It is time for the midges to come out of hiding and fly up your nose. Or better yet, in front of your camera lens. Here are some photo requests to ID beyond tribe (the usual level of ID). This is mainly about Chironomini, which are the most frequently noticed midges. It should serve more or less for the family.
In addition to wing veins and general appearance, Chironominae require extreme closeups of the male genitalia for identification.
Most of these are 3:1 to 5:1 magnification on captive specimens, mostly of Chironomini but one each of Pseudochironomini, Tanytarsini, and Orthocladinae. The pictures are generally close enough to at least tentatively ID to subgenus or species. I use reversed lenses; some of you will use an MPE-65.
Most Chironomini have two pairs of appendages between the large claspers, the superior and inferior volsellae (singular: volsella). In these pictures, and in most genera, the inferior (aka lower) is longer. Sometimes one pair is greatly reduced.
Some of the characters illustrated (not in order):
there is usually a long hair at the end of the inferior volsella, sometimes better seen from below. In Dicrotendipes
the inferior volsellae are strongly curved upwards and have an enlarged tip. In Einfeldia
and Chironomus (Lobochironomus)
the base of the superior volsella is swollen. In Chironomus
both pairs of appendages are fairly simple and the lower nearly straight. In Paratendipes
both can be small.
A major division in the Chironomini is between the species with 13-segmented flagellum (e.g. Polypedilum
) and the species with 11-segmented flagellum (Chironomus
group and "Harnischia
complex"). Getting this character is helpful.
Classification also relies on details of tibial spurs and spines and shape of pronotum. So far I have never found useful information in photos of tips of tibiae, but maybe some day. (I did eventually make sense of a 3:1 macro of the front tibia of a fungus gnat.)
Pronotum is visible in these shots. Note that because the head is angled down you have to be more forward than you think to get the critical top view showing the notch in front.
Some groups are more difficult than others. These views of Ablabesmyia
(left) and Procladius
(right), in subfamily Tanypodinae, are not close enough. ID requires more magnification on a slide mounted specimen. They are good enough for genus.