"Pupal color can be pale yellow to light brown to dark brown. They are 2 to 5 mm in length with an unsegmented cephalothorax that has a pair of respiratory horns that may bear spines or wrinkles." http://creatures.ifas.ufl.edu/aquatic/biting_midges.htm

"Pupae of aquatic species hang in the surface film by their respiratory horns."

"The pupae are difficult to separate from those of some other families but all have the following characteristics: the well developed respiratory organs are each a single, undivided structure (not bifurcating), the third leg is curled under the wing sheath, with only the tip protruding, the apex of the abdomen is more or less straight (not curled under the thorax) and has two pointed anal processes (never a paddle), the pupae is not enclosed in a silk tube (at most a poorly developed silk tube in which the abdomen is loosely encased), and the pupae are not very active: the most they can do is to move their abdomens in slow circular motions." http://www.inbio.ac.cr/papers/Ceratopogonidae/whatmakes.htm

It sounds like the description fits this one pretty good, and the size is just within the large end of the scale.

I am not sure which. Finding info on these is tough!
-Sean McCann


triatoma.blogspot.com

The key in Aquatic Insects of North America(1) says Chaoboridae has (1) two wide paddles at the tail end with a distinct midrib, (2) respiratory horns swollen at the middle. This picture shows neither feature.

Dixidae has "2 long pointed caudal lobes that are immovable, narrow, and fused basally."

Ceratopogonidae and Chironomidae have "paddles absent or if present not fused basally", matching this picture (present, separated instead of fused). The illustration of the former family is a better match. I can not find a key that goes beyond family for Ceratopogonidae.

link to picture of larva and pupa of Ceratopogonidae

Well that's more than I knew before. I was amazed at how many really tiny things were swimming in the water I took out of the swamp. I didn't even want to try photographing them, less than 1mm.