164 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



regions that the many curious and grotesque forms, which are so 

 often figured to illustrate extreme pronotal development, are 

 most abundant, and that the number of genera and species reach 

 the maximum. In North America the family is best represented 

 in Mexico where the characteristic bizarre forms are plentiful. 

 Southern United States shows fewer species and these lose their 

 grotesque appearance as they spread northward. Northern United 

 States continues to show the thinning-out of the forms as th( 

 climate becomes colder, and the native species are on the whole 

 smaller and of less striking development. Of over three hundred 

 genera established in the family, only forty are found in North 

 America and of these a number are represented by a single species 

 only. 



As is to be expected, therefore, the New England States are 

 near the northern limits of membracid fauna (only a few species 

 are found in Canada) and the small number of species represented 

 makes the determination of forms a comparatively easy task. 

 Approximately one hundred species, representing about twenty 

 genera,, are recorded from this region. 



Habitat and Habits. 



The Membracidae are primarily tree and shrub inhabiting 

 insects ; a few species may be taken in general sweeping but the 

 great majority are to be found on the lower branches of trees 

 (seldom more than twenty feet from the ground) and particularly 

 on small saplings, bushes and shrubs. They are sun-loving 

 creatures and are found oftenest on plants growing in open fields, 

 along roadsides, and at the edges of timber. They are seldom 

 seen in shady woods. 



The adults of many species have the habit of arranging them- 

 selves in rows on the branches or trunk, generally with the head 

 pointing toward the base of the branch, or pointing downward if 

 on the trunk. Nymphs are usually found tightly flattened in 

 crevices of the bark or pressed closely in the axil of a leaf or the 

 crotch of a twig. Both adults and nymphs show a considerable 

 amount of protective resemblance, particularly those species which 

 are provided with dorsal horns or crests. 



Some species are decidedly gregarious and congregate not only 

 as individuals of the same species but also with other species (e.g., 

 Thelia bimaculata and Vanduzea arquata on the locust), others 

 live together as individuals of a species but are seldom found with 

 other species (e.g., Enchenopa binotata on the butternut), others 

 spend their nymphal lives as a family group but separate on reach- 

 ing maturity (Ceresa bubalus on sweet clover), while others are 

 usually solitary both as nymphs and adults (most species of the 

 genera Telamona, Smilia and Carynota). There is reason to 



