Friday, May 20, 2011
Getting Ready to Leave the Nest: Mature Insects Everywhere You Look
Not a benthic macroinvertebrate! This big snapping turtle was lazily crossing the road as I made my way back from Sugar Hollow this morning. He didn't seem to mind my taking this picture -- but I decided not to get any closer!
With almost all of our streams still running muddy and high, I headed back to Sugar Hollow today to see what I could find in another small stream that flows into the Moormons. This stream is almost directly across the valley from the one I visited yesterday. But it's smaller, and if anything it drops even more steeply downhill.
"Mature" is the word for the day. Lots of nymphs with black wing pads, including this Ameletid mayfly.
This is a treat. You may recall that I saw quite a few Ameletids in a number of streams -- all small streams -- in February and March. I've seen very few since, and I thought they had all hatched. So it was really nice to see this one. All insects mature and hatch later in these high mountain, 1st level streams. As fly fishermen know -- "the hatch moves upstream". The insects of a particular family or genus will hatch first in the lower parts of a river or stream, and the hatch progresses upstream as the weather warms and the colder waters upstream along with it.
Another insect I'm finding less often downstream -- the Epeorus flatheaded mayfly. Again, I found a mature one up here.
Beautiful, light coloration. Not sure if that's a matter of habitat and location or having just molted to a new instar.
Finally -- a nice mature Perlodid stonefly: Isoperla, what else?! This does not seem to be any of the three species I found yesterday -- judging by the head pattern.
(Sorry for the quality of this particular photo. We had low light conditions at the time.) The Isoperla picture below, on the other hand, does match up with one of the species we saw yesterday.
I need to send my Isoperla shots from yesterday and today to the folks at Bugguide.net to see if they can help me out with species ID.
The final picture I'm posting today is a Freeliving caddisfly larva. It's a very unusual color, kind of an aqua blue or green. As I've noted in previous entries, "color" cannot be used as a key trait for family identification when it comes to this caddis family.
VACATION. Please note that I'll be in Italy all of next week. So please look for a new post around the 1st of June.