CUTWORMS, ARMYWORMS, AND RELATED SPECIES 



21 



Natural enemies. — During the investigation of this important species 

 outbreaks never occurred in two successive years in a given locality. 

 Field collections of the larvae were made at every opportunity over a 

 period of 20 years. As a result a knowledge of parasitism and disease 

 was gained from rearing larvae taken in various localities in the central 

 Great Plains under conditions of both abundance and scarcity. These 

 data are given in table 2. 



Table 2. — Mortalities of larvae of Chorizagrotis auxiliaris caused by 

 various natural enemies , 1921-4-0 





Larvae 



ob- 

 served 



Larvae killed by — 



Total 



Year 



Hyme- 

 noptera 



Dip- 

 tera 



Nema- 

 toda 



Disease 



mortal- 

 ity 



1921 



Number 

 87 

 88 

 16 



1 

 54 



6 

 91 



8 



Percent 

 5 



11 

 6 

 

 9 



33 

 6 

 



Percent 

 2 

 

 

 

 

 

 2 

 



Percent 

 1 

 

 

 

 

 

 

 



Percent 

 

 6 

 

 

 6 

 

 1 

 



Percent 

 8 



1922 



17 



1923 



6 



1924 







1925 



15 



1926 



33 



1927 



9 



1928 







1929-32 i 





1933 



5 

 211 



378 

 129 

 140 

 508 

 6 

 152 







21 



13 



18 



5 



9 







5 







4 



. 3 



4 



10 



10 







. 6 





 

 



. 8 

 



. 2 

 

 







41 



57 



17 



9 



10 







3 







1934 ■ 



66 



1935 _• 



70 



1936 



40 



1937 



24 



1938 



29 



1939 







1940 



9 







1 No collections. 



The parasites and disease organisms reared from larvae collected in 

 various localities were as follows: 



Hymenoptera — Eubadizon sp., Meteorus vulgaris (Cress.), Ophion sp., Ophion 

 n. sp., Exetastes lasius Cress., Exetastes n. sp., Macrocentrus inco'mpletus 

 Mues., Berecyntus bakeri var. bakeri How., B. bakeri var. euxoae Gir., 

 Rogas sp., Netelia ocellata (Vier.), Netelia sp., Apanteles griffini Vier., and 

 Microplitis feliiae Mues. 



Diptera — Tachinidae (unidentified), Bombyliidae (unidentified), Poecilan- 

 thrax n. sp., Anthrax willistoni Coq., Neophorocera claripennis (Macq.). 



Disease organisms — Beauveria sp., Isaria sp., Metarrhizium anisopliae 

 (Metsch), Sorosporella uvella (Krass), and an unidentified wilt. 



Feltia subgothica (Haworth) 



Dingy Cutworm 

 (Figs. 2, B; 4, D) 



Distribution. — The dingy cutworm is one of the most widely dis- 

 tributed species. It is found in Canada and throughout the northern 

 United States and southward to include Virginia, Tennessee, Mis- 

 souri, Oklahoma, Colorado, Utah, Texas, and New Mexico. 



