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Pomona College Journal of Entomology 



Bibliography 

 \'JOi) Pem,phigus rudicicola Essi";. P. C. Jr. Eiit., E. p]). S-10. orijfinal 

 description. 



1909 Trifidaphis radicicola (P'ssig) Del Guereio. Rivist.i di P.ital. V(tj;etalc. 

 Anno, in, p. 332. Placed in new genus. 



1 ;)().') T. radicicola Essig Del Guercio-Baker, P. C. Jr. Ent.. I,. ])]). 73-75. 

 Translation of Del Guercio's article. 



1910 T. radicicoln Essig Del Guereio-Wilson. Ent. News. XXI. p. l.J."). List 

 of Genera. 



1910 T. radicicola Essig Del Guercio-Essig. P. C. Jr. Ent.. II. pp. '283-28.5. 

 Wing variations. 



1911 T. radicicola Essig Del Guercio-Essig. P. C. Jr. Ent.. pj). 1 tl-152. 

 Host plants and synonymy. 



Pemphigus californicus Daxidson 

 (The Woolly Plant Louse of the Buttercup) 

 I9I" Pemphigus raiiuiicuii Davidson. Jr. Ee. Ent. Ill, })|). 372-373. Orig- 

 inal description. 

 1911 Pemphigus californicus Davidson, Jr. Ec. Ent. IV, p. H L Renamed. 



WINGED VIVIPAROUS FEMALE (Figure 223 A) 

 Length of body without flocculence 2.6 mm., width of mesothorax 0.9 mm., 

 width of abdomen LI mm., wing expansion 6.7 mm. Bodi/ — Covered with a long 

 white or bluish-white flocculence. Naked body of the typical Pe7nphigus shape, 

 thorax little wider than abdomen. Prevailing color — With the flocculence white 

 and black, without flocculence, black head, and thorax and dull green abdomen 

 with brown appendages. Head — Broad base and well rounded in front between 

 the antenuif, much wider than long, with two compound .ind three ocellar eyes, 

 black. Ei/es — Compound eyes very dark red with a marginal terete tubercle on 

 the after part; this tubercle is composed of two small ocelli (Figure 223, 2). 

 This is the only instance of this kind I have ever noticed and a character not 

 mentioned by Davidson in his description. Antennae — (Figure 223 C, E, F). 

 Arising from near the sides of the head, bases widely distant, reaching to second 

 abdominal segment; usually dark throughout; three a|)ical articles with lighter 

 bases, all light at articulations, apical half imbricated, with very few short hairs; 

 article lengths as follows: I, 0.12 mm.: 11. (».1'J umi. : HI. OAr> nun.: IV. 0.19 

 nnn.; V, 0.25 mm.; VI, 0.21 mm. (unguis or spur 0.03 mm.); total L.'it nun. 

 Articles I and II usually coe(|ual. III longest, nearly as long as IV and V together 

 and longer than I\' and \'I togetlur. IV sli(n-t<r than \'l. V longer than either 

 IV or VI, and iiiiirc Ih.in twice as long as ritlnr 1 (U- II. \'l. with base approx- 

 imately six tinu's as long as the unguis. Articles traversed by numerous long 

 transverse sensoria which are very unevenly distributed. Ill has from nineteen 

 to twenty-five, more often with twenty-oiu- : 1\". four to eight. In examining 

 eight articles there wrrr to be found one with four, one with fi\e. two with six. 

 three with seven and <iiie witli eight: article \'. with from one to four, thri-e .lUfi 



