28 INSECUTOR INSClTIyE) MENSTRUUS 



posed as follows : Five along costa, the basal one smallest ; 

 three on median vein, all in distal half ; three along anterior 

 margin of scale, the distal one much the longest ; and one near 

 apex of wing, on anal margin. Legs straw yellow, darker at 

 sides of femora and tibiae. 



Abdomen rather short and broad ; tenth segment not sulcate 

 above ; bristles dark brown, stout and conspicuous ; segments 

 3-6 each with three pairs of prominent dark brown bristles 

 disposed in a transverse row across middle of notum ; 7 and 

 8 with two pairs of similar bristles. 



Measurements of holotype : Length 0.97 mm. ; head, length 

 along median dorsal line 0.096 mm., width 0.154 mm. ; pro- 

 thorax, length 0.144 mm., width 0.196 mm., pterothorax, width 

 0.222 mm. ; abdomen, width 0.306 mm. Antennal segments : 

 1, 24^1 ; 2, 38^; 3, 55^; 4, 46^; 5, 41ja; 6, 52^i; 7, 24[x; total 

 length of antenna, 0.280 mm. ; width at segment 4, 0.018 mm. 



Male (forma brachyptera). — Length about 0.66 mm. Color 

 paler than in female. Head proportionately longer than in 

 female, about 1.4 times as long as wide, and about 0.8 as long 

 as prothorax. 



Measurements of allotype : Length, 0.66 mm. ; head, length 

 along median dorsal line 0.096 mm., width 0.132 mm. ; pro- 

 thorax, length 0.108 mm., width 0.168 mm.; pterothorax, 

 width 0.186 mm. ; abdomen, width 0.234 mm. Antennal seg- 

 ments: 1, 24^1 ; 2, 30[x; 3, 42fx; 4, 37^; 5, 35pi; 6, 45n; 7, 19^; 

 total length of antenna, 0.32 mm. ; width at segment 4, 0.015 

 mm. 



Described from 49 females and 2 males, taken by Mr. J. R. 

 Malloch and the writer near Alexandria, Virginia, May 12, 

 1913, on the leaves of young plants of Anthemis cotula L. 



The short wings, broad head, long prothorax, and the color 

 make this species easily separable from its North American 

 allies, though it is to some extent suggestive of Thrips lac- 

 tuccs Beach. It is perhaps more closely related to the European 

 nigropilosus, but differs from that species in the form and 

 armature of the fore wings and in the coloration of the an- 

 tennae. 



