No. 34-] HEMIPTERA OF CONNECTICUT: APHIDIDAE. 285 



Forms living upon the foliage of trees. Small lamellate or hairy 

 dimorphic forms developed in summer ; bodies usually elongate. 



Key to Species. 



1. Segment iii of antennae with 4 to 9 sensoria in a more or less even 



row 2 



Segment iii of antennae with 16-24 sensoria somewhat irregularly 

 placed on the basal three-quarters of the segment ...... .americanus 



2. Unguis of segment vi of antenna less than three times as long as 



base . negundinis 



Unguis of segment vi of antenna much more than three times as 

 long as base, often more than four times as long ......... .lyropicta 



Key to Dimorphs of Species. 



1. Antennae considerably shorter than body; base of distal segment 



one-third as long as unguis 2 



Antennae nearly as long as the body ; base of distal segment about 

 one-quarter as long as unguis americanus 



2. Base of distal segment one-third to one-half as long as unguis 



negundinis 

 Base of distal segment fully as long as unguis japonicus* 



P. americanus Baker. Chaitophorus americanus Baker. (Fig. 

 28, 16.) 



Jour. Econ. Ent, 10, 428, 1917. 



On sugar maple. 



Brookfield Center, 10 May, 1913 (C. Holder). 

 P. lyropicta (Kessler). Chaitophorus lyropictus Kessler. 



Nova Acta, Deutsch. Akad. Nat, li, 171, 1886. 



On Norway maple. 



Mcriden, 26 June, 1912 (Louis A. Gudebrod). 

 P. negundinis (Thomas). Chaitophorus negundinis Thomas. 



111. St. Lab. Nat. Hist, Bull. 2, 10, 1877. 



Sipha Passerini. 



Cornicles truncate, short, almost mere rings. Antennae of five 

 segments armed with large circular sensoria. Body form flat, 

 entire insect often covered with long, stout hairs. Fore wing with 

 the media twice branched ; hind wing with both media and cubitus 

 present. Cauda knobbed. Anal plate rounded. Only one species 

 recorded from New England. 

 S. glyceriae (Kaltenbach). Aphis glyceriae Kaltenbach. 



Mon. der Pflanz. 113, 1883. 



Subtribe Drepanosiphina. 



Cornicles present, usually prominently developed; cauda as a 

 rule knobbed and the anal plate entire, slightly indented or bilobed. 

 Oviparous female with a long drawn-out ovipositor. 



* This species is known only from the dimorph and it has been taken only 

 in Pennsylvania. 



