolus sp. (like this one).


Look at the tongue (proboscis) that it using to suck up nectar.


We have seen another cuckoo bee in our yard before, Xeromelecta californica (previous post).

Named after cuckoo birds, cuckoo bees lay their eggs in the nests of other kinds of bees or sometimes wasps, depending on the species. They don’t build their own nests and lack pollen baskets for collecting pollen. It’s not a warm and fuzzy lifestyle, but that’s nature for you.

Bug of the Week: A Cuckoo Bee

We have been seeing this curious insect every year in February and March in our spring wildflowers.

cuckoo-bee-2015(February 18, 2015)

It regularly visits the desert marigolds.

2009-cuckoo-bee-xeromecta-californica-male(March 4, 2009)

Although it looks like a wasp or maybe a flower fly, it is a bee. In fact, it is a cuckoo bee, Xeromelecta californica.

What is a cuckoo bee?

Instead of making a nest and gathering pollen of their own, cuckoo bees sneak into the nests made and provisioned by digger bees (Anthophora sp.. especially Anthrophora urbana.) The females kill the eggs the mother digger bee laid and lay their own eggs on the food instead. The cuckoo bees then fly away and the nest eventually produces cuckoo bees rather than digger bees.

Ah, the drama that unfolds in one small suburban yard.

Have you ever discovered a cuckoo bee? What kinds are found where you live?