67 



stances. This has occasionally been found useful for the destruction 

 of the true army worm. One farmer in Mason county, who noticed 

 that the grass worms were extending their ravages rapidly from 

 the central area in which he first noticed them, believed that he de- 

 stroyed the brood and prevented further injury by plowing under 

 the infested area and rolling it heavily immediately thereafter. If 

 a disposition to migration, like that of the army worm, is apparent, 

 the march of the host may be arrested by measures wdiich have 

 been found more or less efficient in the case of the last named in- 

 sect ; that is, a furrow may be plowed across the line of their 

 march, when the worms collecting therein may be destroyed by 

 dragging a log along the furrow. If their appearance is easily de- 

 tected while they are still small, it might not be unprofitable to 

 destroy them with Paris green or other form of insect poison, but 

 in most instances it will doubtless be less expensive to resow the 

 ground than to attempt the somewhat doubtful remedies here pro- 

 posed. 



7. The Grain Leaf-Hoppers. 



Order Hemiptera. Family Jassid.t:. 



A great number of species of minute leaf-hoppers are found upon 

 growing grain, usually inflicting only insignificant or temporary 

 damage, even if their effect is finally appreciable ; but a few species 

 were found by us last summer abundant enough in fields of growing 

 wheat, in May and June, to constitute a menace to the crop where 

 the conditions were not otherwise entirely favorable to its growth. 

 Two of these, conflned to the cereal crops as far as our observations 

 show, were new to science ; while a third, wide spread, occurring in 

 many situations and upon a considerable variety of plants, is a 

 common species, described originally by Say under the name of 

 Jassus irroratus. 



The first two are closely allied to Jassus inimlcus, Say, described 

 in 1831,* the describer of that species adding the remark that it is 

 said to depredate, in the larva state, on the roots of wheat in Vir- 

 ginia. 



Cicaclula nigrifrons, n. s.t 

 (Plate v. Fig. 3.) 



A moderately slender, yellowish green species, with four black 

 points at the anterior margin of the vertex. The head is sublunate, 

 obtusely rounded in the middle, its antero-posterior diameter next 

 the eyes being about three-fourths its median diameter. Its color 

 is pale yellow, irregularly mottled with white, with an arc of four 

 irregular black points at its anterior margin, the outer of these just 



^ * Complete writings, Vol. II, p. 382. 



t Although this species differs by characters commonly esteemed generic from the 

 following and from any other genus known to me, yet in the present state of the generic 

 classification of our American Homoptera I have not thought it best to multiply descrip- 

 tions of genera, but content myself with indicating the distinctive characters in the 

 figures accompanying. 



