CUTWORMS, ARMYWORMS, AND RELATED SPECIES 



41 



heads had escaped injury, over half had been partially destroyed, and 

 the rest had been severed from the stems. 



Seasonal history. — There are normally three generations of this 

 species annually in the central Great Plains. The army worms pass 

 the winter as partly grown larvae or in the pupal stage. In mild 

 winters the hibernating larvae probably carry the species through the 

 winter. Adults begin to emerge early in the spring and are present 

 in varying numbers from early in March to late in November. The 

 larvae are most abundant during May and June, but at times are 

 numerous in September, especially in millet. The summer generation 

 has never been observed in important numbers. The eggs are laid in 

 the leaf sheaths of various grasses, where, upon hatching, the larvae 

 feed, moving only in search of food. The adults are strong flyers. 



Natural enemies. — Generally the larvae of this species are heavily 

 parasitized, particularly those of the spring generation. Larvae 

 were collected from 1922 to 1940. From those reared the mortality 

 from various natural enemies was determined, with results sum- 

 marized in table 5. 



Table 5. — Mortalities oj larvae oj Cirphis unipuncta caused by various 

 natural enemies, 1922-40 





Larvae 

 observed 



Larvae killed by — 



Total 



mortality 



Year 



Hyme- 

 noptera 



Diptera 



Disease 



1922 



1923-26 1 



Number 

 1 



Percent 

 100 



Percent 

 



Percent 

 



Percent 



100 



1927 _ 



86 

 1 



13 

 



4 

 





 



17 



1928 



1929-32 ! 







1933 



152 

 123 

 243 



2 



4 



26 



14 



. 8 

 1 





 

 4 



16 



1934 



5 



1935 



31 



1936 L. 





1937 



1938 



203 



127 



46 

 67 





 5 



2 

 3 



48 

 75 



1939 i 





1940___ 



154 



19 



14 







33 



1 No collections. 



Parasites and disease organisms reared were as follows: 



Hymenoptera — Apanteles militaris (Walsh), Netelia ocellata (Vier.), Rogas 

 terminalis (Cress.), Catolaccus aeneoviridis (Gir.), as a hyperparasite of 

 Apanteles militaris. 



Diptera — Archytas basifulva (Walk.), Archytas apicifera (Walk.), Achaetoneura 

 melalophae Allen, Euphorocera sp. probably tachinomoides (Tns.), Winthemia 

 quadripustulata (F.), Wagneria sp. probably carbonaria (Panz.). 



Disease organisms — Metarrhizium anisopliae (Metsch), unidentified wilt. 



