58 MISCELLANEOUS STUDIES 



15. Cornicles dusky for practically their entire length ............................................ 20 



Cornicles with less than apical one-half dusky .................................................. 16 



16. Cornicles considerably longer than III, with apical portion curved outward. 



About a dozen, medium-sized sensoria in a straight line along basal two- 

 thirds of III (fig. 131) .................................................. californicum (Clarke) 



Cornicles not considerably longer than III ........................................................ 17 



17. Cornicles and VI spur subequal, the former fairly long, slightly curved 



outward and Rightly swollen before the tip (fig. 128) ........ Stanley! Wilson 



Cornicles considerably shorter than VI spur, and not swollen before the tip 18 



18. Secondary sensoria in a fairly straight line on III. Body not pulverulent 19 



Body covered with a slight pulverulence. Ill with about 30 fairly large- 



sized sensoria, more or less scattered along the entire length (fig. 143). 



albifrons Essig 



19. Cornicles about half the length of VI spur and considerably shorter than III, 



the latter with about 20 to 30 secondary sensoria .................. pteridis Wilson 



Cornicles about two-thirds as long as VI spur and slightly shorter than III, 



the latter with about 15 sensoria (fig. 133) ................ cucurbitae (Thomas) 



20. Ground or basal color of abdomen green ............................................................ 21 



Ground or basal color of abdomen red, brown, or black .................................... 24 



21. Cornicles green, sometimes dusky at apex ........................ solanifolii (Ashmead) 



Cornicles black ........................................................................................................ 22 



22. Ill with a small number (9-15) of secondary sensoria on basal one-half 



(fig. 135) ; longer than VI spur ........................................ granarium (Kirbyj 



Ill with some 30 or more sensoria scattered along its entire length (figs. 151, 



159); subequal to or shorter than VI spur ......... . ........................................ 23 



23. Cornicles and III subequal. Tibiae with apices only dusky ........ rosae (Linn.) 



Cornicles longer than III. Tibiae dusky throughout. 



rudbeckiae (Fitch) n.var. madia 



24. Cauda pale ................................................................................................................ 25 



Cauda dusky ............................................................................................................ 27 



25. Ill and VI spur subequal ................... : ................................................ rosae (Linn.) 



Ill shorter than VI spur .............................................. . ....................................... 26 



26. Cauda about one-half as long as cornicles, the latter shorter than IV. 



chrysanthemi (Oestlund) 



Cauda slightly more than one-half as long as cornicles, the latter equal to or 



longer than IV ...................................................................... rudbeckiae (Fitch) 



27. Ill and VI spur subequal ...................................................................................... 28 



Ill longer than VI spur .................................................................. taraxici (Kalt.) 



28. Body yellowish-brown in color; legs same except tarsi and tips of tibiae and 



femora which are dusky to black ...................................... valerianae (Clarke) 



Body dark reddish-brown to black in color; legs dusky throughout. 



ambrosiae (Thomas) 



Apterous viviparous 

 1. Cornicles clavate on one side, somewhat as in Elwpalosiplium. 



tulipae (Monell) 

 Cornicles not so, being cylindrical or subcylindrical .......................................... 2 



10 Only the species of which there are specimens available to the author, or of 

 which there are adequate descriptions, are included in this key. The species rep- 

 resented in the author's collection are marked with an asterisk (*). The author 

 recognizes the great difficulty in separating the apterae of various species, par- 

 ticularly in this genus, and offers this key merely as a slight aid toward the recog- 

 nition of the better known species. 



