Wing Venation

Wing venation plays a vital role in Diptera identification -- you can identify the insect just by looking at the veins.

Four Major Veins

The veins can be hard to locate. Figure 1 shows the base part of the wing. The four major veins (costa, radius, media, and cubitus) are shown in the photo. Those four veins are common in the wings of Diptera, or rather, in all winged insects.

Figure 1. Wing Venation, Four Major Veins

Suborders of Diptera

The branching patterns of those veins tell you what insect you are looking at. Anal veins, for example, tell you that the insect in the photo is one of suborder Nematocera (nematocera = long horned) since the anal cell is "open", which means second anal vein does not merge into cubitus.

Figure 2. Wing Venation

Figure 3 shows the suborders of the order Diptera.

Figure 3. Diptera Classification

Chironomidae Family

Next, look at the un-branched radial sector and media. These are characteristics of the Chironomidae family (Figure 4).

Figure 4. Wing Venation

The antenna of Chironomidae males is plumose (Figure 5). The many-segmented antennae are another feature of Nematocera species.

In suborder Brachycera (brachycera = short horned) the antennae are three or four segmented and stylate (with styles). In Cyclorrhapha (circular-seamed), the antennae are three-segmented and aristate (with arista).

Figure 5.Antenna

Mouse Part

Unlike Culicidae (Mosquitoes) family species, the mouse part of Chironomidae lacks a proboscis. Shown in Figure 6. are maxillary palps.

Figure 6. Mouth Part

Thorax

The thorax of the insect is curved (Figure 7).

Figure 7. Thorax

Conclusion

Figure 8 shows the insect -- a midge.

Figure 8. Midge (Family: Chironomidae),

This individual was found resting still on a branch on a late fall morning . Midges hibernate, usually under leaves and branches. The shiny red aquatic midge larvae are good fishing baits. They live in mud tubes, and swim with sporadic stretch of their body.

October 24,2001
Portland, OR