36 



CIRCULAR 



U. S. DEPT. OF AGRICULTURE 



Table 4. — Mortalities oj larvae oj Peridroma margaritosa caused by 

 various natural enemies, 1920-4-0 





Larvae 

 observed 



Larvae killed by — 



Total 



Year 



Hyme- 

 noptera 



Diptera 



Xema- 

 toda 



Disease 



mortal- 

 ity 



1920___ 



Number 



65 



2 



2 



1 



Percent 



14 











100 



Percent 

 3 

 

 

 



Percent 

 

 

 

 



Percent 

 2 

 

 

 



Percent 

 19 



1921 







1922 







1923. 



100 



1924-26 1 _ 





1927 



4 























1928-32 1 . 





1933_ 



1 



2 



510 





 

 1 



100 







11 





 

 .6 





 



7 



100 



1934 







1935 



1936 i 



20 



1937 _ 



732 



101 

 30 



175 



6 

 53 

 33 



18 



10 



43 

 25 



. 3 



1 

 

 



6 



14 



3 



7 



22 



1938 



75 



1939__ 



79 



1940 



50 







1 No collections. 



The following parasites and disease organisms were reared from 

 field-collected larvae : 



Hymenoptera — Apanteles griffini Vier., Apanteles militaris (Walsh), 

 Campoletis perdistinctus (Vier.), Opinion sp., Ophion ancyloneura Cam., 

 Meteorus vulgaris (Cress.). 



Diptera — Archytas analis (F.), A. apicifera (Wlk.), Schizocerophaga sp., 

 Salmacia sp. probably sequax (Will.), Poecilanthrax halcyon (Say). 



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



Amathes (formerly Noctua) c-nigrum (Linnaeus) 



Spotted Cutworm 

 (Figs. 4, U; 7, O) 



Distribution. — This species is recorded from Canada and in the 

 United States as far south as Virginia, Tennessee, Kansas, and 

 Arizona; also from Alaska, Europe, and Asia. 



Economic status. — It is of minor economic importance in the central 

 Great Plains. In northeastern United States it is an important 

 garden pest. 



Food plants. — The spotted cutworm is a general feeder and is 

 reputed to be one of our most destructive cutworms in its range of 

 abundance. In the central Great Plains it has never appeared in 

 damaging numbers, and is collected chiefly in pasture grasses and 

 wastelands. 



Seasonal history. — There are apparently two generations a year in 

 Kansas. Two distinct periods of adult flight were evident from light- 

 trap records for Manhattan, 1935-37, one beginning the first week in 

 May and extending to the middle of June, and the other beginning 



