194 IOWA ACADEMY OF SCIENCES. 



Female: Vertex nearly twice as long as broad, slightly more than twice 

 as long on the middle as next the eye; light yellowish with fine brownish 

 irrorations; a median light line, broadest on tip fading out on the disk, on 

 either side of this a curved line extending back from the edge on to the 

 disk. Front with the usual dark V under the vertex, remainder of the ver- 

 tex and the clypeus light lemon-yellow; loree and genas slightly, finely 

 maculate with brown: pronotum short, fulvous brownish, lateral margins 

 long, posterior angles obscure, emarginate; between them traces of longi- 

 tudinal light lines; scutellum large, light yellow, tip darker. Elytra light 

 with fulvous brown irrorations; apical and costal veinlets dark, terminal 

 spots in cells and costal margin whitish-hyaline; tip slightly clouded with 

 dark fuscous. 



Male: Smaller and shorter, the vertex is only about one and one-half 

 times as long as broad and the terminal cells are clouded with fuscous 



Genitalia: Ultimate segment of the female long, rounding behind nar- 

 rowly notched in the middle, slightly lobately produced either side of the 

 notch; pygofere light yellow, three times as long as width at base. Male 

 valve large, roundingly pointed, dark at the base; plates roundingly pointed, 

 twice the length of the valve, maculate. 



Larvae: Similar in form to those of acutus but smaller; they are about 

 three and one-half millimeters long by one and one-half wide in the middle 

 when full-grown. Widest just before the middle, gradually and regularly 

 narrowing to an acute point at either end Tuere is a broad lemon-yellow 

 dorsal stripe, narrow, wedge-shaped on the vertex with indefinite margin; 

 broad, with definite parallel margins on thu thorax, constricted slightly on 

 the base and again before the extremity of the abdomen, bordered on either 

 side by a dark fuscous marginal stripe, irreguLti" in width, narrow before 

 the eyes, meeting under the vertex. Numerous fine white maculations of 

 various sizes dot this stripe. 



The larvae are readily distinguished from those of acutus by 

 the absence of red in the dorsal stripe, and from those of fron- 

 talis by the much more elongate form. 



The larvse were first observed early in June, when they were 

 nearly full grown, and by the third week had disappeared. The 

 adults appeared very thickly by the middle of June and contin- 

 ued in decreasing numbers until after the middle of July. The 

 second brood of larvae appeared by the last of July and con- 

 tinued in large numbers up to the middle of August. The 

 second brood of adults appeared the second week in August, con- 

 tinuing through September. 



This is the smallest known species of the genus, and the most 

 abundant at Ames, occurring everywhere that wild grasses are 

 found. Specimens have also been received from Kansas, 

 Nebraska and Arizona, bhowing it to have a wide distribution 

 throughout the prairie and plain region at least. 



By a process of elimination of grasses not occurring in places 

 where the larvte were found abundantly its list of host plants 



