Janetiella coloradensis Felt (Diptera: Cecidomyiidae) causes severe needle shortening on pinyon, Pinus edulis Engelm. Infested needles are about one-third normal length, with swollen bases and enlarged fascicle sheaths.
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A purse-like chamber of needle tissue, separate from the enlarged needle base, developed around each midge larva. These chambers could be easily removed from the galled needles. A single chamber always contained a single larva (fig. 3). Shortly after the larvae entered the needle base the needles ceased to elongate...

Cembrotia coloradensis (Felt 1912), new combination, causes a needle-shortening gall on Pinus edulis Engelm. (Pinaceae) in Colorado (Gillet and Brewer 1983) and California (Russo 2006).

Janetiella coloradensis, new species.

Gall. — Length 4 to 5 mm., diameter 3 mm. This is a more or less regular, oval swelling at the base of the needles, containing near the center, a smooth, oval cell some 3 mm. long.

Pine-needle-gall midge

Cembrotia coloradensis

This midge induces needle galls on Colorado pinyon. Galled needles grow only about one-third their normal length. Gall color varies from green to purple-red and yellow.

Each larva in separate chamber, no more than one at base of each needle...
...Larva encased in removable capsule... Janetiella coloradensis Felt
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Ten or more larvae may enter the fascicle bundle, but usually one two, occasionally one or three, survive at the base of each needle bundle. Affected needles grow only to about one-third normal length, the base of the needle is enlarged, almost spherical, and the sheath enlarges to encase the gall and does not dehisce. A detachable capsule made up of needle tissue simulating two dwarfed needles surrounds each larva...
The species has been reported from P. virginiana... but the gall on that pine is formed by Thecodiplosis brachynteroides. Host: P. edulis...