38 



MASS. EXPERIMENT STATION BULLETIN 353 



caterpillars have three pairs of very small legs, they have the appearance of being 

 legless. Along the under side of the body is a series of fleshy elevations or sucking 

 disks which serve for legs. When in motion the larvae glide along in a charac- 

 teristic fashion, the lower surface of the body being pressed close to the object 

 over which they move. Several species have spines which upon contact with the 

 skin, cause severe irritation. 



When full grown, a caterpillar spins a dense, egg-shaped or round cocoon of 

 brown silk, usually between leaves. At one end of the cocoon is a cap which the 

 moth pushes aside when it emerges. 



The moths are medium to small in size and have stout bodies. The several 

 species vary greatly in appearance. 



Saddleback Caterpillar on Leaf. 



Courtesy, Robert L. Coffin. 



Larva of Hag Moth. 



Greatly enlarged. 



Control. Whenever these caterpillars become annoying they may be con- 

 trolled by spraying the foliage with lead arsenate at the rate of 4 pounds to 100 

 gallons of water, with 2 pounds of flour or 1 pound of calcium caseinate added to 

 increase adhesiveness. 



Britton, W. E. Conn. State Ent. Rpt. 30:462. 1930. 



Comstock, J. H. Introduction to Entomology, pp. 608-610. 1933. 



Felt, E. P. N. Y. State Mus. Mem. 8(2) :527-529. 1906. 



Harris, T. W. Insects Injurious to Vegetation, pp. 419-422. 1862. 



Packard, A. S. Fifth Rpt. U. S. Ent. Comm. pp. 143-148. 1890. 



Red-Humped Caterpillar 



Schiziira concinna S. & A. 



This insect is distributed over practically the entire United States and parts 

 of Canada. It is commonly considered to be an orchard pest but it also attacks 

 the foliage of a number of forest and shade trees including birch, willow, aspen, 

 butternut, walnut, and others. The caterpillars, which appear in midsummer, 

 feed in colonies, especially when young, and may defoliate a single branch or an 

 entire tree. 



Description. The moth is colored an inconspicuous grayish-brown. The 

 female has a wingspread of about IJ^ inches; the male slightly less. 



The eggs are white, almost round, and occur in masses of about 100 on the 

 under side of leaves. 



The full-grown caterpillar is about 1 inch or slightly over in length, is striped 

 with narrow black and yellow lines running lengthwise along the bod}', and has a 

 double row of black spines along the back. The body tapers slightly toward the 

 rear end. The head and a conspicuous hump on the fourth body segment are a 

 bright red. 



