CUTWORMS^ ARMYWORMS, AND RELATED SPECIES 19 



Euxoa velleripennis (Grote) 



Distribution. — Adults of E. velleripennis were collected at lights in 

 Manhattan, Kans., and Lincoln and Scottsbluff, Nebr. Dirks (7) 

 reports this species from Maine; Tietz (16), from Pennsylvania. 



Economic status. — This species is of no economic importance in the 

 central Great Plains. 



Food plants. — The preferred hosts are not known. One larva was 

 found in pasture land near Chadron, Nebr. 



Seasonal history. — Although no details are known, the species prob- 

 ably has only a single generation annually. Adults were collected 

 at lights in September and October. One larval specimen was taken 

 on May 2, 1927; it pupated on May 23; and the adult emerged on 

 June 11. This development would indicate the possibility of estiva- 

 tion as an adult. 



Chorizagrotis auxiliaris (Grote) 



Army Cutworm 

 (Figs. 2, L; 4, A; 7, A) 



Distribution. — This species is distributed throughout the semiarid 

 region of the Great Plains, sometimes extending its range to eastern 

 Kansas. The larvae have been reported in destructive numbers 

 from Texas, Oklahoma, Kansas, Nebraska, South Dakota, North 

 Dakota, Montana, Wyoming, Colorado, New Mexico, Utah, Idaho, 

 and Oregon. Although heavy nights of adults have been reported 

 from Wisconsin and Iowa, the larvae have not been recorded east of 

 the Mississippi River. 



Economic status. — The species is of major economic importance in 

 the semiarid regions of the Great Plains. 



Food plants and larval habits. — The larvae feed on a wide variety 

 of plants, although winter wheat and alfalfa are the principal crops 

 damaged. When the larvae are numerous they assume the army 

 habit and, advancing across a wheat or alfalfa field, entirely consume 

 the plants above ground. In many instances the larvae have migrated 

 into such fields from adjacent pasture lands. At other times the 

 infestation apparently originated within the crop attacked. 



Seasonal history. — The army cutworm has but a single generation 

 a year. The eggs are deposited in the soil late in September and during 

 October. Ovipositing females move swiftly along the ground, stopping 

 frequently to insert the ovipositor into small cracks in the soil. The 

 eggs hatch in 1 to 2 weeks, and the young larvae feed until cold 

 weather. They pass the winter as partly grown larvae, and no doubt 

 do some feeding in occasional warm periods during the winter months. 

 As soon as the weather warms up late in February or early in March 

 the larvae resume active feeding, and it is during this time that they 

 do the greatest damage. The larvae become full-grown early in April 

 and enter the soil for pupation. The adults begin to appear in May, 

 and in years of abundance are often a nuisance in dwellings and about 

 lights during most of June. This flight immediately after emergence 

 subsides suddenly, and in the central Great Plains the army cutworms 

 estivate as adults. 



Adults are seen at high altitudes in the Rocky Mountains. On 



