12G BULLETIN 190, UNITED STATES NATIONAL MUSEUM 



Female. — Same as the male, but with only three yellow abdominal 

 bands on segments 2, 4, and 6; anal tuft blunt, black, yellow in the 

 middle above. 



Expanse: Male 18 to 24 mm., female 22 to 26 mm. 



Distribution. — Eastern Atlantic Coast States, Maine to Maryland, the 

 Appalachian region of Virginia and the Carolinas, the Midwestern States 

 northward to Canada, New Mexico, and the Rocky Mountains. 



Type. — Male. In the American Museum of Natural History. 



Remarks. — T. sigmoidea is a borer in low-growing willows in bays, 

 along streams, and in depressions among sand dunes of coastal or lake 

 regions. The species is rather local, but when found infestations are apt 

 to be very heavy, swellings being produced on branches and canes, with 

 a number of larvae often in one branch. The moths, emerging late in 

 August and during September, do not visit flowers, and captures of 

 adults have been few. However, a good series can be obtained easily 

 by rearing from sections of branches collected in August, when the 

 larvae have pupated or are about to pupate in their galleries. Many 

 examples in the United States National Museum collection were reared 

 from sage willow, Salix tristis, growing in low places among sand dunes 

 at Amaganset, Long Island, N. Y., August and September 1913. Lake 

 Waccabuc, Conn., also furnished numerous rearing records. Another 

 good series has been reared from willow cuttings obtained along springs 

 in an open canyon near Estancia, N. Mex. The moths emerged late in 

 July and during August 1929. They are shaded a deeper orange on the 

 costa and outer wing margins but otherwise run true to the eastern type. 

 Captured moths are recorded from Manassas, Va., August 9, 1936 

 (Guerney) ; Black Mountains, N. C, August 25, 1929 (Engelhardt) ; 

 West Point, N. Y., September 11, 1926 (Col. Robinson). Hy. Edwards 

 confused this species with Syuanthcdon asiliforuiis Rottemburg from 

 Europe, based on specimens from Walpole, Winchester, and Cambridge, 

 Mass., in the collection of the Boston Society of Natural History. 

 5*. asiliformis is a borer in oak. 



THAMNOSPHECIA ARCTICA (Beutenmuller) 



Scsia arctica Beutenmuller, Can. Ent., vol. 32, p. 208, 1900; Mem. Amer. Mus. 



Nat. Hist., vol. 1, pt. 6, p. 283, 1901. 

 Synanthedon arctica McDunnough, Check list of the Lepidoptera of Canada and the 



United States of America, pt. 2, No. 8699, 1939. 



Male. — Antennae, palpi, head, and thorax entirely black. Abdomen 

 black, segments 2 and 4 narrowly banded with white posteriorly ; anal 

 tuft black. Legs black, hind tarsi whitish. Forewing transparent, borders 

 and discal mark very broad, black; underside shaded a golden yellow 

 basally. Hindwing transparent with a narrow black margin. 



Expanse: Male 20 mm. 



Distribution. — Kodiak, Alaska. 



