CUTWORMS, ARMYWORMS, AND RELATED SPECIES 39 



Food plants and larval habits. — Although this species is a general 

 feeder, it shows a preference for garden crops. The writer has taken 

 the larvae on sweetclover. The larvae are diurnal, but do not conceal 

 themselves as do most species of cutworms. 



Seasonal history. — According to Chittenden (2, pp. 30-37) there 

 are two generations annually. They pass the winter in the pupal 

 stage. The first-generation moths appear in May and June, the 

 second-generation moths late in August. At light traps adults were 

 taken from early in April to early in October. 



Natural enemies. — Of 10 larvae taken on sweetclover, 1 was para- 

 sitized by Apanteles militaris (Walsh), 1 developed the fungus 

 Metarrhizium anisopliae (Metsch), and 1 died of an undetermined 

 wilt. 



Protoleucania albilinea (Hiibner) 



Wheat Head Armyworm 

 (Figs. 4, 0; 5, B; 7, J) 



Distribution. — -This armyworm is widely distributed in Canada from 

 Nova Scotia to Alberta, and in the United States from the Atlantic 

 Coast States westward to Utah and Arizona. It is also found in 

 South America. 



Economic status.— -In the central Great Plains the wheat head 

 armyworm is of minor economic importance. In its eastern range it 

 causes widespread damage at times. 



Food plants and larval habits. — The species feeds almost exclusively 

 on members of the grass family, being most destructive to wheat, 

 oats, rye, and timothy. The larvae are diurnal, and their habit of 

 feeding on the heads of wheat has given the species its common name. 



Seasonal history. — Webster (22) states that there are two genera- 

 tions a year in Iowa. There the moths emerge in the spring and 

 deposit the eggs, which hatch the last part of May. The larvae of 

 the first generation become full-grown about July 1 and enter the soil 

 to pupate, the adults appearing in August to produce the second 

 generation. The larvae of the second generation mature late in the 

 fall, pupate, and remain in the pupal stage through the winter. 



In Kansas the larvae are most abundant in June. Adults were 

 taken at lights from late in March to the middle of October, with 

 two definite periods of heavy flight, one during the last 10 days of 

 April and the other beginning late in August and continuing well into 

 September. 



Reproductive capacity. — One dissected female contained 1,057 eggs. 



Natural enemies. — Of 156 larvae collected in the field, largely by 

 net sweeping in ripening wheat, 5 percent were parasitized by Hyme- 

 noptera and 1 percent by Diptera and 7 percent developed disease. 

 Parasites and the disease organism reared were as follows : 



Hymenoptera — Campoletis oxylus (Cress.), Rogas atricornis Cress. 



Diptera — Phorocera claripennis (Macq.). 



Disease organism — Metarrhizium anisopliae (Metsch). 



