August 11th, 2010


Urban wildlife mystery maybe

This was one of maybe a dozen winged insects, of different sizes and apparent stages of development, adhered to a rock in Babbling Brook (the stream that leaves Ward's Pond and becomes the Muddy River). I thought maybe they were very slowly emerging imagos (adult insects) and pupae. I sent this picture to an insect id community and mostly they were stumped too. The best explanation I got was that these were female caddisflies which had died shortly after laying eggs in the water. The white growth (someone supposed) was a fungus consuming the dead insects' bodies. It seems plausible to me.

I tried to figure out if this was a normal part of the caddisfly life cycle, but I couldn't tell. Interestingly, there's a lot of information about caddisflies online from the perspective of people who make pretend insects with which to catch fish. They had some good things to say, but I didn't get my questions answered. The log cabin caddsfly entry I did for the 365 project (click above link) included pictures of caddisfly larvae collected a short distance downstream from the mystery insects.

Anyone else have any bright ideas?

Urban Nature Pictures 8/9; 50 More Urban Species #27: Hairy Rove Beetle

Hairy rove beetle Creophilus maxillosus

This rove beetle was found roving around a fly trap. This kind of fly trap is a simple jar filled with water and a nasty smelling lure, with a lid that has small holes in it. Flies (mostly carrion flies, but some houseflies and others) fly into the trap, fall into the water and die there, contributing to the attractiveness of the aroma. The stink attracted this beetle as well, and well it should have since this species specializes on eating flies and maggots on filth and carrion.

Unlike other rove beetles I've observed, this individual unfolded its wings and flew around a bit. I was skeptical back when I first encountered the devil's coach horse that there were functional wings underneath the tiny wing covers on the beetle's back. Not having an abdomen covered with a hard elytra (like other more familiar beetles such as ladybird beetles do), rove beetles are free to waggle their hind ends alarmingly, in the manner of an earwig. Instead of pincers, the hairy rove beetle has a gland which produces a chemical defense. The active ingredient, dihydronepetalactone, is being studied as a possible repellent against mosquitoes and stable flies.

Visiting Boston

I posted these pictures on Facebook and wasn't going to bother putting them here, since their "nature" quotient is very low. But I've been posting a lot of arguably gross bug pictures, and not everyone who reads this is a bug person. So a friend of Alexis' from high school (who lives far away now) was in Boston for business, and we met her and went out for dinner and drinks.

I hadn't spent any time in the Back Bay lately, and I was impressed with its beauty. My photos are actually a pretty poor representation, but they hint at the wondrous scale and contrast of the architecture. It took me years to appreciate Boston (or any, really) architecture, but now I think I get it.

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