Local feeder (Diptera: Cecidomyiidae) in stems of Ageratina

In September, I located a single polythalamous stem gall of this local feeder near the tip of an upper stem. The gall featured 2 exit holes and 8 individual chambers lined with whitish fungus, with the exit holes each opening from one of the chambers. At least 2 of the chambers -- apparently the same ones with exit holes leading to the outside world -- had insect exoskeleton remains in them, but most of the other chambers appeared to be empty, and these empty chambers also did not have obvious holes leading to the outside of the gall. Any insects that had successfully developed in the gall had already emerged, and this fact and all other characteristics of the gall closely match the description of Asphondylia eupatorii in Gagné (1989). Compare with the Neolasioptera galls on this host (record 0022).

See also: Ageratina stem insects compilation