221 



distinct slit is visible dorsally from the anal opening to tlie hiiul margin of tlie body; 

 projecting from the aual opening is a conical truncate organ bearing a central 

 papilla. Legs extremely short and stout, almost rudimentary and difficult to dis- 

 tinguish. Antenna' in this stage have not been made out. Third stage. Almost pre- 

 cisely resembles second stage except from its greater size. No sex distinction yet 

 noticeable. Fourth stage. Length about 1.4""", width, 1"'"'. Quite similar to third 

 stage, but all marginal tubercles and bristles are lost except a minute bristle on each 

 side some distance anterior to the terminal cleft. Dorsal surface densely rugulose, 

 with numerous fine and granulate stri«, becoming more distinct toward the margin, 

 giving this almost the appearance of being serrate. Shape broadly oval, flat, with 

 a slight median longitudinal carina crossed by 12 short transverse ridges indicating 

 the segments. Color, pale green, almost translucent, and resembling so closely the 

 appearance of a leaf that the insect is extremely difficult to detect with the naked 

 eye. Dividing line between head and thorax, with transverse dorsal ridges and 



Pig. 2i.—Aleyrodes citri Riley and Howard : a, adult male seen from side and .showing waxy tufts, 

 b, anal sei>;ments and claspers of same seen from above ; c, adult female seen from above, with wings 

 spread ; d, anal segment and ovipositor of the same ; e, head of same from side ; /, antenna of same ; g. 

 costal border of fore-wing; /(, hind tarsus; i, hind tibia: a and c enlarged, b, d. e,f, g, h,i still more 

 enlarged (original) . 



margins of the anal cleft sometimes pale yellowish, with the anal opening more or 

 less distinctly orange ; eyes invisible ; legs and antennje short and stout, the latter 

 appearing inarticulate; tarsi terminating in a large sucking disk. 



Pupa (Fig. 23 g). — Length, when fully mature, 1.4"'"', transverse diameter, 0.8""'^ 

 to 1"""^ ; broadly oval ; color, pale greenish-yellow, becoming more yellowish when 

 maturing ; thoracic lobes and spaces between dorsal carinas of abdomen ot a brighter 

 green ; a distinct orange or sometimes quite bright red medio-dorsal spot at anterior 

 end of abdomen; aual ring, brown; eyes, puri)lish. A low medio-dorsal ridge or 

 carina and corresponding depressions each side of it extends from the head to the 

 anal ring, traversed by short transverse ridges on the thorax and on the abdomen, 

 terminating in alow subdorsal ridge; from these ridges numerous very fine granu- 

 lated striie radiate all around the body to the lateral margin; a short transverse 

 ridge near posterior margin of head and a curved impressed line in front of it. A 

 miniite brown tubercle at the anterior end of the subdorsal carina. From a ])ore at 

 the edge of the body, between the head and thorax and tip of anal slit, issues a very 



