ZOOLOGY 109 



mountains. It is one of the most common valley forms and 

 does more damage in alfalfa than any other. 



M. femur-rubrum. Also common here and occasional in 

 the Mts. It has not been collected from the mesa. It would 

 seem to be a little more mesophytic in its requirements than 

 the last species. 



Orphulella pelidua, Burn, 



Mermiria bivetattus. Occurs on Aster spinosus which covers 

 low sand dunes in the valley. It is entremely long and narrow, 

 which in connection with its color renders it as inconspicuous 

 on its leafless foodplant as the walking-stick (to which it has 

 a general resemblance) on Dalea. 



Helochara communis, Fab Common here and occurs up 

 into the pinion and Yellow Pine Assns. On Chrysothamnus 

 pucheyrimus in the Sandia Mts. at Santa Pe and Taos and on 

 Eudbeckia and Solidago in Jemez Mts. 



Culex pipiens. Mosquitoes breed in countless millions in 

 the ponds that form in the valley whenever the Rio Grande 

 is high. This usually occurs in May and June and some 

 when the snows are melting in the Colorado mountains and 

 sometimes in late summer at the close of the rainy season. 



There has been a good deal of discussion over the very 

 practical question as to how far mosquitoes will fly. This is 

 a very favorable place in which to study this problem as 

 there are no places away from the Valley where mosquitoes 

 can possibly breed. There is absolutely no possibility of 

 their breeding on the mesa. There are almost no inhabitants 

 there and no cisterns at all. There is no chance of their 

 breeding in tin cans. Although the mesa is the common 

 dumping-ground of the latter, in this dry atmosphere a can 

 even if it were full would lose all of its water through evapora- 

 tion long before a week was up. So we are perfectly safe in 

 saying that all mosquitoes seen on the Mesa have come from 

 the valley. In our worst places the writer has found them 

 quite numerous about half of the distance across the mesa, 

 tive miles from any possible breeding place. An acre of 

 ground here would perhaps shelter about one percent of the 

 number that an acre next to the river would. Beyond this 

 there were a few only. As to the wind as a factor; this was 

 carefully noted during one of our worst plagues. There is 



