Cecidomyiidae

Chamaediplosis

Callitropsis nootkatensis

Alaska

California

Oregon

Washington

British Columbia

Hesperocyparis pygmaea

Bionomics and life history of the gall midge Chamaediplosis nootkatensis Gagne & Duncan (Diptera: Cecidomyiidae) on yellow cypress in British Columbia

Chamaediplosis nootkatensis

Contarinia sp.

Larva in swollen branchlet tip
Branchlet tips are swollen

Host: Chamaecyparis nootkatensis
Distr: British Columbia and Washington

The plant-feeding gall midges of North America

Small, readily recognizable galls (Fig. 2f) are apparent by the time early second-instars are present. Galls are globose and similar in color to the foliage. Typically, the basal portion of two to four pairs and occasionally up to six pairs of scale leaves are modified as a result of gall development. 

Tip-Gall Midge
Chamaediplosis nootkatensis

This gall induces slight swelling of the branchlet tips of Nootka cypress and pygmy cypress and possibly other cypress species. These monothalamous galls develop in spring and are light beige-yellow when fresh.

Plant Galls of the Western United States

The [2021 Gagne & Jaschhof catalog](https://www.gallformers.org/source/287) lists only "Cupressus nootkatensis" as a host, but Russo 2021 says gall also occurs on pymgy cypress and possibly other cypresses. 

Most iNaturalist observations of "Chamaediplosis nootkatensis," however, are on Monterey cypress (Cupressus macrocarpa).