[last-instar larvae:] spatula long, lateral pairs of dorsal abdominal tubercles weakly bifid

C. piniinopis and C. resinicola are the two most widely distributed species of Cecidomyia. Both occur on many species of hard pine (Diploxylon) in eastern North America and in the West. I have seen specimens of C. piniinopis from P. banksiana (Mich., Ontario, Wis.), P. contorta (Brit. Col., Yukon Ter.), P. elliotlii (Fla.). P. ponderosa (Ariz., Brit. Col., Calif., Idaho, Oreg., Wash.), P. rigida (Maine, Md., N.Y., N.C.), P. strobus (Md.), P. virginiana (D.C., Md., Va.), and P. sp. (Ark.). Larvae of C. piniinopis usually occur singly in small pitch droplets and sometimes in inconspicuous pockets at the base of needles.

Cecidomyia piniinopis

Hosts
Ponderosa pine; occasionally lodgepole pine.

Distribution
Throughout host range.

Damage
Attacks occur near branch tips in early summer. New shoots fade, droop, turn yellow, and die. Repeated attacks which do not kill the shoots may twist and stunt branches. Beneath the bark, small resinous pockets are formed by developing larvae. Trees 4-16 feet in height are most heavily infested. Small trees may be killed.

Identification
Needles on infested shoots die in tufts which soon droop and turn yellow. Later they become red-brown (fig. 86). These flags are scattered over part or all of the crown and appear by summer. Extensive twig killing, stunted or distorted growth, and sparse, off-colored foliage are symptoms of persistent heavy infestations. Infested shoots will have slight swellings on their surface which enclose bright orange to red maggots about one-eighth of an inch long (fig. 87) from July to the following June. The resin infiltrates the wood around pits and sometimes exudes over the twig. Larvae overwinter in pits under bark. Adults emerge in early spring after larvae migrate to surface of branch to pupate.

Similar damages
Damage is similar to Diplodia blight. Pitchy "gouts' on twigs and larvae, when present, distinguish this pest.

Larvae may be single to gregarious. They pupate in a white cocoon some distance away from the resin mass in which they feed...
Larva in inconspicuous pits at base of needle fascicles, usually on hard, or two- and three-needle pines...
C. brevispatula Gagne...
C. piniinopis Osten Sacken
...
This species has been found on white pine as well as on many hard pines. It and C. resinicola have the greatest host distribution of the genus. Hosts: P. banksiana, P. contorta, P. elliottii, P. ponderosa, P. rigida, P. strobus, P. taeda, P. virginiana...probably wherever pines grow.