62 GRASSHOPPERS AND OTHER INJURIOUS INSECTS OF 1911 AND 1912. 



THE LARCH SAW FLY. 



This, like the Clover-seed Chalcis, is now an Adams Fund 

 project, and consequently is best discussed in detail, in an Experi- 

 ment Station publication. 



Mr. Ruggles, to whom this project was assigned, lepoited upon 

 the work of 1909 and 1910 in the Thirteenth Report from this office, 

 page 109. The work has been pushed as fast as possible during the 

 past two years, and touching briefly on the results it may be said, 

 (1) Only 1 per cent of the specimens reared from a large number of 

 cocoons were males. (2) Young larvae were observed the last of 

 August, 1912, making- it appear possible that there is a second gen- 

 eration, though no pupae were seen. (3) In the Insectary larvae 

 fed impartially on American Larch (Tamarack), European Larch 

 and Western Larch. (4) Many young larvae in the Cloquet district 

 were killed in the fall by some agency, possibly an early frost. 

 (5) Large black ants (specimens not obtained by observer) were 

 found to destroy larvae. (6) Koochiching County, in northern part 

 of state, bordering upon the Canadian line, appears to be the worst 

 infested area. 



THE CAMPAIGN AGAINST THE HOUSE FLY. 



The campaign against the house fly in Minnesota, begun in 1909, 

 has been actively pushed during 1911 and 1912. Some of the city 

 dailies, notably the Minneapolis Tribune, have printed frequently 

 "Swat the Fly" articles, pointing out the danger accompanying the 

 toleration of flies about the house and containing common sense 

 directions for lessening the evil. 



In July, 1911, this office published an illustrated circular of in- 

 formation, entitled, "New Methods of Combating the House Fly." 

 The chief purpose of this circular was to emphasize the fact that the 

 female house fly, in its adult stage, lives from eight to fou7'teen days 

 before it hegins to lay eggs, and that if co-operative effort in a 

 neighborhood was made to trap flies during that period, beginning 

 early in the season, the tremendous increase of the pest resulting 

 from continuous and unchecked breeding during the summer could 

 be reduced to a minimum. In other words, the public were urged 



