types and floral regions that it is, in the writer's opinion, 

 impossible to limit any so-called life zones. 



Dr. Transeau has shown that eastern North America 

 is occupied by four great forest centers: (1) the North- 

 eastern Conifer forest, centering in the St. Lawrence basin, 

 (2) the Deciduous forest, centering in the lower Ohio basin 

 and Piedmont plateau, (3) the Southeastern Conifer forest, 

 centering in the south Atlantic and Gulf coastal plain, and 

 (4) the Insular Tropical forest of the southern part of the 

 Florida peninsula, centering in the West Indies. 



Each of these large formations is made up of many 

 societies or associations. Although we find insects to be 

 to a great extent rather independent of minor differences 

 in climate, we find a large part of them definitely linked 

 with certain plant associations. And as the plant ecologi- 

 cal succession progresses, we find a parallel succession 

 taking place among the insects. 



Certain of the more important associations are here 

 taken up briefly with a discussion of the Homoptera that 

 are more or less typical of them. 



DECIDUOUS MESOPHYTIC WOODS ASSOCIATION 



A large area of the Southern States is covered by mixed 

 deciduous woods. The most abundant trees in the hills 

 are the short-leaf pine (Pinus echinata) and the old field 

 pine (P. taeda) and mixed with these are various species 

 of oaks, as the black-jack (Quercus nigra), post oak (Q. 

 stellata), Spanish Oak (Q. falcata) and scarlet oak (Q. 

 velutina), the dogwood and hickory. Beneath the trees 

 are many shrubs and the slopes are covered with grasses. 



The various species of oaks support a very numerous 

 insect fauna among which are such Fulgoridae as Thionia 

 bullata, Bothriocera tinealis, Cedusa vulgaris, and most of 

 the species of Otiocerus. Ormenis pruinosa, septentrionalis 

 and venusta breed on oak, hickory, sweet gum and many 

 shrubs and vines. The only known host plant of Cyarda 

 melichari is young hickory and this is also the favorite food 

 plant of Cedusa obscura and vulgaris. Poblicia fuliginosa 

 breeds on the sumach. Amalopata mcateei and Cenchrea 

 uhleri have been taken by the writer on Iron wood (Carpinus 



11 



