188 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 90 



River. Because of the large size of these individual plants they have, 

 for many years, been considered conspecific with the true Leptotaenia 

 multifida of the high plateau of the Palouse region around Pullman, 

 Wash. 



Suspecting some error in my rearing records of this and allied 

 species, or in the identification of the hosts, I supplied larvae feeding 

 on true Leptotaenia with food from the Snake River locality. They 

 refused this substitute food. Wlien this evidence was obtained further 

 investigations were carried out which proved, beyond doubt, that the 

 food plant is Lomatium grayi. 



A long series of moths has been reared from larvae collected in 

 several localities. These moths show some variation in structure and 

 habits, but not enough, I think, to warrant separation. Superficially 

 the moths cannot be distinguished, nor can the larvae or pupae. 



The differences in habits are directly the result of the variations 

 in the host plants themselves. As already pointed out, the plants 

 growing in the sandy or gravelly bars of the river are unusually large, 

 while those growing on the dry banks a few yards away are scarcely 

 recognizable as the same species. This plant grows also in the Blue 

 Mountains of Washington and Oregon up to altitudes of slightly over 

 6,000 feet. As might be expected it varies greatly in its different 

 habitats there, from a small, sessile plant to one almost reaching the 

 proportions of the individuals of the Snake River bars. 



The moth, however, apparently does not go above 5,700 feet, 

 although it is common at that altitude at Godman Springs, in the 

 Blue Mountains. 



The larvae collected at Godman Springs show some colorational 

 differences but I think these unimportant specifically; one often finds 

 such differences in larvae from one locality. The larvae from God- 

 man Springs measured 12-14 mm. in length, 2 to 3 mm. smaller than 

 the mature larvae from the Snake River. This difference, I believe, 

 is purely the result of the different environments. 



The larval habits of the mountain insects are much the same as 

 those of the desert-inhabiting individuals. The former differ, how- 

 ever, in producing much more webbing of the parts of the plants 

 affected, with pupation frequently taking place in the webbed leaf 

 sheaths. I failed to find a pupa (living or dead) in the stalks of the 

 mountain plants although I did find a few larvae in the flower stalks. 

 All of the larvae found in the stalks were parasitized. Because of 

 the small number of larvae and pupae found I suspect that many 

 larvae pupate in debris at the base of the plant. A brief description 

 of the pupa is as follows : Wing, antennal and leg sheaths bright green 

 gradually becoming darker and duller, tinged with brown. Abdomi- 



