756 EXPERIMENT STATION KECORD, 



Lime-sulphur washes for use on foliage, E. S. Salmon {Jour. Southeast. 

 Agr. Cut. Wye, 1910, No. 19, pp. 336-ii50). — Previously uoted from aiiotber 

 source (E. S. R., 23, p. 745). 



ECONOMIC ZOOLOGY— ENTOMOLOGY. 



A biological survey of Colorado, M. Gary ( (7. i^. Drpt. Ayr., Bur. Biol. Sur- 

 vey, North American Fauna No. SS, pp. 256, ?>/s. 12, fiys. 39). — This report con- 

 sists of 3 sections. The first characterizes the 5 life zones which traverse 



* the State, defines their extent and limits, and discusses their agricultural and 

 economic possibilities. The second consists of a complete list of the mammals of 



• Colorado, with brief notes on their habits, distribution, and economic relations. 

 The third is a list of the principal trees and shrubs of Colorado observed by 

 the assistants of the Biological Survey during the progress of the work in the 

 State with annotations as to their distribution aud abundance. 



A colored map of the life zones of Colorado and a complete index of the sub- 

 ject matter are included. 



The mammals of Bitterroot Valley, Mont., in their relation to spotted 

 fever, H. W. Henshaw aud C. Birdseye {U. S. Dept. Agr., Bur. Biol. Survey 

 Cira. 82, pp. 24, figs. 12). — This is a report of investigations carried on from 

 March 12 to July 14, 1910, and continued in 1011 in cooperation with the Bureau 

 of Entomology and the IMontana Station. It also embodies numerous data ob- 

 tained by assistants of the Biological Survey in previous years. The investi- 

 gations were undertaken for the primary purpose of ascertaining the particular 

 species of wild mammals in and near the valley which harbor ticks, esi>ecially 

 Dermacentor venustus, the species chiefly responsible for the spread of Rocky 

 Mountain spotted fever. 



" The almost complete restriction of the fever to the western side of the 

 valley has occasioned much speculation and given rise to a theory of its possible 

 connection with some native mammal or mammals living solely on that side; 

 but a study of the rauge of the mammals of Bitterroot Valley has failed to 

 show that a single species is restricted to the western side. Nevertheless the 

 two sides differ physically so widely as to influence greatly the distribution of 

 mammals. On the west side the mountains rise abruptly, forests or brush 

 covering much of the land except the cultivated tracts ; while on the east side 

 a strip of rolling, treeless, sage-covered bench land lies between the river and 

 the mountains. Thus the west side has a somewhat more humid climate than 

 the east, with heavier growth of brush, which furnishes good cover for most of 

 the small mammals, aud hence favors the presence of ticks. But on the opposite 

 or less humid side good ' tick country ' occurs only around those ranches which 

 nestle close up to the mountains. Ground squirrels, chipmunks, woodchucks, 

 and pine squirrels — animals which were found to be the principal hosts of the 

 nymphs and seeds of the fever tick (D. venustus) — are mainly absent from the 

 broad strip of sage-covered bench laud." 



In the course of the investigations more than .500 mammals were collected in 

 and around the valley and 20 species were found to carry ticks either in the im- 

 mature or adult stage. " The hosts of fever ticks fall naturally into 2 groups, 

 those that harbor chiefly adult ticks and those that harbor the younger stages. 

 In the former class belong mountain goats, bears, coyotes, badgers, woodchucks, 

 and possibly elk, deer, mountain sheep, rabbits, and domestic stock, as horses, 

 cattle, and sheep. Those of the second class, mainly rodents, comprise ground 

 squirrels, woodchucks. chipmunks, pine squirrels, mice, and wood rats." 



Experiments are now being made in the Bitterroot Valley to discover the 

 most practical methods of destroying the several species of mammals that act 



