Pomona College Journal of Entomology 715 



Spur of article VI more than five times as long as the base, and cor- 

 nicles longer tlian the base. Chaitophorus 



4. Spur of article VI more than four times as long as the base, cauda 



constricted at the base. 5 



Spur of article VI not four times as long as the base, and the Cauda not 



constricted at the base. MicreUa 



5. Stipe of Cauda well developed and on a conical base, anal plate con- 



stricted in the middle. Eichochaitophorus 



Stipe of Cauda obsolete or not well developed and on a quadrangular 



base, anal plate well rounded. Arctaphis 



6. Antenna? about half the length of the bodj' and the s))ur of article VI 



considerably longer than the base. 7 



Antennae nearly as long as the body and the spur of article VI sliorter 



or scarcely longer than the base. Symdohius 



7. Cornicles absent, body with lateral tubercles. Fullawaya 

 Cornicles present, lateral body tubercles wanting. Thomasia 



8. Antennae shorter than the body, cornicles very short and tapering with 



flanged mouth. Sipha 



KEYS TO CALIFORNIA SPECIES 



CHAITOPHORUS Koch. 

 Type Aphis aceris Linn. 

 No California representative in this State to date. 



MICRELLA n, ^en. 

 Type M. monelli n. sp. 

 One species described. 



M. monelli n. sp. On Salix lasiolepis Benth. and S. laevigatae Bebb., at 

 Oxnard and Santa Paula, Cal. 



EICHOCHAITOPHORUS n. gen. 

 Type E. populifolii n. sp. 

 One species as herein described. 

 E. populifolii n. sp. On Populus trichocarpa T. & G., Santa Paula, Cal. 



ARCTAPHIS Walker 

 Type A. populi Linn. 

 No California species reported. 



SYMDOBIUS Mordwilko 

 Type A. oblongus Heyden 

 1. Body small, nearly black, abdomen of apterous female with lateral 



body tubercles. macrostachyae 



Body large, never black, abdomen of apterous female without lateral 



tubercles. salicicorticis 



S. macrostachyae n. sp. On Salix macrostachya Nutt., Santa Paula, Cal. 

 S. salicicorticis n. sp. On base and roots of Salix laevigata Bebb., near Santa 

 Paula, Cal. 



