62 
Psyche 
[June 
With the aim of providing some definite information on 
the foodplants of Lepidoptera I have begun collecting and 
preserving specimens of the plants, to be submitted to 
authoritative plant taxonomists for precise determinations. 
I propose to publish annotated lists of these foodplants from 
time to time. In the present contribution I have been sub- 
stantially aided in obtaining plant identifications by my 
colleague, Dr. John R. Reeder, Curator of the Herbaria at 
Yale University, and I owe thanks to him and to the de- 
terminers : Dr. Reed C. Rollins, Director of the Gray 
Herbarium at Harvard University; Dr. S. F. Blake, Senior 
Botanist of the U. S. Division of Plant Exploration and 
Introductions; and Mr. Carleton R. Ball, of Washington, 
D. C. Specimens of most of the plants are being preserved 
for future reference in the Herbarium of Yale University. 
The initials of the determiner follow each species in 
brackets. The present paper is devoted to foodplants of 
Lepidoptera occurring in the state of Colorado. Unfor- 
tunately, in the following list little can yet be said about 
the suitability of the plants as permanent food. Notes on 
field observations are included. Records of the parasites 
obtained will be held for future publication. 
Papilionidae 
1. Papilio eurymedon Lucas. On 15 July 1949, J. D. 
Eff saw a female oviposit on a leaf of Crataegus rivularis 
Nutt. [R.C.R.] on the western slope of Rabbit Ears Pass, 
in Routt Co., Colo. The larva eclosed on 29 July and was 
preserved. In California Comstock recorded the foodplant 
as Rhamnus calif ornica. My correspondent there, W. H. 
Evans, wrote (in litt.) : “A Papilio eurymedon laid four 
eggs on cultivated jasmine. Each year this species oviposits 
occasionally on this plant but I have never seen larvae on 
this vine. This year I gave them tender leaves on which 
they nibbled for several days, eating just barely enough 
to keep alive; then I gave them some of the native food 
plant, Rhamnus crocea ilicifolia. But all died without even 
tasting these leaves.” 
2. Parnassius smintheus Dbldy. & Hew. A single ovum 
was found 6 July 1949 attached to a leaf of Oxytropis 
