Local feeder (Diptera: Cecidomyiidae) in petioles of Acer

This tentative record refers to a possible cecidomyiid affecting petioles of silver maple. In the only example I observed, a ~40-mm length of petiole tissue was externally blackened and slightly sunken (with no visible swelling); under the epidermis was an elongate tunnel, appearing as if divided into two tunnels positioned end-to-end. The proximal / lower end of the tunnel contained a slightly enlarged chamber with a small amount of whitish fungal growth, while the distal end, also slightly enlarged, contained a thin-walled whitish object, which I believed to be the remnants of a cecidomyiid cocoon. Though larvae were not present when I observed the petiole in late October, the size, length, and color of the tunnel, the whitish cocoon-like object, and the blackening and sunkenness of the petiole exterior were all consistent with Neolasioptera sign I encountered on stems and stemlike structures of other plants during the course of the survey. I examined approximately 200 additional petioles of fallen leaves from the same tree without locating a second example of this local feeder. Further investigation would be required to confirm that a cecidomyiid is responsible for the plant damage observed.