14 INSECUTOR INSCITI^ MENSTRUUS 



fectly smooth, without patches of accessory spines. Segment 

 10 sHghtly longer than basal width, acutely rounded at apex, 

 divided above. 



Measurements of holotype : Length 1.09 mm. ; head, length 

 0.130 mm., width 0.128 mm. ; prothorax, length 0.212 mm., 

 width 0.292 mm. ; pterothorax, width 0.366 mm. ; fore wing, 

 length 0.732 mm., width at base 0.075 mm., at middle 0.051 

 mm. ; abdomen, width 0.360 mm. 



Antennal segments 1 2 3 4 5 6 7 8 



Length (\i) 32 31 32 32 24 35 13 12 



Width (n) 50 45 24 27 21 18 7 4 



Total length of antenna, 0.211 mm. 



Described from 210 females, as follows : Glendale and Phoe- 

 nix, Arizona, October 4 and 6, 1913, H. M. Russell, 200 fe- 

 males on sugar cane; Brownsville, Texas, December 8, 1910, 

 C. A. Hart, 1 female in sweepings ; Mission, Texas, June 26 

 and 30, 1914, J. W. Bailey, 3 females; Dallas, Texas, August 

 26, 1905, and August 8, 1906, W. A. Hooker, 2 females in 

 laboratory ; New Orleans, Louisiana, December 1, 1914, C. B. 

 Williams, 4 females from privet and bamboo. 



Type locality. — Region of Glendale and Phoenix, Arizona. 



This, one of the dominant species of Chirothrips in southern 

 United States, is commonly labeled C. ohesus Hinds in collec- 

 tions, so close is the superficial resemblance of the two. It may 

 be separated without difficulty from that species, however, by 

 the greater number of spines on the vertex, the longer pro- 

 thorax, and the much larger size. 



The following is from Mr. Russell's notes : "I found this 

 species first in the fall of 1913, feeding on sweet corn, Johnson 

 grass, and sugar cane. On the first two food plants it occurred 

 in small numbers, while on the sugar cane it was very abun- 

 dant, those collected representing only about twenty minutes' 

 work. Undoubtedly the 10 acres of cane were infested with 

 millions. Each unfolded growing leaf-bud contained numbers 

 of these minute creatures. At that time the growing season 

 of the cane was about over, so that the species had had the 

 entire season to increase in. They were feeding on the tender, 

 moist leaves. When exposed to the light, they rapidly crawled 



