THE STRIPED BEET CATERPILLAR. 17 



Only nine moths of the second generation developed in the cages 

 and, unfortunately, all were females. They deposited hundreds of 

 eggs which w^ere infertile, failing to hatch. Judging from the records 

 which were obtained the previous fall it may be concluded that there 

 are three full generations each year. 



EGG-LAYING RECORD. 



On September 17, 1911, a female moth was captured and placed in 

 a cage. Eggs were deposited as follows: 



Eggs deposited. 



September 19 123 



September 20 114 



September 21 82 



September 22 78 



September 23 82 



September 24 25 



Total 504 



The moth died September 25. 



NATURAL ENEMIES AND OTHER CHECKS. 



As previously noted, the pupre are formed in earthen cells, near the 

 surface of the soil, in the beet fields. When the beets are cultivated 

 or plowed out at harvest time, many of the cells are broken open and 

 the pupa? crushed or exposed to the weather. This is an eiRcient 

 check. 



During the winter of 1911-12 the minimum temperatures at Eocky 

 Ford ranged from —15° to —26° F. This exceptionally cold weather 

 apparently killed man}^ pupse. 



In addition to these factors in control, there are several species of 

 parasitic and predaceous insects which serve to check the increase of 

 the Mamestra larva?. The following records were obtained at Kocky 

 Ford : 



Mlerodus inedms Cress., a braconid, was reared July 9, 1912. It is 

 a medium-sized red and black insect with dusky wings. 



Meteorus sp. (Chttn. No. 597), a smaller braconid, hone}' yellow in 

 color, was reared July 11. 



A still smaller species, a braconid (Chttn. No. 598), was reared 

 August 1, but not positively identified. The body is black, the an- 

 tenna' and legs are yellow^, and the abdomen is marked with yellow. 

 The larva; of this parasite feed externally, in a cluster, on the dorsal 

 surface of the Mamestra larva?. 



Phorocera claripennis Macq., a tachinid, was reared August 4. 

 This fly is a common cutworm parasite. 



PerUloides hloculata Fab., a pentatomid, was frequently found 

 stabbing the partl}^ grown Mamestra larv». 



