Zebra Caterpillar Leaf-eating Beetles 



NATURE OF INJURY 



The zebra caterpillar bears the distinction of being the first insect 

 reported as damaging beets in the United States.* While it seems to 

 prefer vegetable crops, especially beets, and cabbage, turnips, and other 

 cruciferous plants in general, yet it feeds upon field crops and even the 

 leaves of trees and shrubs. 



METHODS OF CONTROL 



Dr. Chittenden* states that this insect yields readily to sprays of 

 arsenicals. Paris green or arsenate of lead, the former at the rate of 2 to 

 3 pounds and the latter at 4 to 6 pounds dry or 8 to 12 pounds of the 

 paste, to each 100 gallons of water, will give satisfactory results. 



DESCRIPTION 

 The Egg 



The eggs are deposited in clusters of from several to as many as a 

 hundred or more, usually on the under side of the leaves of the food plants. 



The Caterpillar 



At first the worms are whitish in color with dark heads and several 

 dark spots scattered over the body. While small they feed in compact 

 groups, but after several days the skin is shed and the caterpillars take on 

 the colors of the adult worm (Fig. 1 1, Plate III, Page 15) and gradually 

 become scattered. When disturbed the worms coil up and fall to the 

 ground. 



The Moth 



The moth is about the size of the adult western army cutworm (Fig. 

 3, Plate I, Page 11). The fore wings are a chestnut brown shaded with 

 purplish brown. The hind wings are whitish with pale brown margins. 



LIFE HISTORY 



The zebra caterpillar passes the winter in the pupal stage in the 

 ground. The first moths appear in May and June. In moderate tem- 

 peratures the eggs hatch in about six days. The worms feed four or five 

 weeks and then change to pupae, in which form they remain for about 

 sixty days. The moths of the second brood appear in late August or 

 September. The second brood of worms feeds during the fall, the change 

 from worm to pupa taking place before winter sets in. 



NATURAL ENEMIES 



This caterpillar appears to be especially attractive to the various 

 parasitic insects infesting caterpillars in general. Many are killed by 

 fungous diseases, while birds no doubt destroy them in large numbers. 



2. LEAF-EATING BEETLES 



There is a family of variously colored beetles of small or moderate 

 size, the members of which are called "leaf-beetles" because they feed 

 upon the leaves of plants in both the adult and larval stages, with a few 



*Dr. RH. Chittenden. "A Brief Account of the Principal Insect Enemies of the Sugar Beet." Bulle- 

 tin No. 43. Division of Entomology. U. S Department of Agriculture (1903). 



88 



