Antistrophus spp.
Rosinweed cryptic leaf gall wasps

Hosts: Compass plant (S. laciniatum) and prairie dock (S. terebinthinaceum)

Gall location and description: Species belonging to this group induce galls in the petioles and occasionally larger veins of the leaves. Thus far, galls seem to only be induced in the basal leaves, but it is possible that galls are also induced in leaves on the main stem. As with several other herb gall wasps, galls of species in this group are cryptic and leave no discernable trace on the surface of the leaf. When dissected, the leaf will reveal numerous brown, oval-shaped chambers along the inside of the pith, each with a single insect.

Range: Galls of this species group have only been found in Iowa, Ohio, and Wisconsin thus far, but they can probably be found throughout the native ranges of the host plants.

The rosinweed cryptic leaf gall wasps appear to be related to those inducing cryptic galls in rosinweed stems, but their exact relation is unknown. Whether galls on the two hosts comprise one or two species also remains to be seen. These galls were just recently discovered, and more research is necessary to understand their biology and locate possible additional host plants.

- Louis Nastasi, Charles Davis: (2022) Field Guide to the Herb and Bramble Gall Wasps of North America^©