March 26, 2017 Trip Report
Apr 2, 2017
ME, Readfield
Kennebec County
Beaver Brook
38 ◦F Air Temp
One of the nice things about collecting aquatic insects is that you can collect in the middle of winter. You can also collect terrestrial insects if you know where to look, but aquatic insects are easy – they are in the water. Even though we have a pretty decent layer of snow on the ground the air temperature was warm and we chose to explore a little creek near us – Beaver Brook.
As I said, the temperature was warm – warm enough so that the
winter stoneflies were hatching. This one I believe is in
family Capniidae – at least I caught a 
similar one the week
before and keyed it out to that family.
We’ve been doing a lot of our collecting recently with a small
seine we made out of old tent poles and window screen. We
then place what we find in a small lidded storage container (like a
Tupperware) where we painted the bottom white, so we can see the
contrast of the insects. We
also pick up
stones and pick off critters that catch our attention.
In this particular creek the numbers were a little thin, but we
found some good specimens.
There were plenty blackfly larvae – all these specks 
on my hand in this picture are
blackfly larvae that came off a rock that I was holding. Yep,
we’ll be losing some weight via blood loss when these guys all
hatch this spring…
We found three nice fishfly larvae – subfamily
Chauliodinae. They look a lot like hellgrammites, but
don’t have the gills under each abdominal filament. These guys are
active predators and had hefty jaws that would grab the forceps
when I was picking them up.
In terms of mayflies – we found a nice example of someone in
family Paraleptophebia. These are “crawler” type mayflies –
and are 
identifiable by
their cylindrical body shape, and in these guys, their nice long
antennae. The real give away, however, are their forked gills
– indeed these are known as the fork gilled mayflies.
In this family in particular, they have long filamentous extensions
on the gills that you can 
see in this
picture.
Altho not an insect, we did catch a few planarians.
Planarians are flatworms – they glide along a surface and they have
a tube like mouth at the bottom of their body which they
use to collect
food. Interestingly their digestive system is pretty
primitive – they only have one opening so they eat and poop out of
the same hole (yet one more reason to be happy you are not a
flatworm). The food is distributed throughout their body by
branches of their digestive system that reaches all the
corners. This can be seen easily in this picture as the
dark pattern on the planarian. Planaria are also famous for
their powers of regeneration. You can cut a planarian
in half and the two halves will regenerate forming two new
planarian. Nice, but not nice enough to make up for the fact
that you have to poop and eat out of the same hole. On some
of these pictures you can also see the “eyespots” that are light
sensitive organs.
It was a nice trip – short, nothing earth shattering, but a wonderful way to get out in the off season and poke around in a stream.