AMERICAN HYMENOPTERA. 365 



less distinctly), second and a band interrupted in middle, on the third, 

 fourth, fifth, sixth, seventh and eighth segments of abdomen, a dot at 

 apex, and generally the cornus and the enclosed space at its base yel- 

 low ; venter yellow or yellow banded ; remainder of spine and the valves 

 of oviduct dark ferruginous; ovipositor black ; cornus short, serrate 

 acuminate ; ovipositor as long as abdomen and cornus combined ; legs 

 reddish yellow ; coxa3 and trochanters black ; femora above and at base 

 blackish ; all the tai-si flattened, the posterior pair most, the first pos- 

 terior tarsal joint longer than tibiae, concave within ; wings sub-opaque, 

 varying from black to yellowish, most obscure about the base and upper 

 margin ; second brachial cell without additional cross line. 



% . — The colors of the male are obscure, varying between ferrugi- 

 nous and black, the yellow spots and bands wanting ; antennae 14- 

 jointed, color as in female ; thorax obscure , sometimes wholly black; 

 abdomen polished, blackish, with bands more or less ferruginous on the 

 fourth, fifth, sixth, seventh and eighth segments and the cornus (abdo- 

 men sometimes wholly blatjk with a fine punctuation and striation visi- 

 ble); cornus rather longer than with female, serrate, rough beneath; 

 legs pale ferruginous; coxae, trochanters, basal half of four anterior 

 femora, posterior femora, a line down anterior tibias, apical two-thirds 

 of four hinder tibifc and of first joint of their tarsi and the two next 

 joints of tarsi, black (the black is sometimes wanting below the femora), 

 first joint of posterior tarsi not so long as tibioe or as the remaining 

 tarsi taken together, the tibia? and tarsi much flattened and concave 

 within; wings less obscure, yellowish, nervures red yellow. 



Canada, Northern and Middle States, Missouri. 



The male does not look at all like the female. The larvae are like 

 those of Uroccnis. The eggs are deposited in several kinds of trees. 

 It is known to attack the pear, elm, sycamore and maple, but is not 

 often so common as to be injurious to more than isolated trees. It 

 seems probable also that it does not begin upon trees which are en- 

 tirely sound. 



Trcmcx obsolctics, Say, may possibly be the male of T. spriceus, but 

 it is almost precisely like a male of T. columba from New York. 



Dr. Harris states that the larvae are destroyed by Ehysaa atrata 

 aad R. lunator. 



This is much like the T. /usciconiis of Europe. ■ 



