592 Pomona College Journal of Entomology 



light yellow with dark tips, tarsi dark. Style (Fig. 192, d and e) — Conical or 

 nearly cylindrical, hairy, dusky green to dark brown, length 0.13 mm. 



Young — Dark green or brownish. Some are slightly pruinose. 



Hosts — This insect has been taken in this locality only upon the tcndir 

 growth of orange trees. Near Pomona it was found by the writer several years 

 ago in great numbers feeding upon the tender shoots of young Valencia trees. 

 At Santa Paula it has been found only upon the suckers of the Havana Seedling 

 Sweet Orange. 



This insect is indeed a very extensive feeder and has been taken from over 

 fifty different plants throughout the United States. It was originally found upon 

 the cotton plant and has since proven a great melon pest. It is known by the 

 common names "Cotton Aphis" and "Melon Aphis." In this particular locality 

 there are numerous melon vines growing near orange groves which have been 

 infested with this louse, but I have never j'et found a single vine infested with 

 this louse. I recently received a shipment of eight distinct species of plant lice 

 from Imperial County, where the melons suffer from their depredations, but none 

 of them proved to be this species, although this does not prove that it does not 

 exist in that locality. It was not the most abundant this year if I may judge from 

 this sending. 



Locality — On citrus trees tiiroughout this State and also reported on various 

 other plants. Taken in Orange. Los .A.ngeles, San Bernardino and \'entura Coun- 

 ties by the writer. 



Date of Collection — This species, like Toxoptera aurantiae Koch, is most 

 abundant during the early spring months from February to ,Iune. Collected in 

 large luuubers at Santa Paula, Mav 17. 1911. Serial number (i. 



Natural Enemies — Subject to the attacks of the same natural enemies as are 

 described under To.voptera aurantiae Koch. 



In the Pomona College Journal of Entomology. \'(>1. I, pp. IT-tS. 1!)()9. I 

 described this insect as Aphis citri Ashmead. In tiie same Journal, \'(il. II. 

 pp. 22.S-22t, I9I". the species described as Aphis gossypii Glover has prov in to 

 be a new and distinct species and is herein described as .Iphis rdokii n. sp. 

 resembling the Pea and Rose .\|)hids. 



Macrosiphum citrifolii 1 Ashmead 1 

 18H'2 Siphoiiophora citrifolii .\shmead. C,in. Knt. \'ol. XI\'. p. 92. 

 WINGED viviPARors FEMALE (Figure 19.S A) 



I.engtii not including style 2.2 mm., width of mesothorax 0.7 mm., greatest 

 width of abdomen 0.9 mm., wing expansion 9-0 mm. A large green louse greatly 



Prevailing color — Bright pea green, shiny. Head — Slightly wider than long, 

 amber to pinkish yellow in color, with rather large antennal tubercles. Eyes — Red. 

 Antennae — (Figure 19-1' a). On rather large tubercles, longer than the body, with 

 very few hairs, articles I and II dusky green, III dusky amber with cvtreme base 

 light, IV^, V and VI dusky througiiout : the lengths of tiie articles are as follows 

 (although these vary greatly): I. I). II inni. : II. 0.08 nun.: III. 0.71 mm.; IV, 0.7 



