96 BULLETIN 190, UNITED STATES NATIONAL MUSEUM 



in castaneae the collar is black and the tibia is tufted with yellow only 

 at the posterior spurs. 



The United States National Museum has a fine representation of 

 castaneae, in large part obtained by rearing. This is fortunate, as the 

 species is threatened with early extinction following the extermination of 

 its food plant, the American chestnut, by the chestnut blight. Only com- 

 paratively few diseased and struggling trees remain. 



6'. castaneae is a borer in the tree trunks, preferably attacking bruised 

 places. The life cycle is annual. Wintering in its burrow, the larva 

 constructs a rough, oblong cocoon of chips in spring. The moths emerge 

 late in May or in June or July. At the beginning of the twentieth century 

 the insect was fairly common in the eastern Atlantic Coast States, in the 

 Southern States, and inland, ranging north to Canada, wherever the 

 chestnut occurred. No records have been received in recent years. Quite 

 likely there are stray specimens in collections unrecognized and confused 

 with pictipes. 



SYNANTHEDON VIBURNI Eneelhardt 



Plate 23, Figure 142 



Synanthedon vihurni Engelhardt, Bull. Brooklyn Ent. See, vol. 20, p. 65, 1925. — 

 McDuNNOUGH, Check list of the Lepldoptera of Canada and the United States, 

 pt. 2, No. 8721, 1939. 



Male. — Antennae blue-black, slightly dilated apically and with a few 

 pale scales before the tips, pectinations very short and fine. Tongue well 

 developed, spiral. Labial palpus with a smooth, even, pale-yellow brush ; 

 third joint pointed, black. Face black. Head black, with long hair, which 

 is yellow and black mixed on top. Collar pale yellow. Thorax blue-black, 

 narrowly banded with pale yellow laterally above and with a broad patch 

 of the same color beneath before base of wing. Wings lustrous hyaline ; 

 forewing with costa, transverse mark, and narrow outer margins blue- 

 black, underside shaded with pale yellow; hindwing with margins and 

 cilia very narrow, rusty black. Legs steel blue, tibia smooth, with a 

 whitish, short tuft at the spurs ; tarsi white at the joints. Abdomen bright 

 steel blue, second segment narrowly banded with white above, fourth 

 segment broadly marked with white at the sides, no bands beneath ; anal 

 tuft clearly wedge- or halberd-shaped, edged with white at the sides. 



Female. — Similar to male. Antennae simple, broadly banded with pale 

 yellow or whitish before the tip ; outer wing margins broader than in the 

 male; anal tuft straight, narrow. 



Expanse: Male 16 to 18 mm., female 18 to 22 mm. 



Distribution. — Recorded only from Long Island, N. Y. 



Type. — Male, from Woodhaven, N. Y. In the United States National 

 Museum. 



Remarks. — Biologically vihurni is not closely related to any of the 

 several species to which it bears a close superficial resemblance. When 



