140 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 



NORTHERN LIMITS. 



According to Professor Dawson, who has devoted much attention to 

 the study of the history, habits, and movements of the locusts in British 

 America, "northward they appear to be limited by the margin of tlie 

 coniferous forest which opportunely follows the line of tbe North 

 Saskatchewan Eiver." In the Northeast they have evidently passed 

 beyond this line, as they hav^e been seen at Swan Lake House and occa- 

 sionally at Cumberland House, showing that in this direction they 

 occasionally penetrate to the northern end of Lake Winnipeg. West- 

 ward from this point the limit line appears to bend southward, passing 

 between Prince Albert and Fort Garleton, following very nearly the 

 53d parallel by way of Battleford and Fort Pitt, running a little south 

 of Fort Edmonton, the Battle River Yalley being sometimes infested 

 by the locusts. From near Fort Edmonton the line curves around and 

 follows the eastern flanks of the Rocky Mountains down to Fort McLeod, 

 in longitude 113^ 40', latitude 49^ 35'. The northernmost limits, then, 

 extend to Fort Pitt, in latitude 53^ 40' (approximate), and the general 

 northern limits of the range of C. spretus extends nearly to the south- 

 ern limits of the forests which lie partly upon the 53d parallel, but, 

 in greater part, between longitude 104° and 114<^, above the pro- 

 jected route of the Canadian Pacific Railroad.^^ We know nothing of 

 the species of Caloptenus which probably inhabits the fertile area 

 between Athabasca and Peace Rivers. Mr. H. Scudder has a speci- 

 men of Caloptenus atlanis' from the Yukon River, and while it is proba- 

 ble that the boreal and subarctic region, north of latitude 53^, is inhab- 

 ited by Caloptenus atlanis and /(3m^^r-rw5r^*m, which thus range from the 

 Atlantic to the Pacific Oceans, it is probable that the long-winged 

 migratory spretus does not range beyond the line of coniferous trees 

 lying along the north shore of the north branch of the Saskatchewan 

 River. 



TVESTERN LIMITS. 



North of latitude 44° the westernmost point in which the Rocky- 

 Mountain locust is known to breed abundantly at certain seasons is in 

 the Missoula Valley, which lies on or near the 114th meridian. 



Between Missoula and Lewiston there are no locust breeding grounds, 

 so far as we know j «till, as locusts were known in 1875 and 1876 to 



2» Since tbe above was put in type we have received from the author Mr. G. M. Dawson's N tes on tbe 

 Locust in the Northwest in 187fi (Canadian Naturalist, vol. viii, No. 7), in which he states : " Tbe range 

 of the \ocust is really limited to the north by the soutbern margin of the forest-clad country, and may 

 be roughly defined by a line nearly as follows: From the intersection of tbe 9Gtb meridian and 49 h 

 parallel of latitude to tbe south end of Lake Winnepeg, thence to Manitoba Lake, and following this 

 lake and Winnipegosis Lake; from the north end of the latter westward to the Forks of the Saskatch- 

 ewan, till the woot:ed country at the baee of the Eocky Mountains is altained." He quotes Mr. S. D. 

 Mulkins, of Battleford, who "says: " From all the information I can collect, I cannot find that tbe grass- 

 hopper has ever visited any of the Hudson Bay Company's posts north of latitude 53°. I have never 

 heard that they have ever penetrated to the Peace River country. . . . At Fort a la Corne, Prince 

 Albert Mission, Turtle Lake, Lac la Biche, Lac la Nun, and Lac Ste. Anne, they have never been seen; 

 and these places are all on the verge of tbe great forest or just within its eoutheni limit." 



