64 IOWA ACADEMY OF SCIENCES. 



NOTES ON THE ACOCEPHALINA (Homoptera-Jassidae). 



E. D. BALL. 



Strongylocephalus agrestis fall. 



Tettigonia mixta Say. 



This widely distributed European species has been found in 

 New York, Michigan and Iowa; and this season it was found 

 abundantly in Colorado, as far west as the foot-hills, indicating 

 a very general distribution east of the Rockies, at least. 



It occurs only in low places, where the vegetation is rank, 

 and is found down underneath the grass and weeds crawling 

 through the rubbish at the roots of the various plants. The 

 larvae appear in the fall, pass the winter about half grown, 

 from which adults emerge the next summer. It is appar- 

 antly only single brooded, but the adult females often live over 

 winter and are found nearly the whole year around, while on 

 the other hand the male is rarely seen. 



Say's description of T. mixta, agrees very well with the dark 

 females, the length "less than three-tenths inch," and "the 

 white stripe on the lateral margin of the pronotum " agreeing 

 especially well, while the females of the genus Acocephalus 

 which have been called mixta are less than two-tenths of an 

 inch, and the males much smaller. 



ACOCEPHALUS GERM. 



In this genus the sexes differ widely in size and color, 

 the females are all very much alike — dirty, straw-yellow, 

 heavily irrorate with fuscous, and are difficult of determination, 

 except as they are found in company with the males. The 

 males are much smaller than the females, and are strongly and 

 variously colored. The genitalia are of little value, and accu- 

 rate determinations are based on the color pattern of the males. 



Three species, all widely distributed in Europe, are now 

 known for the eastern United States. The males may be 

 separated as follows: 



