No. 34-1 HEMIPTERA OF CONNECTICUT: APHIDIDAE. 319 



Trifidaphis Del Guercio. 



Stem mother unknown. Apterous viviparous females with five- 

 jointed antennae. Joint ii longer than i, subequal to iii. Perma- 

 nent sensoria of all generations without fringe of celia. 



Antennae of alate viviparous females six-jointed. Abnormal 

 specimens with five joints. Joints ii longer than i, subequal to iv. 

 Sensoria oval to subcircular. Fore wing with M simple. Hind 

 wing with both media and cubitus present. Their bases united. 

 Cornicles wanting. Sexuals unknown. Species living on roots 

 of grasses and herbs. This genus contains a single species. 

 T. radicicola Essig. 



Pom. Jour. Ent, i, 8, 1909. 



Tullgrenia van der Goot. 



This genus is very similar to Trifidaphis, yet it differs from it 

 sufficiently to warrant their separation for the present at least. 



Stem mother unknown. Apterous viviparous females with six- 

 jointed antennae. Joint ii longer than i but shorter than iii. Per- 

 manent sensoria without fringe of celia. Cornicles and rudi- 

 mentary gonopophyses wanting. Antennae of alate viviparous 

 females six-jointed. Joint ii longer than i, subequal to iv. Sen- 

 soria oval to subcircular. Fore wing with M simple. Hind wing 

 with both media and cubitus present. Their bases remote. 

 Cornicles wanting. Sexuals small, beakless, females laying but 

 one Ggg. 

 T. phaseoli Passerini. 



Gli, Afidi., 39, i860. 



This is the only species in the genus and feeds upon the roots of 

 beans. 



Tribe PEMPHIGINI. 



The species of this tribe live exposed on the twigs of the host, 

 within curled leaves or pseudo galls, or within true galls produced 

 upon the leaves or young wood of the winter host. Summer 

 generations produced on roots of trees, herbs and grasses. At 

 least one species produces aerial summer generations on Ciciita 

 occidentalis. 



Stem mother with four- or five-jointed antennae. Young of 

 stem mother winged or apterous. Wax production highly devel- 

 oped. Wax pore plates composed of many several-sided facets of 

 equal size, closely arranged. Cornicles absent or present. 

 Reduced to slightly raised rings. Antennae of alate form six- 

 jointed. Sexuals small, beakless, female laying but one egg. 



Key to Genera. 



I. M of fore wing once forked 2 



M of fore wing simple 3 



