Pomona College Joibnal ok Entomology 601 



Toxoptera aurantiae Koch. 

 CITRUS APHID 

 1857 Toxoptera aurantiae Koch, Pflanzcnlausc pp. 251-255. 

 1880 Toxoptera aurantiae Koch-Buckton, Mon. Brit. Aphid, p. I.S5. 

 1910 Toxoptera aurantiae Kocli-Fullaway, Rcpt. Hawaii, .\grcl. Exp. 

 Sta. pp. 3U-.Si2, for 190y. 



WINGED VIVIPAROUS FEMALE (Figure 196 A) 

 Length of l)ody not including style 1.6 mm., width of tlie mesothorax 0.55 

 mm., grcate.st widtli of abdomen 0.75 mm., wing expansion ().5 mm. \ •.mall black 

 form very common on Citrus in this State. 



Prevailing color — Black, .sliining. Head — Narrow, but wider than long, 

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

 Antennae — (Figure I96 I)). On inconspicuous frontal tubercles, longer than the 

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

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

 with dusky band at nail-like jirocess and at the tip. Tlie lengths of the articles 

 are as follows: I, 0.1 mm.; II, 0.08 mm.; Ill, 0..S7 mm.; IV, 0.31 mm.; V, 0.31 

 mm.; VI, 0.5'2 mm. (spur O.t'2 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-li<e 

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

 base and tip. I'rothorax — Twice as wide as long, shiny black, with distinct later A 

 tubercles. Mesothorax — Siiiny black, muscle lobes prominent, making the meso- 

 thorax much higiier 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.^ mm., usually carried at right 

 angles to the main axis of the body. Legs — Rather large, hairy; coxa- 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. 

 If'ings- — Rather large and hyaline. Primary — Length 3 mm., width 1.1 mm.; 

 costal vein narrow and well detined, 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 stiguia, 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..") 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. 



