Monthly Archives: February 2011

I don’t spend very much time looking at the exterior walls of the house, except for at one time of year: those first warm days of spring. Having noticed the small milkweed bugs gathered in the warm, sunny patches along the south wall of the house last Friday, I walked the length of the south and west sides looking for anything else that might have come out to enjoy the gorgeous afternoon.

Aside from a couple of small spiders and two lethargic flies, I didn’t find any other critters. I did, however, discover this. About an inch long, it was stuck very firmly to the concrete foundation on the west wall, not too far from the bird feeder Dan installed against the window. Leaning down to peer at it I could make a guess at what I thought it was, but after I peeled it from the wall and could look at it more closely I was certain. Can you guess?

It’s the paper shell of an ootheca, the egg case of a praying mantis. I’ve only ever seen these once before, nearly three years ago, back in Toronto. (It was in one of the earliest posts on this blog.) At that time I noted that they were generally found on the sunny south side of structures; this one was on the sunny west side. They superficially resemble cocoons at first glance, but they’re firm to the touch, whereas cocoons are generally springy. They’re also segmented, and this is visible even from the outside. The sides are ridged in narrow strips indicating the segments of the case. On the top the segments come together in a pattern that kind of resembles a zipper, creating a seam.

It’s hard to see that on this one, though, because it’s been torn apart. I suspect a chickadee, and not just because of the ootheca’s proximity to the bird feeders. Plastered a foot and a half up the wall as it was, it’s probably out of the reach of a small rodent (as well as ground-foraging birds like sparrows). I’m not sure whether a red squirrel could have reached it from the ground, either, but since it was on the concrete I at least know that the squirrel couldn’t have come across the wall to it (with our log house they have no trouble scampering up and down the exterior).

The only feeder birds that have feet strong enough to cling or hang from things are chickadees (goldfinches sometimes do too, but with much less frequency). I can just picture a chickadee clinging precariously from the ootheca, its tail fanned against the wall as it hammers on the hard shell of the case between its feet, digging out the protein-filled eggs inside. It also looks to be a pellet of dried bird poop sitting on the top of the case in the first photo, but I couldn’t rule out the possibility that this was from a feeder visitor and separate from the predation event.

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As an aside, I apologize for having fallen behind with comments; before the puppy came home I was busy trying to wrap up stuff to do with the moth guide so it’d be out of the way, and now that he’s here I spend most of the time that I’m not tailing after him just trying to be moderately productive. I really appreciate hearing from everyone, though! I’ll hopefully catch up soon.

I’m still working my way through the photos I collected last week. It’s a good thing I got so many blog topics backed up, because since bringing the puppy home I’ve barely had any time to go out and take some more. These were taken Friday, just before heading out to get the pup. Friday was gorgeous. Beautiful temperatures, clear skies, and even though it was rather windy, the air was warm, not nippy. I could’ve stayed out all afternoon, if I didn’t have places to be. Since I did, I just stuck around the house, but I turned up a few things there so I was still happy.

These Small Milkweed Bugs (Lygaeus kalmii) were all over the sunny parts of the foundation. The concrete had warmed up in the sun, and they’d gathered there to soak in the heat. There were quite a few also in the dead vegetation, so I’m not sure whether the bugs had been wintering in cracks in the house, or tucked beneath all the vegetation on the ground. Given that last spring I would find them crawling around the dead grass in the meadow, however, I’m inclined to believe the latter.

It’s funny that, growing up, I never noticed them around, while out here they seem quite common. We had milkweed there, too, but not nearly the amount of it that we have here (in fact, I’m not sure I’ve ever seen an area with quite so much milkweed as here), so I wonder if it’s simply a function of food plant abundance. Or, perhaps, I just wasn’t that observant as a kid.

They’re easily confused with the Box Elder Bug (Boisea trivittata), which is actually what I thought they were at first (which is funny – I did the same thing last year). Box Elder Bugs will overwinter in the nooks of your house and are often encountered in large groups at the first thaws in the spring, so it would make logical sense. Small Milkweed Bugs share the black and red aposematic (warning) coloration telling predators they don’t taste good (the result of the toxins in the milkweed seeds they feed on in the fall), but they have more red than the Box Elder Bugs. The pattern of the red creates a heart shape of the black on its back.

Of course, there’re not many milkweed seeds (their dietary item for which they’re named) to eat at this time of year. During the early spring, the bugs can get by scavenging dead vegetable matter and detritus or even preying on other insects. They switch to nectar once flowers start blooming, which carries them through the summer. When you’re most likely to notice them, though (assuming they don’t start crawling over your house foundations in the spring) is during the late summer and fall, once the milkweed pods develop. Then both they and their nymphs can be quite common on the plants.