BIRCH CATERPILLARS. 489 



1869, V. 1, p. 48) calls attentiou to the squeaking noise produced by the larva of this 

 and of other species of *Sme?-i«<A)ts. Lintner (Entoui. Contrib. [No. 1], 1869, p. 56) 

 gives Pruniis pennsylvanica and Cratcegus as food plants of the larva. Mann (Psyche, 

 September and October 1877 [8 Mar. 1878], v. 2, pp. 69-72) compares descriptions of 

 the larva of this and of other species of Smerinihus, giving Acer as food-plant of the 

 larva of S. excwcatus. Goodell (Psyche, July [Doc] 1882, v. 3, p. 368) describes egg 

 and first larval stage of this species. Fletcher (Can. Entom., Nov. 1883, v. 15, pp. 

 203-204) gives as food-plants apple, plum, wild cherry, Populus halsamifera and P. alba, 

 and further states that the larvsB varied much in coloration. Saunders (Can. Entom., 

 Jan. 1884, v. 16, pp. 9-11) describes and figures the last stage of the larva and the 

 imago. Fischer {op. cit., p. 17) adds Tilia and Salix to the food-plants. In Cam- 

 bridge, Mass., the larva of this species is not rare on low shrubs of Betiila alba, where 

 it occurs throughout August and September. The larvjie, as observed ou Betula alba, 

 exhibit no variation. They are somewhat difificult to rear ; of thirty-eight larvaj, of 

 which rearing was begun, eight were put in alcohol for preservation ; three produced 

 images (2 males and 1 female) ; sixteen died without apparent parasitism, while eleven 

 were killed by Thyreodon morio, of which ichneumon only two reached the imago state. 

 One of the pupae of Thyreodon produced a large number of minute hymenoptera — sec- 

 ondary parasites. The egg of S. excwcatus often harbors very minute hymenopterous 

 parasites ; more than thirty of these hymenoptera sometimes emerge from a single egg 

 of Snieriuthus, a fact that will give an idea of their microscopical minuteness. 



14. The Hickory Tussock-worm. 



Halesidota caryce (Harris). 



1 found August 28, at Brunswick, Me., a whole brood of these cater- 

 pillars on a birch tree, almost covering both the upper and lower sides 

 of a leaf. 



• 15. The Wooly Bear. 



Spilosoma virginica (Fabr.). 



The " wooly bear" caterpillar of this species is a general feeder, and 

 is said, among other trees which Mrs. Dimmock enumerates below, to 

 feed on the white birch. 



She also adds to the list of birch-feeding insects Pyrrharctia isabella* 

 (under the name ^^ Spilosoma isabella^^), though as it apparently has 

 only fed on this tree while in confinement, we should as yet scarcely 

 regard it as affecting this tree. 



S2}Uosoma virginica Fabr. (Syst. Entom., Suppl., 1775, p. 437). Harris (Rept. Ins. 

 injur. Veg., 1841, p. 247, 248) describes the larva and imago, stating that the larva 

 feeds on leaves of Plantago, Pisam, Phaaeolus, Zea mays, Graminea', Vitis, Ribes rubrum 

 and R. grossularia ; later (Treatise ou Ins. injur. Veg., 1862, p. 349-351) he adds a 



* Sjnlosoma isabella Abb.-Smith (Nat. Hist. Lepid. Ins. Ga., 1797, v. 2, p. 131, pi. 66). 

 Harris (Rept. Ins. injur. Veg., 1841, p. 252, 253) describes larva and imago giving 

 TrifoUum, Taraxacum dens-leonis, and narrow-leaved Plantago as food-plants; to this 

 he adds (Treatise ou Ins. Injur. Veg., 1862, p. 35.5, 356) a figure of the larva. Walsh [?} 

 (Pract. Entom., June, 1867, v. 2, p. 103) gives apple as a food-plant of the larva. 

 Riley (Amer. Entom.. April, 1870, v. 2, p. 182) figures and briefly describes the larva, 

 pupa, and imago, mentioning only grass as a food-plant of the larva; later (4th Ann. 

 Rept. State Entom. Mo., 1872, p. 143, 144) he reprints these figures. Riley's figures, 

 with a brief description, are again repeated by Saunders (Can. Entom., April, 1873, 

 V. 5, p. 75-77, and Ann. Rept. Entom. Soc. Ontario, 1873, p. 22, 23), and Westcott 



