— 186— 



To both the student and philosopher there is no more interesting 

 family to stud}' than the Aphididce, and connected with their life histories 

 are many scientific problems, that yet remain unsolved. 



The females of many of the species are viviparous, although some 

 of these are now known to be merely the dimorphic or seasonable variety 

 of an oviparous form, and some of these /;'6»i5<;?(5/i' change tlieir food-plant 

 and habitat as often as there are seasons in the year. 



The eggs of most of the Aphididce are long oval, but in some of the 

 lower forms they are more or less spherical. Many of the species live 

 in galls, others Cdver themselves with a wooly or flocculent secretion, 

 while a few seciete a waxy covering for themselves analogous to that 

 produced by the Coccids. 



The family may be divided into seven subfamilies, recognized by 

 the aid of the following table : 



TABLE OF THE SUBFAMILIES. 



A- Honey tubes always diVtincI, often f[uite long. 



Front wings with a double foiketl cubitus ; hind wings with two oblique veins ; 



antennas y-jointed SUBFAMILY I. APHIDINiE 



B — Honey tubes very short, tuberculifoim or subobsolete. 



Front wings with a double foiked cubitus (except in Ainycia Koch) ; hind wings 

 v\'itli two iiblique veins. 



Antennae y-jnnited, the 7th joint cetaceous, not rudimentary 



SuiiFA.MiLv II. CALLIPTERINiE 



Antenna.' 6-jointed, usually with a spur or ruiliuuntaiy 7th joint. 



Sl.bfamii.v III. LACHNIN^ 

 C--N0 honey tubes. 



Front wings with cidiilus once forked ; hind wings with one or two oblique 

 veins. 



Antenna; 5- or 6-jouited Subfamily IV. SCHIZONEURINiE 



Front wings with culjitus not forked ; h;nd wings with one or twoobliipie veins. 



Anteniue 5- or 6-jouited Subfamily V. PEMPHIGINiE 



P"ront wings with only three veins. 



Antenna; 5-jointed ; hind wing with a subcostal nerve and an oblique vein. . 



Subfamily VI. CHERMESIN.(E 

 Antenna; 3-jointed ; hind wing with a subcostal nerve and no oblique vein. . . 



Subfamily VII. PHYLLOXERIN.<E 



Subfamily I. APHIDIN.*^. 

 TABLE OF GENERA. 



1 Antennaf not on Irontal tubercles 4 



Antenna; on frontal tubercles. 



Antennse not approximate at base ; frons not grooved, flat or convex 2 



Antennre approximate at base ; irons grooved G. i. Siphonophora Koch 



2 First antennal joint with a tooth on the inside G. 2. Phorodon Pass. 



First antennal joint without a tooth on the inside. 



