Stem borer (Diptera: Agromyzidae) in Sanicula

Some puparia of this stem borer show very short horns or possibly even no horns at all in the posterior spiracular areas, while at least one puparium I recovered from a stem in 2020 possessed strong posterior spiracular horns. Puparia with short or no horns seem to have the spiracular areas less darkly pigmented. I am unsure if this represents variation within a single agromyzid species or if more than one species might be involved, but I suspect two species. With regard to the host plant, there are at least four kinds of Sanicula in the geographic area covered by the current study, and I have not yet attempted to identify these plants beyond the genus level during the dormant season when puparia may be found in their dead stems. Thus, I do not know how many of these Sanicula species play host to an agromyzid borer.

Some of the information on this page is also included in Eiseman et al. (2026), where some of my reared adults were identified as M. subvirens.