SHADE TREE INSECTS 37 



The young caterpillars feed on the lower leaf surface, eating small patches of 

 green tissue. As they grow older they devour all the leaf tissue except the larger 

 \'eins. 



Description. The moth has a wingspread of about \}/i to 1^/2 inches. The fore 

 part of the body (the thora.K) and the inner parts of the wings are light yellow. 

 The rest of the body and wings are a light reddish-brown. The fringes of the 

 wings are a darker brown. 



The eggs are oval, flattened, 1/16 inch long, and usually laid singl\- on the 

 lower surface of the leaves. 



The young caterpillars are creamy-white and semitransparent. As they grow 

 older they take on a greater variety of coloring and have markings of yellow, blue, 

 green, and purple. They have numerous hornlike projections covered with long, 

 brittle spines, the longer ones being at the extremities. 



The cocoons are }/2 inch long, broadly elliptical, smooth, ver>- hard, and usually 

 laid in the fork of a limb or twig. They are grayish-brow.i with white stripes or 

 markings, and somewhat resemble a bird's egg. 



Life History. The moths appear from late June through July and live from 

 7 to 10 days. They lay their eggs, usually singly, on the under side of the leaves. 

 The eggs hatch in about a week. The young caterpillars molt once and then 

 begin to feed on the foliage. Before becoming mature they molt several times, 

 taking on a greater variety of color at each molt. The young caterpillars eat 

 small green patches of leaf tissue; the older ones leave only the leaf veins. In 

 September or early October the mature caterpillar spins a very hard cocoon in 

 which to pass the winter. Transformation to the pupal stage takes place the fol- 

 lowing spring. There is only one generation a year. 



Control. The young caterpillars which usually appear from late July to mid- 

 August ma>" be satisfactorily controlled by spraAing with lead arsenate. This 

 should be used in the proportion of 3 pounds to 100 gallons of water, with ^ 

 pint of fish oil or raw linseed oil added as a sticker. After August 15 when most 

 of the caterpillars are about half grown and are more resistant to the spra^^ 4 

 pounds of lead arsenate to 100 gallons of water plus 1 pint of either oil should be 

 used. 



If the plants to be sprayed are near houses or other structures where oil cannot 

 be used, omit the oil and add 1 more pound of lead arsenate to each spray. 



On low-growing plants the cocoons may be collected and destroyed. 



Fernald, H. T. Hatch Exp. Sta. Mass. Agr. Col. Bui. 114. 1907. 

 Fernald. H. T., and Summers, J. N. Ent. News 18(8) :321-327. 1907. 

 Collins, C. W. Jour. Econ. Ent. 26(l):S4-57. 1933. 



Slug Caterpillars 



There are several species of slug caterpillars which occasionally attract atten- 

 tion because of their striking appearance. These include the hag moth cater- 

 pillar, Phobetron pitheciiim S. & A.; the saddleback caterpillar, Sibine stimulea 

 Clem.; the skiff caterpillar, Prolimacodes badia Wlk., and two other slug cater- 

 pillars, Euclea intermina Boisd., and Eiiclea delphinii Boisd. Some of these are 

 found on a variet>- of deciduous host plants in midsummer, but they rarely occur 

 in sufficient numbers to be regarded as anything more than natural curiosities. 



Description. The body of these caterpillars is short and thick, in several 

 species approaching an oval form. The body markings and structures vary con- 

 siderably in the different species and are often very striking. Although the 



