Posted in Creatures

green stink bugs and feather-legged flies

I recently found a green stink bug in our yard.  These can be pesky for a garden.

I almost didn't see this, it blends so well.
A pest to seeds and growing crops just hanging out on a berry cane today.

However, I also know I have spotted at least one Feather-legged Fly, also known as tachinids.  These are predatory toward the green stink bugs in that their young use them as hosts.  That makes them protelean parasitoids.  [Image Credit: Marvin Smithoriginally posted to Flickr as Feather-legged Fly (Trichopoda pennipes)]

The white part in the red circle might be an egg case.If you blow up my stink bug image, you can see an oblong white spot near one of its eyes.  I can’t tell for certain given the image quality, but there is a chance that this is a developing egg of the feather-legged fly because that’s where they tend to lay them, along the back of the head.

So although I was tempted to squish this one, it’s the only one I’ve seen so far this year.  I’m also even more glad now because I saw the possible signs of the parasitoid on it when I looked at the images I had snapped today.  In my mind, if it is an egg, that means the tachinids are doing their natural job of keeping the pest population down.  If I kill all the green stink bugs I see–especially one with a possible egg already on it–the flies will have less hosts for their young, so the green stink bugs then might become a problem because my breaking that cycle with my intervention could cause less flies in time to lay the eggs to keep the stink bug population down.

Trying to stay on the sidelines and decide whether to let nature take its course or if nature needs a leg up against the bug foes I have so I can have more food is a game of patient restraint.  Still, I’m doing my level best to be hands off when possible as I continue to develop our gardens into a sustainable ecosystem for exactly these sorts of natural balances.  In the long run, that will mean less work and expenditures (time, funds for pesticides–even natural, and sprayers) for a lazy gardener like me.

If you want to encourage feather-legged flies (especially if you grow squash/melons as they parasitize squash bugs, or have Japanese beetles which they also attack), they drink nectar and so far I’ve seen flowering umbelliferous plants such as carrot, dill, and other herbs, and composite flowers such as asters and rudbeckias and Queen’s Anne lace listed as favorites.

Care to share thoughts on this?