CUTWORMS, ARMYWORMS, AND RELATED SPECIES 43 



a rule the larvae are solitary, probably because, on hatching, they are 

 capable of spinning down on silken threads and are thus dispersed by 

 the wind. 



Seasonal history. — There are three to four generations a year. In 

 the central Great Plains the winter is passed in the pupal stage. 

 Adults were captured at light traps from late in March to the end of 

 October, the flight being heaviest in July and August. This species is 

 difficult to rear in captivity, owing to the prevalence of a disease that 

 kills the larvae quickly. Observations indicate, however, that the 

 spring generation produces adults in July and August. The summer 

 generation develops rapidly, and adults from this generation appear in 

 September. These adults give rise to the third generation that includes 

 overwintering pupae. The eggs are deposited in masses, which are 

 covered with scales from the female's body. They were most 

 frequently found on the under side of leaves. 



Life cycle. — Spring generation: This generation was not reared in 

 this work. 



Summer generation: The summer generation develops rapidly, 23 

 to 25 days having been required from egg to adult in one reared series. 



Fall generation: Eggs deposited on September 18 hatched in 3 days. 

 The larvae pupated from October 22 to 25 and passed the winter in 

 that stage. Adults began emerging on March 27 and continued to 

 April 1L 



Reproductive capacity. — Two dissected females contained 2,189 and 

 1,622 eggs. 



Natural enemies. — Of 72 larvae reared, 6 percent were parasitized by 

 Hymenoptera and 7 percent by Diptera and 17 percent were killed by 

 an unidentified wilt disease. The following parasites were reared: 



Hymenoptera — Euplectrus comstocki How., Chelonus texanus Cress. 

 Diptera — Winthemia quadripustulata (F.). 



Laphygma exigua (Hubner) 



Beet Armyworm 

 (Fig. 4, P) 



Distribution. — The beet armyworm is distributed throughout the 

 Gulf States and westward to the Pacific coast. It is also recorded from 

 Kansas and Nebraska. 



Economic status. — This species is of minor economic importance in 

 the central Great Plains. 



Food plants and larval habits. — The beet armyworm is a general 

 feeder. In Kansas the larvae are minor pests of sugar beets, but at 

 times are abundant in alfalfa. They are diurnal, feeding actively 

 during the day. Their greyish green blends with the green of the host 

 plants, so that the larvae are difficult to see when resting on a stem. 



Seasonal history. — There are probably two generations a year of 

 this species in Kansas. Adults were taken at lights from early in May 

 to late in October and were most numerous in July and August. 

 Presumably they pass the winter in the pupal stage. 



Natural enemies. — Of 120 reared larvae, all collected from alfalfa, 

 18 percent were parasitized by Hymenoptera and 0.8 percent by 



