Pine Sawflies from 2012 Library Bug Hunt
As part of our presentation on local insects at the public library on August 23, 2012, we had a “Bug Hunt” in the small park area behind the library. One of the things we did was to put a bedsheet under a pine tree in the middle of the lawn, and then wack the branches with a stick to see what would fall out. Mostly, what we got were these:
Each of the pictures here is a different individual. While the first one had a somewhat gray head, this next one (which is flipped over so we can see its chubby little prolegs) has a fully-black head.
And this next one shows why there is some variation in head color: it is molting, with the skin just peeling back from its head and front end. And its freshly-molted head is practically white (as are its six true legs). So that first one had probably just finished molting no more than a couple of hours previously.
Both the head and front legs will turn dark again over time, looking like this one again:
For more details about pine sawflies, please see my previous post about them. The main thing to keep in mind is that even though their larvae look like some kind of moth caterpillar, they are actually going to grow up looking more like stout-bodied wasps (which they are related to). And that you can tell sawfly larvae from moth caterpillars by counting the prolegs (sawfly larvae have more than 5 pairs of prolegs, while caterpillars have 5 pairs or less).
 Well, it’s finally happened – I’ve lapped completely around the calendar, and am now posting pictures taken one year previously. So for the next few weeks at least, I’ll be posting bugs that you may actually find if you go out looking for them the same day as the post goes up. And, actually, all of the postings for the last month or so also went up at the same time of year as their subjects are likely to be running around.
 It probably isn’t that surprising that we got one that was in the middle of molting, because while molting they aren’t as able to hang onto the tree as they would be normally. So, when a bunch of kids start whacking the tree branches with sticks, the larvae that are in the middle of a molt are way more likely to lose their grip and get knocked off of the tree.