61 



In 1902, and in far greater numbers in 1903, the insects appeared on 

 the south slope of Badger Mountain. This land has been settled only 

 within the last five years. The outbreak during 1903 was so serious 

 that the count} 7 authorities appropriated funds to combat the insect, 

 which in its march reached within a few miles of Waterville, the 

 oldest wheat-growing region in the county, and where the insect was 

 never before known. It was found much cheaper to stop the insect 

 by fences made of 1 by 12 smooth boards placed on edge than by 

 ditches, and after these were built the progress of the insect was 

 stopped, but not before several thousand acres of wheat were 

 destroyed. Those of the insects not destroyed oviposited in the soil 

 near the barrier fence. No evidence whatever was seen of any return 

 migration to other breeding grounds. 



It is evident that the control of this locustid offers no difficult prob- 

 lem, and it is possible practically to exterminate it by no other means 

 than fencing or ditching. 



Attempts were made in 1902 and again in 1903 to inoculate it with 

 the South African Mucor, but all the attempts proved fruitless. If a 

 disease could be found, the chances of its spreading are particularly 

 favorable, owing both to the insects' habit of congregating in great 

 numbers at night in the shelter of plants and low bushes and from 

 the further fact that they are cannibalistic. 



The distribution of this insect is remarkable. It was described by 

 Thomas from specimens collected in 1872 in the mountains of south- 

 western Montana at an altitude of 9,000 feet. No other collections 

 have been made since except these recent ones in Douglas County. 

 In "Washington it seems to be nor mall} 7 an Upper Sonoran insect, only 

 occasionally invading the transition zone. The Montana types are 

 from the boreal zone, and as they are well preserved there can be no 

 question as to the identity of the Douglas County insect, which 

 matches the types exactly. 



Scudder's monotypic genus Peranabrus is founded on Thomas's 

 Tliamnotrizon scabricollis and differs from Anabrus only in its rough- 

 ened pronotum. 



In answer to a question asked by Mr. Felt as to whether this spe- 

 cies devasted the country as they marched along, Mr. Piper replied 

 that they fed upon the grass, and were also carnivorous to some 

 extent. 



Mr. Fletcher asked if it were not possible that these large crickets 

 were largely carnivorous; he had eviscerated a large number of 

 Anabrus purpurascens when preserving them, and had never found 

 any vegetable matter in their stomachs. He also remarked that the 

 latter species was abundant in Manitoba. 



