Cecidomyiidae

Rhopalomyia

Erigeron foliosus

California

Oregon

Erigeron serpentinus

Key to American Insect Galls

Rhopalomyia erigerontis

Rhopalomyia erigerontis new species

Hosts: Erigeron fragilis [foliosus]

This is an oval apical bud deformation with a length of 10 mm. and a diameter of 7 mm., the modified leaflets being thickly clothed with a short white pubescence.

Range: CA

New Western Gall Midges

Rhopalomyia erigerontis

Host: Erigeron fragilis [foliosus]

Oval apical bud gall, length 10 mm, diameter 7 mm.

R. erigerontis is known only from the specimen reared in April, 1913, from a gall on a plant provisionally identified as Erigeron fragilis.

The gall midges of California Diptera: Itonididae (Cecidomyiidae)

Rhopalomyia erigerontis

Hosts: Erigeron "fragilis"

Apical bud gall

Galls are whitish-downy

Range: CA

The plant-feeding gall midges of North America

A similar gall was observed on Erigeron serpentinus in California in [May](https://www.inaturalist.org/observations/79019668). This gall is tentatively assigned to this inducer based on the similarity of the galls but may not be induced by the same midge species.