The gall's range is computed from the range of all hosts that the gall occurs on. In some cases we have evidence that the gall does not occur across the full range of the hosts and we will remove these places from the range. For undescribed species we will show the expected range based on hosts plus where the galls have been observed.
Created Feb 4, 2026 1:47 PM UTC
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Last updated Feb 4, 2026 1:47 PM UTC
Biology and taxonomy of the Rhopalomyia Gall Midges (Diptera: Cecidomyiidae) of Artemisia tridentata Nuttall (Compositae) in Idaho
Robert G. Jones, Raymond J. Gagné, William F. Barr
(1983)
Only a gall remains of the type series in the USNM. Cockerell subsequently collected more adults which were described by Felt (1915b).
The gall is a spherical mass of long trichomes, about 15 mm in diameter. It consists of an aggregate of several capsules each of which encloses a larva. From the figure in Felt (1940), the gall appears to be either a node or bud gall.
In the original description (Cockerell, 1890), the host of R. alticola was given as "a composite... a Chrysopsis or Solidago." Cockerell (1909) subsequently recorded the host as "Artemisia canadensis [now considered a subspecies of Artemisia campestris]." Felt (1917) later listed "Artemisia forwoodii (? canadensis)" and, questionably, A. caudata as hosts. Baker (1895) reported a similar gall on "A. dracunculoides."
