790 Pomona College JournjVL of Entomology 



Hosts — This insect is a bark feeder and may be found under the surface 

 of the ground or away out on the very tender shoots. I have never found it 

 feeding on the leaves, although Davidson states that it is found on the stems 

 and the leaves. The favorite locality is on the bark which is at least one year 

 old. In not a few cases it has been found four inches under the sand. In 

 such cases the insects are very light green and the dorsal markings distinct, 

 without any of the white powdery wax. I have collected it on Cottonwood 

 {I'opulus trichocarpa T. & G-.) infesting the younger twigs, and on Salix 

 laevigata Bebb., usually on the older bark. Davidson simply reports it on 

 Salix sp. 



Locality — Occurs in many parts of Ventura County and collected at 

 Ventura, Santa Paula, and Sespe. Davidson collected it in the vicinity of 

 Stanford University. 



Date of collection — From March 30 to August 5, 1911. It is still plentiful 

 to date (Sept. 5, 1911). Serial number 17. 



This species collects in large colonies, which in their compactness resemble 

 the colonies of Tuberolachnus viininalis (Fonsc.) Mord, described further on. 

 Among the colonies are to be found many of the Syrphid larvae and not a 

 few are parasitized. The species as it occurs here does not usually have the 

 dusky tipped cornicles, though they are to be found. Instead of the cornicles 

 being orange, they are more often light lemon yellow or nearly transparently 

 white. Because of these variations I sent specimens to Prof. Davidson to 

 compare with his types and he writes as follows: "No. 17 may be rufulus, 

 although the third antennal joint is rather long, and the cornicles are pale 

 at the apex." I can explain that the specimens sent to Mr. Davidson were 

 obtained under ground and were somewhat bleached, which undoubtedly had 

 something to do with the lightness of the cornicles. The difference in the 

 length of the third antennal article is not sufficient to justify any separation, 

 so I feel that the species is where it belongs. 



Aphis maidis Fitch 

 (Corn Leaf- Aphis) 



BIBLIOGRAPHY 



1856 Aphis maidis Fitch. Kept. Ins. N. Y. I, 318-320. From 1856 to 

 Feb. 20, 1909, see J. J. Davis in Technical Series No. 12, Part 

 VIII, U. S. Dept. of AgrcL, Bureau of Ent., pp. 227-232. 



1909 Aphis maidis Fitch-FuUaway. Ann. Rcpt. Agrcl. Dept., Hawaii, 

 pp. 441-442. 



litlO .l/(/n',s »ifl?(/w Fitcli-Williams. Aphidida^ of Nebr., pp. 47-49. 



wiNGi';!) VIVIPAROUS FEMALE (Figure 251, A) 



Lengtli of body 2.2 mm., width of the mesothorax 0.6 mm., width of the 



abdomen 0.9 mm., wing expansion 7 mm. Bof/i/^Normal size, slender, more 



than twice as long as wide, sliiny. I'rr vailing color — From a dark olive green 



t(i a dull bluish-bhick. llnul — Small, ucarlv as long as wide, with short hut 



