Cone Feeding Midges, (Cecidomyiidae) (7, 20, 24, 27)

Several species of midges (small flies) in the family Cecidomyiidae (Diptera) have been identified as cone pests.

BIOLOGY. - Very little information is available on the biology of cone feeding midges attacking the southern pines. Both conelets and cones are attacked, but damage seems to be more common on
cones. The larvae feed in groups on both the seed and cone tissues.

INSECT IDENTIFICATION. - The larvae are 2 to 3 mm long, tapered, and variable in color from near-white to orange. Adults are very small and mosquito-like, with long delicate legs and antennae (2 mm long). Several insect genera have been identified, but the relative importance of the individual species is uncertain.

Pine cone scales removed to expose cone feeding midge larvae and pupae. (2X)

DAMAGE IDENTIFICATION. - Cone feeding midge larvae feed between the cone scales and cause resinosis and withering of the scales. Internally, infested cones have areas of dead resin-soaked tissue between the scales, which are notably free of any boring frass. Externally, cone feeding midge attack is indicated by brown sunken areas on the cone surface, often accompanied by some resinosis. This damage often causes distortion and a decrease in size of cones.

Loblolly pine cone damage by cone feeding midges. (1X)

IMPORTANCE. - Accurate estimates of the impact of cone feeding midges on cone production are not available. Casual observations, however, indicate that the incidence of damage is usually low.