Gall Midge
Cecidomyiidae
Gall Midge, Gall Gnat
Rhopalomyia solidaginis adult
by Beatriz Moisset. CC BY-SA 4.0
Cecidomyiidae is an insect family comprising the gall-forming midges. Gall-forming refers to the tumour-like growths that plants produce in response to larval-feeding within the host plant.
Some groups in the family are of economic significance, namely because they use cereal and vegetable crops as the primary food plant.
On the other hand, there are several species in the family which are predaceous and natural enemies to other pests, such as aphids, whitefly and scale insects. Some species are even produced commercially and sold to greenhouse growers as biological control. The rest, feed primarily on fungi and detritus; or some can be parasitic.
Traits

Some possess predaceous larvae that eat pest insects.

Some gall midges are important agricultural pests which attack cereal and vegetable crops.
Appearance
Adults: They're small (0.5- 3.0mm) and described as 'mosquito-like'. They possess one pair of wings; the other pair are modified and look like tiny, club-shaped appendages, poking out between the insects' thorax and abdomen. These are specialised body organs used to improve balance while in flight. The wings are also hairy, which is unusual for True Flies (order: Diptera). The antennae are long with tiny delicate hairs. The antennae are what's known as Moniliform; meaning they appear like a string of beads. The head is small and cone-shaped, and the legs long like stilts.
Larvae: The larvae look like small yellow, red or orange; sometimes they can be creamy-green as they grow larger. They lack heads and legs. They are often associated with abnormal bumps and lumps on the plant, which is a result of their feeding behaviour.
Activity
Diurnal
Personality
Order
Diptera
Family
Cecidomyiidae
Metamorphosis
Complete
Distribution
Worldwide