192 Psyche [December 



late winters have occasioned correspondingly early appearance and 

 late persistence of the forms in the field. 



Such conditions seem undoubtedly to affect the eggs and the 

 nymphs, and may very logically be presumed to have an influence 

 also on the mating, oviposition and general activities of the 

 adults. 



Hosts. 



Robinia psetidacacia L. seems to be by far the most favored 

 if not the only host in this locality. Specimens of Vanduzea 

 arquata have been collected on willow, oak, elm and wild cherry 

 in localities where there were no locusts in the immediate vicinity 

 but as the Membracid under consideration flies well, its appearance 

 on these trees may have been accidental. No evidences of eggs 

 or nymphs have ever been found except on the locust, nor have 

 specimens ever been collected in the grass or weeds or by sweep- 

 ing, so that is seems evident that the entire life cycle of the insect 

 is usually spent on this one host. Van Duzee gives the locust as 

 the dominant host for Ohio and southward (Studies in North 

 American Membracidse, 103. 1). 



It may be of interest to note that, although Robinia viscosa 

 Vent, and Gleditsia triacanthus L. are well represented in the 

 local flora, they are never found as habitats for these Membracids. 



Enemies. 



This species of Membracidse seems to have few natural enemies. 

 The eggs are not infrequently parasitized but the writer has not 

 been able to rear the parasites and they have not been determined. 

 The parasitism does not seem to extend to the nymphs or the 

 adults and, although a large number of both have been dissected 

 with a view to ascertaining this fact, no parasitic larvae have 

 been found. This is rather remarkable in view of the fact that 

 the local forms of the genera Telamona and Thelia are commonly 

 parasitized. 



Birds feed on the nymphs but not to any great extent. A 

 chipping sparrow has been watched industriously searching for 

 the immature forms but neglecting the adults. The latter are 

 probably sufliciently protected from bird enemies by the hard 

 pronotum and sharp posterior process. A number of instances of 



