Neolasioptera ambrosiae

N. ambrosiae is hard to find because there is usually no apparent gall or only the slightest swelling; occasionally, it causes a noticeable fusiform swelling on the small side branchlets. One to several larvae occur in a stem where they crawl up and down silken tubes where the pith would normally be. Before pupation, the larva cuts a hole almost all the way through the twig and retracts into the pith, where it overwinters. In spring the larva pupates, and the adult emerges a short time later.

- Raymond J. Gagne: (1975) The gall midges of ragweed, Ambrosia, with descriptions of two new species (Diptera: Cecidomyiidae)^©

Reference: https://www.biodiversitylibrary.org/page/16310692#page/68/mode/1up