June-0ct.,i92i Bulletin of the Brooklyn Entomological Society 81 



willow at Cranberry Lake in the Adirondacks by Prof. Carl J. 

 Drake in July, 191 9. Types in the author's collection. 



Agrees with T. fuscicornis Hood in the unarmed fore tarsi of 

 the female and the pedicellate 8th antennal segment, but differs 

 in the length and color of the third segment and in the 7th not 

 being noticeably shorter than the 8th. 



Key to the Species of Trichothrips of North America. 



1 (6) Prominent spines on body with blunt or dilated tips ; most 



forms very dark brown or nearly black (except T. angusti- 

 ceps), usually with short wings (except T. longitubus). 



2 (3) Each fore tarsus armed with a tooth; antennae about 1.7 



times as long as head; total body length about 1.5 mm. 



T. angusticeps Hood ('08). 



3(2) Fore tarsi not armed; antennae about twice as long as 

 head. 



4 (5) Wings fully developed; body length about 1.8 mm.; tibiae, 



tarsi, and intermediate segments of the antennae bright 

 lemon yellow ; tube fully as long as the head. 



T. longitubus Hood ('08). 



5 (4) Wings short; body length about 1.2; whole antenna clear 



yellow ; tube about half as long as the head. 



T. brevitubus Watson ('18). 



6(1) Prominent spines on body acute ; antennae about twice as 

 long as head. 



7 (10) Individuals small, about i mm. in length, without ocehi or 



wings. 



8 (9) Eyes reduced, lateral profile showing but three facets ; first 



segment about half as long as the second. 



T. smithii Hood ( 09) . 



9 (8) Eyes small, but normal; first antennal segment nearly as 



lono- as second T. flavicauda Morgan ('13)- 



10(7) Individuals rather large, 1.5 mm. or more, wings fully 

 developed or brachypterous. 



11 (22) Each fore tarus armed with a tooth. 



12 (13) Antennae 1.75 times as long as head; tube .7 as long as 



head ; total length about 2 mm., fore tarsi with a short, 

 stout tooth T. ambitus Hinds ('02). 



13 (12) Antenna slightly more than twice as long as the head; 



tube slightly shorter than head. 



