9 
pest this cireular has been prepared. ‘The account of the habits and 
seasonal history of the insect, list of food plants, and description of 
both larva and adult represent the work of the many observers men- 
tioned in the paragraph on history and distribution, as do also the clos- 
ing statements as to natural checks upon its increase, and preventive 
treatment. 
HISTORY AND DISTRIBUTION. 
The first observation on this insect was made by Mr. Albert 
Koebele.t an agent of this office, who found the larve burrowing in 
grass stems in California in 1890, and who reared the adults. From 
these and others which had been collected in Montana and Nevada the 
species was described by Riley and Marlatt, who said: * The eco- 
nomic importance of this species arises from the fact that it may be 
expected at any time to abandon its natural food plant in favor of 
the small grains, on which it can doubtless successfully develop. 
Such changes in the food habits of our native insects are constantly 
oceurring to the great detriment of our agriculture, as is illustrated 
by the attack of the’ Vematus and Dolerus species on wheat, these 
insects normally affecting wild grasses.” 
The fulfillment of this prophetic suggestion was not long delayed. 
In 1896 the late Dr. James Fletcher,’ entomologist to the Dominion 
of Canada, reported that he had found the adults, which he be- 
heved were those of Cephus pygmaeus 1, the European species, at 
Indian Head, Northwest Territories [Saskatchewan], and that Mr. 
John Wenman, of Souris, Manitoba, had sent in wheat straws con- 
taining larve. Mr. Wenman wrote that the damage resulting from 
this attack was not appreciable. In 1902 Doctor Fletcher * found 
the larve numerous in grasses in the Northwest. In 1905, 1906, and 
1907 the junior author observed the work of the larve in grasses 
throughout the northwestern United States, and in 1906 found them 
damaging wheat at Kulm, N. Dak. In his report for the year 1908 
Doctor Fletcher again referred to this insect, stating that in the pre- 
vious autumn it had appeared in central Manitoba and the south- 
eastern part of Saskatchewan in much more serious numbers than at 
any previous time. * The broken straws which resulted from its attacks 
were seen in many fields and occasioned some alarm.” Mr. Norman 
Criddle*—a farmer and careful observer of insects, of Aweme, 
Manitoba, and the inventor of the grasshopper poison which bears 
his name—recognized the insect as Cephus occidentalis, and wrote 
Doctor Fletcher at the end of the season that the species had increased 
@Tnsect Life, Vol. III, p. 71, 1890. 
b Ann. Rep. Exp. Farms Canada f. 1896, pp. 229-230, 1897. 
¢ Letter. 
@ Ann. Rep. Exp. Farms Canada f. 1907-8, pp. 191-192, 1909. 
Cire] 
