Thursday, October 24, 2013

An early trip to a small stream in Sugar Hollow

My friend and I went to a small stream in Sugar Hollow this morning where I was hoping to find some freeliving caddisfly larvae and more Perlodid stones -- but it's still a little too early.  We did see some small Chloroperlids, lots of small flatheaded mayflies, and a good number of common stoneflies: they all looked to be Acroneuria abnormis, but I didn't keep any to check.   But the insect of the day was the Giant stonefly, Pteronarcys proteus.   The leafpacks were loaded with them.  And while most were on the small side, we did find some -- like the one in the picture above -- that clearly will be hatching by the end of the winter.   This one was a beauty!

Note one of the key feature for species ID -- the lateral projections on abdominal segment 7 are closer in shape/size to those on segment 6 than to those on segment 8.


2. Malirekus hastatus.  I wasn't completely shutout in my search for Perlodids: I did find this Malirekus hastatus (you'll recall that I found one on 10/8 as well).

These are great streams for Perlodids, and we'll be seeing more and more species as we move through the winter and spring.

3. Baetis tricaudatus.  This one surprised me: the small minnow mayfly Baetis tricaudatus.  I've come to think of this as a species that we start to see in the winter -- my thinking is in need of revision!

A very handsome male (large, red eyes).  Note the diagnostic features of the pale, medial line on the abdominal terga and the very short middle tail (caudal filament).

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