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Our discovery this week is due to some photogenic wild sunflowers.

sunflower-1I was taking a few photographs, when...

sunflower-flying-wasp-18what is that tiny insect flying by?

sunflower-wasp-flying-0006There it is again. Can you spot it?

little-wasp-on-sunflower-13To give you scale, this is what it looks like on a sunflower petal (actually ray flower).

wasp-on-sunflower-petal-40Talk about tiny! It is a parasitic wasp (Pteromalidae).

Why are tiny wasps hovering around a sunflower? It is possible that they are parasites of insects that visit sunflowers. Many species are parasites of insect eggs. It is also possible the wasps are feeding on nectar, although I saw no evidence of feeding. They also could be males waiting for females to visit.

What do you think these tiny wasps are doing?

1

Hey, what is that insect on the sunflower leaf?

good-parasitoid-wasp-perspective

The one amongst all those aphids.

parasitoid-wasp-closer

Look at those stripy back legs!

parasitic-wasp-222

This is a parasitic wasp, or more technically a parasitoid wasp. Parasitoid wasps lay their eggs in other insects. The wasp larvae feed and complete their life cycle inside their host.

I think this wasp is rather large to have completed its development within an aphid, don't you? It is more likely to use something larger, such as caterpillars, as hosts.

After a bit of research I found out it is Diplazon laetatorius, a parasite of hover flies. Why is it hanging around aphids?

The larvae of hover or flower flies feed on aphids (see this previous post). So, this parasitoid of hover flies is sitting in the food of its host. Talk about sly!

Have you ever seen parasitoid wasps on plants?

tiny-wasp

Can you spot the wasp in this photograph?

Did you know that wasps come in all sizes, including tinier than an aphid?

The yellow oleander aphids return each year about this time and feed on our desert milkweed. In turn, a number of other organisms use them for food, such as the tiny wasps.