SHADE TREE INSECTS 31 



occasionally severely injured. The caterpillars are somewhat gregarious and 

 usualh- defoliate a branch or two before moving to another. If food is plentiful 

 they do not spread rapidly. The\' may be fairly abundant in one locality for 

 several j'ears while near by they may be practically unknown. 



Description. The moth is bright reddish-yellow in color. The forewings have 

 numerous tiny dark spots and a single small but distinct white spot near the for- 

 ward edge. The female has a wingspread of about 2^/^ inches. The male is 

 smaller (about 1 }/2 inches) and slightly darker in color. 



The eggs are round, about 1/25 inch in diameter, somewhat flattened, and may 

 vary from clear white to dull coral red. They are laid in large irregular masses 

 on the under side of the leaves. 



The newly hatched caterpillar is pale yellow and its large head and legs are 

 black. Two stiff black horns arise from the top of the second bod>- segment just 

 back of the head. Pale bristles are present on the remaining body segments. 

 The mature caterpillar is about 2 inches long and black in color, with eight orange- 

 }ellow stripes on the back and sides. The body has many short, sharp spines; and 

 two black, slightly curved horns about }.i inch long arise from the top of the 

 second body segment. 



The pupa is a dark brown, rough, spined object, about 1 inch long and is en- 

 closed in an earthen cell about 3 or 4 inches below the surface of the soil. 



Life History. The moths appear about the second week in June and begin 

 laying their eggs in large irregular clusters on the under side of the leaves. There 

 are usually from 200 to 300 eggs in a single cluster but 500 or more may be found. 

 The egg-laying period may last almost a month. The eggs hatch in about a week 

 or 10 days. The tiny young caterpillars begin to feed gregariously on both sur- 

 faces of the leaves, consuming all except the network of veins. Later the older 

 caterpillars may eat all but the main vein. They usually defoliate a branch or a 

 tree before moving on to another. They molt five times but, because of the 

 length of the egg-laying period, caterpillars of almost all stages may be found 

 together on a single tree during the summer. By early fall most of the larvae are 

 mature, and about the second or third week in September may be found crawling 

 to the ground where they burrow 3 or 4 inches beneath the surface and construct 

 a simple earthen cell in which they transform to the pupal stage and pass the 

 winter. There is one generation a year in the northern part of the insect's range 

 but in the southern part there may be two. 



Control. When but a few branches are infested and they can be reached, the 

 clusters of caterpillars may be collected and destroyed when young. For larger 

 infestations a thorough application of lead arsenate, used in the proportion of 4 

 pounds of the powder to 100 gallons of water with the addition of 2 pounds of 

 flour or 1 pound of calcium caseinate, is recommended. This spray should be 

 applied as soon as the >oung caterpillars begin to appear. 



Bailey, H. L. Vt. Dept. of Agr. Bui. 35:27. No date. 

 Felt, E. P. N. Y. State Mus. Mem. 8(1) :306-310. 1905. 

 Houser, J. S. Ohio Agr. Exp. Sta. Bui. 332:249-251. 1918. 

 Lintner, J. A. N. Y. State Ent. Rpt. 5:192-200. 1889. 

 McDaniel, E. I. Mich. Agr. Exp. Sta. Spec. Bui. 243:57. 1933. 

 Packard, A. S. Fifth Rpt. U. S. Ent. Comm., pp. 124-125. 1890. 



The two following species are closely related to the orange-striped oak worm and 

 may possibly be confused with it so a brief account of them is given. 



