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CIRCULAR 2 41, U. S. DEPARTMENT OF AGRICULTURE 



to constitute good characters for recognition. The face is usually 

 marked with numerous black bars; sometimes it is entirely black or 

 has only a few light streaks on the lower portion. The nymphs of 

 this species appear early in the summer, and the adults are usually 

 to be found in numbers by the 1st of July. These adults deposit 

 eggs from which nymphs develop during July and August, and 

 adults appear in September and are to be found on into October and 

 November, and in localities farther south may be taken in numbers 

 as late as November and early December. In fact, they seem to 

 remain active until severe cold weather forces them into inactivity. 



MEANS OF CONTEOL 



The methods of control for this species may be based directly 

 upon the migratory habits of the species and especially upon the 

 fact that it develops so largely in the field grasses which are either 

 worthless or noxious in character. In many places the mere elimi- 

 nation of foxtails and panics which grow along the borders or in 



Figure 5. — The black-faced leaf hopper (Thamnotettix nigri- 

 frons) : a, Adult, X 10 ; b, vertex and pronotum ; c, face; d, 

 female genitalia ; e, male genitalia ; f, wing 



neglected cornfields would greatly reduce the numbers of this pest, 

 and in some instances it would be entirely practicable to burn the 

 borders of fields, where such grasses are beginning to wither, in 

 time to kill the hoppers which ma}^ occur there. In the Southern 

 States, especially where fields are often interspersed with strips of 

 uncultivated ground, the burning or even close mowing of such 

 strips would doubtless be of considerable service in preventing injury 

 to fall wheat and oats. Additional knowledge concerning the actual 

 method of deposition of eggs may add to the possible measures for 

 control. 



THE STRIATE LEAF HOPPER 



The striate leaf hopper, Deltocephalus striatus L., has been dis- 

 cussed under the names debilis, melsheimeri, and affinis in earlier 

 articles, but it was noticed as an economic species in 1890. It was an 

 extremely abundant and apparently destructive species in Iowa dur- 

 ing a number of years when it was observed in that State. It occurs 

 in greatest abundance in bluegrass, in lawns, and upon pastures or 

 meadows, showing a distinct preference for open and sunny situa- 

 tions rather than shaded locations. 



