Pomona College Journal ok Entomology 



707 



/V;/i/)/iiirH.v populimoiiilis Rihy whs first r. jH.rt.d on tin- iinrrow-l<avc-d 

 ('ottoiiwood (Popiiliis liahamifrra I,, vnr. aiiguitifolia Torrt-v), but lias since been 

 found fcc(lin({ upon Populus Irirhorarpa T. «: (1. first by Ciillcttc in Jr. Kc. Ent. 

 II. p. .S/it), 1909, n»ar Portland. Orison. l)a\i(K()M nporls it from Popului frr- 

 monli in Jr. Ec. Knt. III. j). 374. 1911. 



LocalUi) — Tlif species as drscribt-d was taken in large numbers aloMj{ the 

 banks of the Santa Clara River near .Santa Paula, Cal. 



Dale of CoUcclion — .lune 'i'>. \[)\\. .Serial mniiber K). 



Figure 226. Pemphigus populimonilis Kiley 



L'n<li-r>i(le ol' ;i le.il' with the ^Ms opened so .is to show the .nphids .nml tlie larv.T 



of syrpbid flies. 



I have been .ilile to procure tbre<' descriptions of this insect; by Thomas (who 

 practically duplicates the ori|;in.'il description given by Dr. Riley), .lackson and 

 \\'illi;ims. From them I am led to believe that they arc all j)ractically the same 

 as that of the original description of Riley. Either the species wa.s originally 

 and afterward very jioorly described, or the species which I have described varies 

 a great deal from the individuals t.'ikiii in the East. The following difTerences 

 are noted : 



Size — .\ll of the above descriptions agree exactly regarding the size of the 

 species and their measurements are much less than those of the above specimens. 

 I'or instance. Thomas gives i\.V unn. as the average wing expanse, whiK> the 



