How to Manage Pests

Pests in Gardens and Landscapes

Baccharis gall fly—Rhopalomyia californica

Baccharis gall fly adults are tiny, delicate flies that lay tiny reddish eggs on terminals. Orange maggots are up to 0.063 inch long in galls.


The baccharis gall mite causes fleshy, knoblike swellings or galls on shoot tips. Galled shoots stop growing.


Plants are not killed by baccharis gall flies. Tolerate galling on plants. Many species of beneficial parasites attack gall fly larvae; conserve natural enemies. There are no known artificial controls.

Galling of shoot tip
Galling of shoot tip

Statewide IPM Program, Agriculture and Natural Resources, University of California
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