June, ’18] 
SEVERIN’. NATIVE HOST OF RHAGOLETIS FAUSTA 
325 
A NATIVE FOOD PLANT OF RHAGOLETIS FAUSTA O. S . 1 
By Henry H. P. Severin, Ph. D., California Agricultural Experiment Station 
Although the northern or black-bodied cherry fruit fly ( Rhagoletis 
fausta 0. S.) was described by Osten Sacken (12, p. 346) in 1877, the 
fact that this trypetid is a serious pest of cultivated cherries was not 
definitely determined until 1910. As to the native food plants of 
Rhagoletis fausta, Illingworth (11, p. 195) writes as follows: 
“From the occurrence of the type material in the alpine regions of 
the White Mountains the inference would be that the native foods were 
wild fruits, the most natural food plants being some of the species of 
wild cherries or plums, or possibly the berries of some of the species of 
Berheris or Lonicera. 11 
Caesar and Spencer (5, p. 7), who have worked with this fruit fly in 
Ontario, state: “No injury was found on any of our native wild varie¬ 
ties of cherry, but only on the imported ones or on those that had 
grown up wild from the seeds or roots of these.” 
In regard to the host plants of the European fruit fly ( Rhagoletis 
cerasi) Hagen (9, p. 160) writes- “Loew states that the larva lives in 
cherries, in Lonicera xylosteum and other Loniceroe, and in Berheris 
vulgaris, after Frauenfeld. Rosenhauer found it in Lonicera tartarica, 
and this shrub was also present in my garden for thirteen years,” 
but as far as I know, is not infested by a trypetid. 
An examination of the wild red, bird, fire or pin cherry ( Prunus 
pennsylvanica L.) in Orono, Maine, near the Penobscot River, showed 
that most of the fruit had been punctured by insects. A few hours 
observation disclosed the fact that a curculio was puncturing and gnaw¬ 
ing holes in the wild cherries to such a depth that the snout was entirely 
embedded in the flesh. Some of the wild cherries were opened and 
occasionally a Lepidopterous larva was found, but we did not succeed 
in breeding the moth. Most of the fruit when opened, however, 
showed a brown streak in the flesh extending from the skin to the stone. 
On July 23, 1914, when the wild cherries were ripe, about a quart 
of the fruit was gathered from trees and scattered in sterilized sand 
within jars. During the month of August numerous yellowish pu- 
paria were sieved from the sand and were kept in moist, sterilized sand 
over winter. Under laboratory conditions the adults of Rhagoletis 
fausta issued during the following spring. 
In the season of 1915, from July 25 to August 6, ripe wild cherries 
1 Permission has been granted by Dr. C. D. Woods, Director of the Maine Agri¬ 
cultural Experiment Station, for the publication of this paper. 
