440 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 5 



the first, at times almost olive in color instead of green. , The larvae 

 live for two weeks but do not eat during the last three or four daj's. 

 During this period they are very restless and active, especially between 

 ten o'clock a. m. and three o'clock p. m., until they have found a 

 suitable place to pupate. The cocoon is twice the length of the larva 

 and three times the length of the pupa. 



The injury is done so quickly, sometimes within 36 hours, that the 

 owner of the field is led to believe that the worms migrated from the 

 adjoining fields during the night. No general migrations of the larvje 

 have been observed. 



A peculiarity of the attacks by this insect is that in nearly every 

 instance the heavy injury is well into the field, rarely ever along the 

 edge. A small area of infestation will apparently spread each day, 

 due to the fact that the moths in depositing their eggs work outward 

 from their place of emergence. Cases ha!ve been noted where the 

 worms in the center of the field had burrowed into the ground, while 

 on the outer edges of the field they were still active. The injuries 

 appear to be worse on fields that were exceedingly weedy the previous 

 season. No difference in the infestation of beets on light soil and on 

 heavy soil has been noted. Frequently a field may be badly infested 

 and the adjoining one will be unharmed. On individual plants the 

 young tender leaves were always last to be eaten. Only in extreme 

 infestation are the beets eaten, and almost never is the entire leaf- 

 crown destroyed. Beets that have been badly eaten usually send forth 

 three or four small crowns of leaves. 



The Pupa. Unfortunately it is hard to obtain uninjured pupse. 

 They are about 12 mm. long and of a bright bronze color. Pupation 

 takes place in the ground in a silken cocoon, usually one-half to three- 

 fourths of an inch below the surface. It is very tough and is covered 

 with a layer of soil. The cocoon is three times the length of the pupa 

 in the summer broods and four times in the over-wintering brood. 



Life History. The hibernating larvae pupate in May and soon 

 emerge as moths. These give rise to the June brood of larvae, seldom 

 observed and not very abundant. These appear on weeds such as 

 goosefoot (Chenopodium) and pigweed (Amarantus). Sometimes 

 alfalfa serves as food for this first brood of larvae. 



The second brood of larvae is at its height the later half of July. 

 This brood is very short lived, requiring only two weeks for maturity 

 of the larvae and the appearance of the moths. The larvae of this 

 brood pupate almost immediately upon entering the ground. This 

 is often the destructive brood of the season as it feeds entirely upon 

 beets. 



The third brood of larvae reaches its maximum the latter half of 



