Pomona College Journal of Entomology 601 



Toxoptera aurantiae Koch. 

 CITRUS APHID 

 1*857 Toxoptera aurantiae Koch, Pflanzenlause pp. 254-255. 

 1880 Toxoptera aurantiae Koch-Buckton, Mon. Brit. Aphid, p. 135. 

 lyio Toxoptera aurantiae Koch-Fullaway, Rept. Hawaii. Agrcl. Exp. 

 Sta. pp. 3tl-,S1.2, for iy09. 



WINGED VIVIPAROUS FEMALE (Figure 196 A) 

 Lengtli of l)ody not inchiding style 1.6 mm., width of tlie me.sothorax 0.55 

 mm., greatest width of abdomen 0.75 mm., wing expansion (i.5 mm. A small black 

 form very common on Citrus in this State. 



Prerailing color — Black, shining. Head — Narrow, but wider than long, 

 black, with inconspicuous frontal tubercles. Eyes — Very dark red, almost brown. 

 Antennae — (Figure 196 D). On inconspicuous frontal tubercles, longer than the 

 body, but not reaching to tip of style, slightly hairy, articles I and II dark through- 

 out, III, IV and V all transparently light or amber with dusky tips, VI amber 

 with dusky band at nail-like process and at the tip. The lengths of the articles 

 are as follows: I, 0.1 mm.; II, 0.08 mm.; Ill, 0.37 mm.; IV, 0.31 mm.; V, 0.31 

 mm.; VI, 0.52 mm. (spur 0.42 mm.); total 1.69 mm.; article III (Figure 196 G) 

 has from six to eight large circular sensoria, IV (Figure 196 H) has one large 

 circular sensorium three-fourths the distance from the base to the tip, V has a large 

 circular sensorium near the tip, VI has the usual number of sensoria in the nail-IiKc 

 process. Rostrum — Reaching just beyond second coxae, light yellow with daik 

 base and tip. Prothorax — Twice as wide as long, shiny black, with distinct later il 

 tubercles. Mesothorax — Shiny black, muscle lobes prominent, making the raeso- 

 thorax much higher than the other part of the body. Metathorax — Narrow trans- 

 versely, black. Abdomen — Well rounded and smooth, shiny black or very dark 

 brown with several small lateral tubercles on the margins. Cornicles — (Figure 

 196 C). Short, cylindrical, widest at base and narrowest at tip, with inconspicu- 

 ously rimmed mouth, imbricated, black, length 0.2 mm., usually carried at right 

 angles to the main axis of the body. Legs — Rather large, hairy ; coxse black, 

 femora of fore-legs dark at tip only; femora of middle and hind legs amber with 

 all but extreme bases black; tibiae amber with bases and tips dark; tarsi dark. 

 Wings — Rather large and hyaline. Primary — Length 3 mm., width l.I mm.; 

 costal vein narrow and well defined, brown ; subcostal wide and dark ; stigma, the 

 most characteristic feature of this insect, is very black and can be readily distin- 

 guished by the naked eye, long and narrow with the longest sides parallel, pointed 

 at the tip, length 0.1 mm., width 0.15 mm.; stigmal arising near tip of stigma, well. 

 curved; first discoidal straight, light brown; second discoidal curved slightly in- 

 wardly, light brown ; third discoidal once-branched, the branch arising near the 

 middle of the vein (slightly nearer the tip from the middle), light brown. Sec- 

 ondary — Length 1.7 mm., width 0.5 mm.; subcostal extending to tip of the wing, 

 curved upwardly between discoidals, downwardly just beyond base of the second 

 discoidal, and thence upwardly to the tip ; veins light brown. Style — Conical, 

 hairy, black, length 0.1 mm., half as long as the conicles. 



