Green Lacewings (alive)

2010 September 4

Way back in April of 2007, I had pictures of a dead Green Lacewing that we found in an old spider web. These pictures had some serious deficiencies: (1) I hadn’t learned how to steady the camera or get good magnification yet, and (2) The lacewing was long dead, dried up, and had probably had its juices sucked out by the spider that owned the web we found it in. So, let’s try this again. Here’s one we found on August 1, fluttering around a porch light during the night:

The body is about half an inch long (10-12 mm). The wings are large, fragile, and practically noiseless as the lacewing flies, and when it rests they get folded over its back kind of like a roof.

They have lovely eyes, with kind of a smouldering orange effect surrounded by green that I now kind of wish I’d photographed at higher magnification (the head is only about a millimeter across).

Oh, hey, I see another one hanging out on the wall in the hall. Hang on a minute while I get the camera and put on the high-magnification lens.

[ . . . Flighty little thing, aren’t you – hold still (click, click), no, no, don’t fly off (click, click), not in my hair, back on the table please, all right, that’s better, look at the camera (click, click), whoops, there she goes . . .]

OK, here we are: Lacewing eyes!

The two lacewings are not quite identical, this second one has black and red marks on the face while the first one had a uniformly green head. I don’t know if that signifies anything, but it probably means that these two specimens are not the same species (and maybe not even the same genus).

These are rather attractive, harmless insects in the family Chrysopidae, which are collectively called “green lacewings” even though not all of them are green. The adults evidently mostly eat honeydew off of aphids (and in some cases, eat some of the aphids as well), but as Alex Wild shows here, the larvae really seriously devour aphids and other small insects. In fact, they are so effective for eating aphids, whiteflies, and similar pests that lacewing eggs and larvae are commonly sold for pest control. Because of this, I am not entirely certain that the lacewings that I find locally are really native to the area: they could easily have gotten established after somebody bought and released some for pest control in their garden. Then again, their native range goes all the way up into Canada in any case, so who knows.

Lacewings are in the relatively small order[1] Neuroptera, which also includes other families with aggressively predatory larvae, like antlions. Lacewing larvae are broadly similar to ant lions, with the same kind of huge mandibles that they use to grab prey and suck out their juices. The main difference is that antlion larvae wait for their prey to come to them, while lacewing larvae go out hunting for them.

Lacewing eggs are interesting, too: they are laid attached to plants, and are on stalks so that the egg proper sticks way up above the surface. This is evidently an adaptation to protect them from ants. See, the lacewing eggs tend to be laid in areas where there are likely to be a lot of aphids. But, many aphids use honeydew to seduce ants into hanging around to lick them, and at the same time the ants go around eating things that might prey on the aphids. If an ant finds a lacewing egg just resting on the plant stem, it will eat it. But, if the egg is on a stalk that holds it up above the ant’s head, then the ant is much less likely to stumble upon it and eat it.

I gather that, even though they look fragile, the lacewing adults are actually the form that overwinters. That way, the adults can go out in the spring and lay their eggs near likely prey aggregations, rather than laying them at random and hoping for the best.

And, incidentally, this appears to be a good year locally for lacewings – I see at least a couple pretty much every time I walk out back, and they all look pretty green and healthy. Interestingly, I’m not seeing many of the Asian Multicolored Lady Beetles that used to be so very, very plentiful in past years. I wonder if some disease knocked out the invasive lady beetles, and opened up the aphid-eating niche for the lacewings to exploit? Or, maybe the lacewing larvae have developed a taste for the larvae of the asian lady beetles?

[1] There are still about 300 species of Neuroptera, which for reference is about equal to the total number of species of birds that have ever been seen in the wild in Michigan, but this is small compared to the number of, say, beetle species in North America (about 23,000)

6 Responses
  1. Bob W permalink
    September 4, 2010

    The eye picture: Lacewing.Facing.jpg just begs to be a full size screen background.

    Definitely a cool shot. I wonder if the orange eyes indicate sensitivity in the (closer to) the UV side of the spectrum

  2. Carole permalink
    September 4, 2010

    Wonderful post.
    I’ve been missing lady beetles here in north Florida this year also. I’ve only seen two, both the invasive Asian multicolored.

  3. September 4, 2010

    No lady beetles here in southeastern Wisconsin yet, but my memory is that they show up in mid-autumn around here.

    Apparently the monarchs have arrived, though; the word at a block party today is that they’re hanging from the trees in the local habitat just waiting for the weather to warm and the wind to die down before continuing onward.

  4. September 5, 2010

    Unfortunately for turning the lacewing eye picture into a screen background, that’s the highest resolution image I’ve got. Their heads are pretty tiny. But yes, something along those lines would be amusing.

    As far as the lady beetles, since our season is so short here, right around the beginning of September is when we usually see them trying to get into buildings. The cluster flies, who usually come in around the same time, are turning up as expected, but not the lady beetles. More as things develop.

    And as for the monarchs, I’ve always lived pretty much at the extreme northern part of their range, and didn’t realize that even in Wisconsin their migration swarms were large enough to be noticeable. At any rate, we had a lot of monarchs in the UP this year, so you should be seeing a lot of them from us.

  5. September 8, 2010

    Fantastic! Even though this is the highest resolution, it’s a great shot. Thanks for the post, looking forward to more.

  6. September 11, 2010

    That face shot was indeed wondrous.

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