
Keys to Midges
| Midge |
Black Fly |
Crane Fly |
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 feeds on the smallest organism; whales eat 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. With today's technology, though, small hooks and light tippet are readily available, and make it easy and productive to fish the midge.
Identifying Midges
A Midge Larva has all of the following characteristics:
1) NO segmented legs
2) Prolegs usually on abdomen and thorax.
3) Maggot or worm like body.
4) Head that may retract into body
Midge adults have the following characteristics:
1) 2 wings that lie flat over the body at rest.
2) no tails.
3) Short antennae no longer than the length of the body.
Types Of Midges
Since it would be impossible for me to show all 5,000+ species of aquatic Diptera on this page, I have given three examples of diverse, common midges. These examples share traits that are common in all aquatic Diptera. I have picked three families that 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.
Chironomidae
(Midges)
ILLUSTRATIONS BY: ANDY COOPER
Identifying Characteristics of Chironomidae :
- Larva
- Size range 1/16 - 3/4 of an inch.
- Long slender worm like body.
- Distinct head.
- Has a pair of prothoracic prolegs and a pair of terminal prolegs.
- Terminal segment has short tufts of hairs.
- Pupa
- Most species live within cocoons attached to rocks or vegetation (some are free swimming).
- Spiracular gills on top of head.
- Defined wing pads.
- Adult
- Two wings.
- Antennae are generally longer than the head and have hairs.
- Wings are delta shaped.
Simuliidae
(Black Fly)
ILLUSTRATIONS BY: ANDY COOPER
Identifying Characteristics of Simuliidae :
- Larva
- Size range 1/8 - 5/16 of an inch .
- Swollen abdomen.
- Fanlike mouth brushes.
- Larva are attached by the end of their abdomens to the top of rocks.
- Pupa
- High branched spiracular gills on head.
- Pupa can be found in slipper-shaped cases on rocks and vegetation.
- Adult
- Wings are broad.
- Thorax has strong arch.
- Antennae are short.
Tipulidae
(Crane Fly)
ILLUSTRATIONS BY: ANDY COOPER
Identifying Characteristics of Tipulidae :
- Larva
- Size range 3/8 - 1 inches.
- Some have retractable heads.
- Body has peglike appearance.
- Pupa
- Aquatic pupa are rare.
- Straight legs that extend beyond developing wings.
- Aquatic pupa will have respiratory horns.
- Adult
- Large mosquito like flies.
- Very long legs.
Table of Common Diptera
Chironomidae
|
Common Midge
|
Blephariceridae
|
Netwinged Midges
|
Ceratopogonidae
|
Biting Midges
|
Fly patterns for Midges.
| Metamorphosis |
Life Stages of Insects |
Keys to Larvae |
Keys to Pupae |
Keys to Nymphs |
|
Keys to Adults |
Keys to Stoneflies |
Keys to Caddisflies |
Keys to Mayflies |
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