40 CIRCULAR 8 4 9, U. S. DEPT. OF AGRICULTURE 



Leucania phragmatidicola Guenee 



(Figs. 4, Y; 7, Q) 



Distribution. — This species occurs throughout the United States 

 east of the Rocky Mountains and in California. 



Economic status. — It is of no economic importance in the central 

 Great Plains. 



Food plants. — The larvae feed on various grasses including blue- 

 grass and wild-rye, and are most commonly found in grassy alfalfa 

 fields, in pasture lands, and along grassy roadsides. 



Seasonal history. — There are two generations annually. These 

 armyworms overwinter as partly grown larvae, and are full-grown by 

 the last of March. They pupate in April and May, and the adults 

 appear late in May and early in June. No larvae were taken during 

 the summer, but adults again appeared in numbers in September. 

 In some years light-trap collections showed the adults to be present 

 from late in April to the middle of October, with two periods of 

 pronounced abundance, one early in June and the other early in 

 September. 



Natural enemies. — Of 40 larvae collected in the field, only 1 

 developed disease; none were parasitized. 



Cirphis unipuncta (Haworth) 



Army worm 

 (Figs. 4, X; 7, P) 



Distribution. — The army worm is found throughout the United 

 States east of the Rocky Mountains and in Canada. It is also 

 recorded from Utah, California, and northern Mexico. 



History and economic status. — This species is of major economic 

 importance, being one of the most destructive of the Phalaenidae. 

 The larvae periodically appear in hordes and, assuming the army 

 habit, do widespread damage to crops, particularly the cereals. 

 The armyworm has been known to be a serious pest of cereal and 

 forage crops since early colonial times. In 1632 Peter Kahn, a 

 Swedish naturalist traveling in this country, recorded it as injuring 

 corn 6 in New England. In 1743 there was a great outbreak in what 

 is now the North Atlantic States. There have been other outbreaks 

 at irregular intervals, one of the most severe on record being in 1861. 

 In 1914 the entire region east of the Rocky Mountains was injured. 

 Extensive outbreaks were also noted in 1937, 1938, and 1939. 



Food plants and larval habits. — The armyworm prefers grasses, but 

 feeds on a wide variety of plants. When the larvae assume the army 

 habit, they feed during the day, although normally they remain 

 hidden at that time. The larvae frequently feed on the heads of 

 ripening wheat, gnawing into the spikelets containing the forming 

 seed, eating the awns, and often severing the head at its junction 

 with the stem. In one instance a field of Kanred wheat, a bearded 

 variety, had been injured so severely that from a distance it appeared 

 to be a beardless variety. Of 1,000 straws examined, none of the 



6 In colonial times wheat was referred to as corn, and the term "maize" was 

 applied to corn. 



