A SYNOPSIS OF THE APHIDIDAE 11 



The latter subfamily has been considered by the author as Phyllox- 

 erinae Dreyfus; the former as two subfamilies, Aphidinae Buckton 

 and Pemphiginae Mordwilko. Mordwilko gives the following char- 

 acters for these two subfamilies : 



Subfamily Pemphiginae Mordw. : Antennae of the alate forms five- or six- 

 segmented, the third bearing a specifically definite number of transverse or arch- 

 like sensoria; short, usually not longer than the head and thorax. The apterous 

 parthenogenetic females have four- to six-segmented antennae, but these are 

 sometimes reduced to three or even to two segments. The fore wings of the 

 alate forms have four transverse veins, of which the third or cubital vein [third 

 discoidal] is either simple or once-branched. The hind wings have one or two 

 transverse veins. The cornicles are either entirely absent or very slightly devel- 

 oped, and in the latter case may not be present in all the forms of one species. 



Subfamily Aphidinae Buckton: Antennae always six-segmented, except in the 

 stem mother of some species, and in the genus Sipha Passerini. [This genus is 

 not represented in California. In Essigella Del Guercio, Cerosipha Del Guercio, 

 and Trifidaphis Del Guercio, three Californian genera described since the publi- 

 cation of Mordwilko 's paper, the antennae are but five-segmented.] The last 

 antennal segment often ends in a long thread-like filament which may be longer 

 than the segment. Antennae with a long filament are mostly from half the 

 length of the body to longer than the body. The antennal filament is character- 

 istic only for this subfamily; some genera of the groups Lachnina and Callipterina 

 have a very short filament, and the antennae are not longer than the head and 

 thorax. The sensoria are small and are shaped like dots, circles, or transverse 

 holes, but never archlike or half-rings. Segment 3 bears the largest number, 

 especially in the alate forms. The cubitus [third discoidal] of the fore wings is 

 usually twice-branched although there are some exceptions, as Toxoptera Koch. 

 Most species have long cylindrical cornicles which are often clavate in the middle. 

 Sometimes they may be greatly reduced or poorly developed, and, as in Lachnina 

 and Callipterina, they may be replaced by cupola-shaped elevations. A cauda 

 is usually present, being conicle, ensiform, or globular, although in Lachnina it is 

 not evident. The sexual forms have beaks, and become quite large. 



Subfamily Aphidinae Buckton 



Buckton, Mono, British Aphides, 1883. 



This subfamily is divided into three groups, following Carl Borner 

 (Sorauer, Paul, Handbuch der Pflanzenkrankheiten, vol. 3, p. 664, 

 1913). Borner considers the family Aphididae as a superfamily, and 

 divides it into four families ; so this subfamily Aphidinae he considers 

 a family, and the various groups as subfamilies. Below is a trans- 

 lation of his key : 



1. Claws with spatula-like or leaf -shaped empodial hairs (fig. 1). Cornicles vari- 

 ously formed, bare. Pubescence of larvae as in Aphidina. The majority 

 of the species live free and monophagous on trees, only seldom on herbaceous 



plants, and never migrate collectively Group Callipterina 



Claws with simple empodial hairs (fig. 2), often hard to see 2 



