POPLAR CATERPILLARS. 447 



Professor Riley thus sums up the leading points in the history of this 

 pest (Bull. 10, Div. Ent.) : 



The White-marked Tussock moth has a very beautiful hairy larva or caterpillar 

 marked with black and yellow and red. The feniale cocoons are to be found during 

 the winter on the trees and upon neighboring fences and tree-boxes, and each 

 cocoon is plastered with a number of eggs, protected by a white, frothy, ghitinous 

 covering. The eggs hatch in spring and the young worms feetl upon the fresh leaves. 

 The males spin their cocoons after three molts and the females after four. The moths 

 issue in July, pair and lay eggs for a second brood of worms, which in turn transform 

 and bring forth moths in October, the eggs from which hibernate. The male moth 

 is active, with ample wings, which are brown, with a conspicuous white spot, while 

 the female is pale and wingless, and only crawls out of her cocoon to lay her eggs 

 thereon and die. This species is never found on evergreens, and is chiefly injurious 

 to elms and maples, and prefers large and old trees to young ones because of the 

 greater shelter which they offer for its cocoons. In Washington it is yet chiefly con- 

 fined to our parks, and it has not begun to be as injurious as in cities like Philadel- 

 phia and Baltimore, where the trees are older and larger. Two probable egg-para- 

 sites and seven parasites of larva and pupa are known to me. 



Mrs. Dim mock gives a summary of what is known of its history 

 (Psyche, iv^, p. 280) as follows: 



Orgyia leucostigma Abb. and Smith (Nat. Hist. Lepid. Ins. Ga., 1797, v. 2, p.l57, pi. 

 79). Harris (Rept. Ins. Injur. Veg., 1841, pp. 261-263) describes the eggs, larva, and 

 imago of this species; apple and ^osa are given as food-plants. The same author 

 (Treatise on Ins. Injui-, Veg., 1862, pp. 366-368) figures and describes the eggs, larva, 

 cocoon, and male and female imiigos, and adds Aesculus hippocastaneum to the food- 

 plants; later (Entom. Corresp., 1869, p. 291) he adds further Salix, Celtis, and Carya 

 to the food-plants. Fitch (First and Second Rept. Ins. N. Y., 1856, pp. 202-220) de- 

 scribes the difi'erent stages of this species, noting in addition to food-plants mentioned 

 above, Ulmus, Acer, Quercus, and plum. Riley (First Ann. Rept. State Entom. Mo., 1869, 

 pp. 144-147) figures and describes briefly the eggs, larva, pupa, cocoon, and male and 

 female imagos ; the figure of the larva is repeated in Amer. Entom., Sept. 1870, v, 2, 

 p. 306. Saunders (Can. Entom., Apr. 1871, v. 3, pp. 14-15) repeats Riley's figure of 

 the larva, and describes the egg and egg-mas. Packard (Bull. 7, U. S. Entom. Comm., 

 1881, p. 239) repeats Riley's figures of the different stages of this species. Coleman 

 (Papilio, November and December 1882, v. 2, pp. 164-166) describes some variations 

 in the coloration of the larvie. Clarkson (Can. Entom., Sept. 1883, v. 15, p. 168) 

 mentions that this larva particularly attacks the silver-leaf Populus, and calls atten- 

 tion to the fact that ichneumons oviposit in cocoons of this species. The larva feeds 

 upon Betula alba and B. lenta. 



13. Orgyia antiqua Linn. 



The larva of this common European species, which I have found on 

 the aspen and poplar-leaved birch, as well as the thorn tree, differs 

 from that of 0. leucostigma in having three j^airs of lateral tufts, one in 

 front arising from the segment next to the head, and two others, a small 

 white one, arising from the first abdominal segment, and a larger 

 longer black pencil arising from the second segment ; while the body is 

 black. I observed the moth many years ago flying about the house early 

 in September, if I remember correctly. The caterpillar becomes full- 

 fed about the middle of August and remains in the pupa state a few 

 days, inclosed in a loose cocoon, on the outside of which the eggs are 

 laid by the wingless female. 



