Since it would be impossible to show all 5,000+ species of aquatic Diptera here, given are three examples of diverse, common midges. These examples share traits that are common in all aquatic Diptera. The three families choose span a large range in size and shape, from the very small Simuliidae (black fly) to the large Tipulidae (crane fly). The most common of all aquatic midges is the Chironomidae having 175+ genera and 1000+ species.
When a fishermen uses the word, midge, they are usually referring to any very small aquatic or terrestrial insect. On the other hand, when entomologists refer to a midge, they are speaking of Diptera, the order of true flies. Diptera means 2 wings, and encompasses all common flies, such as a housefly. This is one of the larger orders of insects; there are over 16,000+ species with 5,000 + having aquatic larval stages (that’s a lot of Latin). Luckily their diminutive size and their common characteristics make them easy to imitate
What midges lack in size, they make up for in quantity. Think of it this way – the largest mammal on this planet; whales, feed on the smallest organism; plankton.
Why? Because plankton are readily available, reproduce quickly and are numerous in quantity (high biomass). The lower you are on the food chain, the smaller your size, the faster you reproduce, the larger your quantity. Midges might not seem to be a big meal for a trout, but their availability and high quantities make them a food source that we can not overlook.
Midges go through complete metamorphosis, giving the fisherman three chances to imitate them: the larva, pupa, and adult stages. Because some midges have fast reproduction and are multi-brooding, these three stages are available to trout year round. You can find midges on warm days in the dead of winter on most trout waters.
Midges have gotten a bad rap over the years. Commonly called the fisherman’s curse, their small size has made them difficult to fish. Today’s technology, small hooks and light tippet, makes it easy and productive to fish the midge.
A Midge larva has all of the following characteristics
- No segmented legs
- Prolegs usually on abdomen and thorax
- Maggot or worm like body
- Head that may retract into body
Midge adults have the following characteristics
- 2 wings that lie flat over the body at rest
- No tails
- Short antennae no longer than the length of the body