ART. VIII.— ON THE DISTRIBUTION OF TINEINA IN COLORADO. 



By V. T. Chambers. 



Dr. Packard mentions, in Hayden's Report for 1873 (p. 518), that Lieu- 

 tenant Carpenter fonud a Tortrix larva somewhere in the mountains of 

 Colorado, at an altitude of above 12,000 feet, and this seems to have 

 been the only Microlepidopterou seen above timber-line by Lieutenant 

 Carpenter. I do not lind that any other species has been recorded from 

 high altitudes in the Kocky Mountains. At an elevation of nearly 

 11,000 feet, I saw a specimen of a Tortrix and two specimens of a 

 Pterophorus, but unfortunately was not able to capture either. This 

 was near the top of Mount Elbert. Aryresthia altissimella Cham, 

 was captured on the same mountain at an altitude of about 11,000 

 feet, and a specimen of A. gcedartellaf Auct. was taken at the same 

 place. Plutella cruciferaruni was taken, aud a specimen of a Coleophora 

 observed but not captured, at about the same elevation, near Ber- 

 thoud's Pass ; and Phyllocnistis popidiella Cham, was found in the lar- 

 val state up to the extreme limit of the growth of the aspen, 11,000 

 feet or more. Larva3 of two species of Gelechia were found as high 

 up, sewing together aspen-leaves; and the larva of another species 

 was found at a higher altitude than any other larva of Tineina, fairly 

 above timber-line as it is generally understood; that is, the limit of the 

 growth of pines; for it sews together the leaves of the stunted willows 

 which creep along the margins of little rivulets for a short distance 

 higher up the mountainside than the limit of the pines, up in fact to 

 a height of nearly 12,000 feet. But the distribution of the Tineina 

 is governed by that of the vegetation on which they feed. Of butter- 

 flies aud the larger moths, each species feeds usually on a variety of 

 plants, and their distribution is not determined by that of a siugle 

 plant. But the species of Tineina, and especially the leaf-mining Tineina, 

 are usually confined to a single food-plant. Comparatively few of them 

 feed on more than a single plant-species; and when a species does feed 

 on more than one species of plant, those on which it feeds are usually 

 closely allied. Of course, there are numerous exceptions, but this is 

 the rule, and when the rule prevails the geographical range of the moth 

 is generally determined by that of its food-plant, so that when the plant 

 is not found, of course the moth cannot be ; and where the plant is indig- 

 enous, there the moth will usually be found with it. To a much greater 

 extent, therefore, than in other Lepidoptera, the distribution of a species 



