Lelaps sp. (A Parasitic Wasp)

An unforeseen side-effect of picking up macro photography has been that, every time I turn around, I discover an entirely new universe. Before I started trying to identify my tiny photo subjects, I had absolutely no idea how many of the miscellaneous little black “flies” zooming around were actually tiny, parasitic wasps. And I do mean tiny — the little lady above is barely visible with the naked eye, about 3mm long.

Parasitism is a profitable venture. Other insects and animals engage in it, but, as a taxon, wasps have gone for it in a big way. Technically, most of them have gone for parasitoidism — they not only steal nutrients, etc., from their host, they kill it when they’re done. These terrifying little wasps are responsible for keeping down the populations of various moths, beetles, spiders, etc. There are so many species. Some parasitoid wasps parasitize other parasitoid wasps.

As a group, the Parasitica [parasitoid wasps] run the gamut of a remarkable diversity of life cycle characteristics. The idiobionts develop relatively quickly, usually killing the hosts at a relatively earlier stage of host development than the koinobionts. Koinobiont parasitoids undergo a quiescent period during the egg or larval stage, allowing the host to develop to a later (and usually larger) stage of development before killing it. Ectoparasitoid adult females deposit the egg or eggs outside the body of the host, while endoparasitoid females inject the egg or eggs into the host’s body.

Egg-larval parasitoids are those in which the female parasitoid deposits her egg in the egg stage of the host, and the parasitoid completes its larval development in the host larva, killing it at that stage. In larval parasitoids, the egg is deposited on, near, or in the host larva, and completes its development there, killing the host larva. There also may be egg-pupal, larval-pupal, and pupal parasitoids.

Some parasitoids lay only one egg per host (solitary parasitoids) while others lay several eggs per host (gregarious parasitoids). In polyembryonic parasitoids one egg develops into many parasitoid larvae. Hyperparasitoids are those that attack another parasitoid developing in the primary host. Superparasitism is when two parasitoid larvae of the same species parasitize the same host. Multiparasitism occurs when parasitoids of more than 1 species develop in the same host; of course there may also be competition to the death in both of these cases.

And then there are parasitoid wasps that attack adult insects and spiders. The fun never ends.


That huge pointy thing on the back there? It’s an ovipositor, but that doesn’t mean it’s not designed to be inserted…forcefully…into something like a cocoon (or a caterpillar) to get an egg way down in there.

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