December, '21] king and barber: army worm control 487 



During the Spring of 1914, the army-worm was very nimierous; 

 observed first about May 13th, by the 20th to 23d they began migrating 

 from the wheat into the com fields, the principal migration occurring 

 at about 2:00 p. m. of the 21st and between 4:00 and 5:00 p. m. of the 

 23d. So large was the number of lar\'ae issuing from the wheat that 

 they produced a distinct rustle as they moved among the leaves. By 

 May 29th the larA'ae were entering the soil to joupate and were becoming 

 scarce. 



Predator\' enemies and parasites were, in 1914, so num.erous as to 

 probably destroy from fifty to sixty percent of the larv^ae. 



The bob-o-link {Dolichonyx oryzivonis) occurs in such large numbers 

 about the wheat fields where the army-worms are plentiful that the 

 farmers call the species the "Army-worm bird" and believe, evidently 

 with some justification, that their presence always indicates the advent 

 of army-worms. 



Calosoma beetles, C. scrutator, C. liiguhre, and C. caliduni become 

 very numerous indeed during the seasons of great abundance of the 

 army-worm in this region, and were particularly nimierous during May 

 of 1914, although by the latter part of June they were scarce and by 

 July were difficult to find. 



Toads occur in considerable abundance and undoubtedly destroy 

 large nvmibers of the larv^ae, particularly where they congregate in the 

 furrows. 



Parasitic flies were, during 1914, very numerous: the principal 

 species being Winthemia 4-pustulata and Frontina aleiiae. Hymen- 

 optera apparently were less abundant although Apanteles militaris 

 was quite generally present and was reared in some ntmibers from the 

 larvae. 



Of the various schemes investigated in 1914 to protect the young 

 com fields from the swarming larvae, the two-furrow plan without post 

 holes appeared most successful on heav^- soil. In this system two furrows 

 are plowed along the edge of the com field adjoining the wheat, or from 

 the direction that the larvae are expected to enter the field. These 

 furrows are about three feet apart and are first made with a one-horse 

 plow, followed with a heavy three-horse plow to throw the earth up to- 

 wards the side of the com field, above the level of the ground. The 

 last plow is followed with a log 3' x 8" diameter to break up clods in 

 the bottom of the furrow. A second log (PI. 6, fig. 1) about 16" 

 in diameter and about two feet long is then drawn through the furrow 

 to smooth the bottom and lower half of the sides of the furrow. Finally 



barrel (PI. 6, fig. 2) dragged through the furrow smooths the sides 



