Pomona Collkoe Joubnal of Entomology 589 



frontal tubercles, nuifli sliortcr tlian the body, wry sparsely haired, dark through- 

 out except the base of article III, imbricated. The leiifrtlis of the articles are as 

 follows: I, O.I mm.; II, 0.07 mm.; Ill, 0.1. mm.; IV, 0.21 mm.; V, 0.21 mm.; VI, 

 0.4 mm. (spur 0.26" mm.) ; total l..S,9 mm. With sensoria on V and VI articles as in 

 normal forms, lioslrum — Reaching just beyond second e()xa>, amber brown with 

 darker bast' and tip. Prntlioiaj- — Sliglitly wider tlian head, with small lateral 

 tubercles. Abdomen — Well rounded, did! green, covered with Hoeculence, three 



small marginal tubercles on the sides. Cornicles (Fig , G) — Incrassate, nearly 



vasiform, imbricated, widest in middle and narrowest just l)efore the mouth, often 

 appear cylindrical with swollen tij), black, length 0.2 mm. Style (Fig , J and K) 

 — Conical or bluntly ensiform, rough, hairj^, black, length O.I !■ mm., shorter than 

 the cornicles. 



Young — Much lighter in color than tlie adults and ahuost destitute of the 

 white flocculence. 



Host — Orange trees, where it occurred in great numbers. 



Locality — Collected by Horticultural Inspector C. H. Vary at Pomona, Calif. 

 It has never been located anywhere else and cannot even be found tliere just now. 



Date of Collection — April 4, 1909. Serial number 36. 



The general appearance of this insect with its short antennae and cottony 

 covering is not unlike that of one of the members of the genus Lachnus and was 

 so recorded by me at the time it was first obtained. Strange to say, when first 

 collected by Mr. Vary it occurred in such numbers as to nearly ruin the infested 

 trees. Prompt measures were taken to hold the pest in check and it soon disap- 

 peared. Since then I have been unable to obtain fresh material. From the very 

 beginning it did not appear to be Aphis gossypii Glover, but I thought it might 

 be one of the various forms of that species and so described it as such. Since that I 

 time have sent specimens to various of the authorities on this group and have 

 received the following replies : 



"Your letter of the 13th ult. at hand and I have gone over the slides you 

 sent. I am returning them under separate cover and will say that those labeled 

 Aphis gossypii are not that species. . . ." — H. F. Wilson, Oreg. Agrcl. Exj). 

 Sta., Mar. 2, 1911. 



"I feel certain that the insect that you have figured as Aphis gossypii in quite 

 wide from that species. This insect is a very abundant one in Colorado upon our 

 cucurbitaceous plants, especially infesting the cantaloupe. I have also material 

 from the cotton plant in Texas and am quite certain that we have the species 

 correctly determined. . . ." — C. P. Gillette, Colo. Agrcl. Exp. Sta., June 9, 19IO. 



"Aphis sp.? No. S6. — It appears to be nearest related to A. gossypii, though 

 there are too many sensoria in the third antennal joint." — TJieo. Pergande, Bur. 

 Ent., U. S. Dept. Agrcl., June 12^ I9II. 



Not being able to place this as an already described species, 1 have felt 

 justified in calling it a new species, and have named it in honor of Prof. A. J. 

 Cook of Pomona College, whose work for the upbuilding of the citrus industry in 

 this State is well known throughout the entire countr}'. 



