118 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



Fig. 37.— Forest tent-caterpillar; 6, female moth ; c, d, eggs 

 of the forest tent-caterpillar. (After Riley.) 



segment. On the hinder part of each wing are three crinkled and more or less pale, 

 orange-yellow lines,. which are edged with black. On each side also is a continuous 



audsorae what broader stripe of 

 the same yellow color, similarly 

 edged on each side with black. 

 Lower down on each side of tlie 

 body is a paler yellow or cream- 

 colored stripe, the edges of which 

 are more jagged and irregular 

 than those of the cme above it. 

 Length 1.50 inches. (Fitch.) 



The male moth usually measures 

 1.20 across its spread wings. Its 

 thorax is densely coated with soft 

 hairs of a nankin-yellow color. 

 Its abdomen is covered with 

 shorter hairs, which are light um- 

 ber or cinnamon brown on the 

 back and tip and paler or nankin- 

 yellow on the sides. The antennae 

 are gray, freckled with brown 

 scales, and their branches are very 

 dark brown. The face is brown with the tips of the feelers pale gray. The fore 

 wings are gray, varied more or less with nankin yellow, and they are divided into 

 three nearly equal portions by two straight, dark-brown lines, which cross them 

 obliquely, parallel with each other and with the hind margin. The space between 

 these lines is usually brownish and darker than the rest of the wing, being quite often 

 of the same dark-brown color as the lines, whereby they become wholly lost. Some- 

 times the hind stripe is perceptibly margined on its hind side by a pale-yellowish line. 

 The fringe is of the same dark-brown color with the oblique lines, with two whitish 

 alternations toward its outer end. But sometimes it is of the same color with the 

 wings and edged along its tips with whitish. The hind wings are of a uniform pale 

 umber or cinnamon brown, sometimes broadly grayish on the outer margin, and across 

 their middle a faint darker brown band is usually perceptible, its edges on each side 

 indefinite. The fringe is of the same color with the wings or slightly darker and is 

 tipped with whitish. The under side is paler umber brown, the hind wings often gray, 

 and both pairs are sometimes crossed by a narrow dark-brown band, which on the 

 hind wings are curved outside of the middle. All back of this band on both wings 

 is often paler, and more so near the baud. 



The female is 1.75 in width, and, in addition to the shortness of the branches of her 

 antennae, differs from the male in her fore wings, which are proportionally narrower 

 and longer, with their hind margin cut off more obliquely and slightly wavy along its 

 edge. Hence, also, the dark-brown lines cross the wings more obliquely, the hind one 

 in particular forming a much more acute angle with the outer margin. And all the 

 wing back of this line is sometimes paler or of a brownish-ashy color. And the fringe 

 of these wings has not the two whitish alternations which are often so conspicuous 

 in the male. The head and forepart of the thorax is cinnamon brown. The abdomen 

 IS black, clothed with brown hairs, though very thinly so on the anterior part of each 

 segment, where these hairs are intermingled with silvery gray scales. (Fitch.)* 



* The following references are copied from Mrs. A. K. Dimmock's Insects of Betula, 

 in Psyche, iv, 275: 



Clisiocampa sylvattca Harris (Rept. Ins. Injur. Veg., 1841, pp. 271-272) [= C. disstria 

 Hiibn.]. Harris (op. cit., p. 272) describes the larva of this species, giving as food- 

 plants Quercus, Juglans, and apple; later (Treatise on Ins. Injur. Veg., 1862, pp. 

 375-376, pi. 7, figs. 18, 19) he repeats the description and adds a colored figure of the 

 larva and imago, adding wild cherry to the food-plants; again he describes (Entom. 



