Rhopalomyia tumidibulla
Blister Gall Midge

This midge induces small, integral, lenticular, monothalamous galls in leaves of Great Basin sagebrush.

Adults emerged in the laboratory on March 25-26 from galls that had been collected March 18, 1970. In the previous year's rearing, they emerged on April 24-25 from galls collected April 22, 1969.

This monothalamous gall, when mature, consists of a swelling that is apparent on both surfaces of a persistent leaf (Fig. 15). A sclerenchymatous larval capsule is located centrally within the leaf swelling. Two mature galls measured 3 mm. in depth, 3 mm across the leaf width and 4 mm along the leaf length.

Gall protruding from both sides of leaf...Rhopalomyia tumidibulla Gagné

Galls are about 3 mm in diameter and appear on persistent leaves...Host: A. tridentata