36 



even if they should recur for years, as they are uot likely to do, could 

 not be entirely overcome. The county commissioners of the two coun- 

 ties affected were consulted. They understand the situation, and with 

 the aid of the admirable law on the subject, it is supposed that sys- 

 tematic warfare will be waged this fall and the locusts exterminated. 



THE NATIVE SPECIES. 



Associated with spretus in this region there was an unusually large 

 number of M. atlanis (principally the large, very dark-colored form 

 mentioned by Scudder in his Meianopli, p. 18 >, from the Northwest Ter- 

 ritories) which the preceding dry seasons had caused to flourish. In 

 many places this form, which seems certainly worthy of nominal recog- 

 nition, has caused as much damage as spretus in others. M. bivittatus 

 was seen everywhere in a most flourishing condition, and was by all odds 

 the most common locust observed. By the 20th of August the females 

 of this species were depositing eggs, often for this purpose boring 

 down in the hard beaten roadbed, where millious were destroyed by 

 the passing vehicles. The edges of grain fields and land under sum- 

 mer-fallow that was measurably firm from rains or otherwise were 

 generally selected. At one place about 10 miles northwest of Bot- 

 tineau and near the Dominion line, .1/. pacMrdi was as numerous as 

 the other species were anywhere, and demonstrated that it should be 

 listed among the locusts capable of the greatest destruction. This 

 species prefers the roadsides for the deposition of eggs. As it evinces 

 an inclination to abandon wild grasses and to feed upon cultivated 

 grains it should be watched, for the rather disastrous results that have 

 followed a similar change of food habit by Dissosteira longipennis 

 might be repeated. It seems, however, that a peculiar succession of 

 favorable seasons has brought about results that may not become fixed 

 nor in any way normal, and that may net occur again for many years. 



In general it may be stated that the parasites have not been suffi- 

 ciently numerous in the Turtle Mountain region to affect the situation 

 at all. Trombidiiun locustarum was often seen and was generally dis- 

 tributed. As a test, near Dunseith I captured 25 individuals of spretus, 

 and of these 18 had mites upon them. But in a slightly removed 

 locality only 2 or 3 out of the same number were found parasitized. 

 Some parasitic Diptera were seen, but the number was not large. All 

 in all, the locusts were remarkably healthy. 



SUMMARY. 



I. Melanoplns spretus does not breed permanently in the Turtle Mountains nor in 

 that immediate vicinity. The ground is totally unsuited to the purpose, and, more- 

 over, swarms descending upon North Dakota and Minnesota have been traced from 

 far to the northwest of that place. The probable permanent breeding ground is 

 upon the Assiniboine River, north and east of Regina in the Territory of Assiuiboia. 



II. There has been a visitation of Melanoplus spretus in North Dakota, besides at 

 New Rockford, near Rolla. The county authorities will probably take the matter in 

 hand and reduce the danger to a minimum. 



