The adults of the Chaoborus sp. Midge are fairly nondescript, and look like mosquitoes with out the needle like blood sucking mouth parts.
The larvae however are quite remarkable organisms. Their body, with the exception of their eyes and the 2 pairs of air sacs, is completely transparent, to the extent that their last meal can be seen in their digestive tract. This has given rise to the common names glass worm and phantom or ghost midge larvae.
They grow to approximately 1cm long and can be found in ponds and lakes, where when they can sometime be found in large numbers by simply sweeping a fine mesh net through open water.
They are predators and hunt by hanging motionless and horizontally in the water column, using their air sacs to help with buoyancy, and wait for their water flea or copepod prey to come within reach of their unique prehensile antennae, which have fused into one grabbing pincer like appendage, which catches their prey and bring it towards their teeth like mandibles.
They can swim by wriggling their whole body, a movement aided the line of stiff hairs at the end of the body on the base of the last segment of the abdomen.
The species adapted to survive in fish filled lakes and ponds they will hide in the bottom sediment, with some species in living at depths up to 70m to avoid these fish predators.
Once the larvae fully grow, they metamorphose into a pupa. This pupa is not immobile as in some types of insect, but can swim using paddles at the tip of the abdomen. and hangs at the surface using two snorkel on top of the head to breathe.
Once the adult emerges it does not feed on blood like the mosquitoes it resemble and those that do eat feed on nectar. Once mated the females lay eggs on the water surface in a jelly disc, within which are 100 eggs arranged in a spiral. In many species the they over winter as larvae and winter and early spring from my experience seem to be the best time to find them in small ponds with areas of open water