772 



Pomona Coixege Journal of Entomology 



5. 



First segment (if tlie tarsus equal to one-half of the second. eulnchnus 



First segment ut tlie tarsus not nearly equal to half of the second. 3 



Winged females usually present, tarsi of all legs two-segmented. 4 



Winged females never found (as yet), tarsi of hind legs with but 



one segment, other two pairs of legs with two segments. trama 



Wings carried pentwise (normally), rostrum scarcely reaching be- 

 yond middle of the abdomen. 5 

 Wings carried horizontally (folded flat on the back), rostrum of 



apterous forms much longer than the body. slmnaphis 



Stigma not reaching to the wiiig tip, not exceptionally long. 6 



Stigma exceptionally long, and reaching around the tip of the 



wing. longistigina 



6. Abdomen witli a horn-like tuberch^ nn the median dorsum between 



the cornicles. tuherolachnus 



Abdomen without the liorn-like tuliercle on the median dorsum. 7 



7. Bases of the first and second diseoidal veins usually close together, 



third diseoidal often very faint, wings but slightly or rarely 

 clouded. hchnns 



Bases of first and second discoidals farther apart than in "Lach- 



nus," third diseoidal plain, wings often darkly clouded. pfcrochlorufi 



8. Tarsi with first segment half as long as the second. es.iigella 

 Many of these genera are represented by but one species which fonns the 



type, and but few are found in California. It is, therefore, unnecessary to give 

 but the synonomy and type species of the most of them, while of those found in 

 this state I shall also give a key to the species. (The type species and generic 

 synonymy is strictlv after Wilson.") 



EULACHNUS Del Guercio 

 Type Lachnus agilis Kalt. 



TRAMA Heyden 

 Type T. troglodytes ITeyd. 



STOMAPHIS Walkcr 

 Type Aphis quercus Linn. 



LONGISTIGMA Wilson 

 Syn. Davisia I'd (luercio 

 Tyi)C Aphis caryae Harris 



Tuberolachnus Murdwilkd 



? Syn. Schizolachnus Mord. 



Type Lachnus viminalis I-'onsc. 



T. vimiiialis (Fonse.) Mord. On .SV///.r fluriatilis Null, in Placer County 



by WuL Davidsrn. P. C. Jr. Ent., Ill, p. 398, 1911. On S. macrostachya Nutt. 



and S. laevigata liebb. in Ventura County by writer. (See in Litt.). 



