Aphididae of Formosa.— 3. 89 



Pale green, witli the modian area of the dorsum dark green. Body wide, 

 somewhat eonvex on the dorsum, sparsely dusted with powder. Head fused with 

 tlie prothorax, provided Avitli a few very long hairs. Eyes composed of 3 facets. 

 Horns long, rounded at the apex, vei-y slightly dilated towards the base, almost as 

 stout as, or slightly stouter than, the 3rd antennal joint, not curved upward, almost 

 as long as the 1st and 2nd antennal joints taken together. Antennae rather slender, 

 4-jointed, with a few rather long hairs; the 3rd joint with the apical sensorium very 

 small; the 4th a little longer than the 1st and 2nd taken together; the relative 

 length of joints about as follows: III-32, IV-23 (10+4). Rostrum very short, 

 reaching beyond the front coxae. Thorax and abdomen provided with some long 

 hairs. Abdomen wide. Cornicles rather large, situated on the shallow cones which 

 are provided with somi; long hairs, the diameter much larger than the wax-pore. 

 Cauda rather small, almost as wide as the lobe of the anal plate, slightly constricted 

 at the base. 



Anal plate bilobed, with some long bristles. Legs provided with rather sparse 

 long fine hairs; tibiae stouter than the 3rd antennal joint; hind femora almost as 

 long as the antenna; hind tarsi very slightly shorter than the 4th antennal joint. 

 Wox-pores circular, subcircular or oval, not very large, arranged in a row on the 

 side of each segment as in 0. inmlarh v. d. Goot; the number in a single row is 



about as follows: head-3 5, prothorax -3, meso-and met:ithorax-3 4; the Ist 



abdominal segment-4, the 2nd abd. seg.-5 6, the 3rd, 4th and Stli abd. segs. each- 



4 5, the 6th, 7th and 8th abd. segs. each.-3 4 



Length of body.-about 1.6 mm. 



Ho8t.-7)(7K/;'ocatert«.s latiffovus, attacking the leaf. 



Distribution.-Formosa. 



A few wingless viviparous females were collected by the author on December 

 2, 1923. This apliis is very closely related to O. inmkms v. d. Goot and OMriatn 

 V. d. Goot, but differs from them in tlie antennal structure. 



Oregma oplismeni n. sp. 



(PI. X,B, figs. 6-7) 

 Wingless viviparous female. 



Blackish purjile. Body broad, somewhat depressed, densely dusted with powder, 

 as in 0. lanigcra Zehnt. Head fused with the prothoi'ax, with some very long fine 

 hairs. Eyes composed of 3 facets. Horns large, rather stout, broadest at the base, 

 tai)ering, with the apex sharply pointed, scarcely curved upward, about twice as 



