416 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 3 



brown to almost black, indeed not only the color but the lengths of 

 the antennal segments and numbers of antennal sensoria vary so 

 much that I have been unable to distinguish between this speqies and 

 Oestlund's Ch. nigrce. 



* Callipterus (Pterocallis^) alni Fabr. : This species is rather com- 

 mon on the lower surface of the leaves of alders in the Chicago parks, 

 and when abundant, as it often is, the upper surfaces of the lower 

 leaves become heavily coated with the honey dew. I believe this 

 species has not before been recorded as occurring in the United States. 

 According to the table of American species of Callipterus given by 

 Mr. J. T, Monell," alni comes nearest to C. hyalinus Monk, from 

 which it may be distinguished by the blackish wing veins, the black 

 tipped cornicles, filament of antennal segment VI shorter than base, 

 etc. Inasmuch as there is no description of this species in American 

 literature, I describe in full the viviparous and sexual forms. 



Winged viviparous female. — Head pale greenish yellow, PI. 27, fig. 3, first thoracic 

 segment pale greenish, thoracic shield pale with a faint brownish tint, and abdomen 

 pale yellowish or greenish yellow with a more or less distinct dorsal transverse green 

 marking near the anterior end, another near the cornicles and a median longitudinal 

 marking, usually indistinct, connecting the two. Antennae about as long as the 

 body, segment III longest, IV about two-thirds the length of III, V a little shorter 

 than IV, base VI less than one-half the length of V, and filament VI slightly shorter 

 than base VI ; 2 to 4 large but rather inconspicuous circular sensoria near the base of 

 III, and the usual ones at the distal ends of segments V and base VI; I and II con- 

 colorous with head. III and IV pale (whitish) excepting the distal ends, which are 

 black, V pale at base and gradually darkening to blacldsh at distal end, VI blackish. 

 (PL 27, fig. 4). Eyes red. Beak rather short, reaching a little beyond the coxae of 

 the first pair of legs. Wings hyaline with rather conspicuous dark brown veins 

 which aie apparently bordered with an almost imperceptible pale browning tint, 

 stigma with a dark brown area at each end, stigmal vein hyaline or sub-hyaline 

 except the distal third. (PI. 27, fig. 5.) Legs pale excepting dusky distal ends of 

 the tibiae and the blackish tarsi. Cornicles tubercular and black excepting the pale 

 base. (PI. 27, fig. 6.) Style pale knobbed, anal plate very conspicuously bifid. 

 (PI. 27, fig. 7.) Measurements, — length of body, 1.4 mm., width, 0.53 mm.; length 

 of wing, 2.2 mm., width, 0.79 mm.; antenna, I, 0.05; II, 0.05; III, 0.4890-0.5460, 

 avg., 0.51; IV, 0.3079-0.3423, avg., 0.33; V, 0.2445-0.2934, avg., 0.27; VI, base 

 0.1141-0.1304, avg., 0.12; VI, filament, 0.0896-0.1141, avg., 0.0978; avg., total, 

 1.4278 mm.; cornicles, 0.05-0.06 mm.; styles, 0.115 mm. 



Wingless oviparous females. — Head pale greenish yellow, thorax and abdomen 

 pale greenish with darker green dorsal markings as follows: irregular transverse 

 patch near head, another narrower one anterior to the center and a third near the 



1 For the present I prefer to use the genus Callipterus rather than Pterocallis. 

 There is every gradation between the two so-called genera. If we take as a criteria 

 the characters for dividing the old genus Callipterus, used by several European 

 authors, there would be sufficient reason for the erection of several new genera 

 among the American species of Callipterus. 



2 Notes on Aphididae, Can. Ent., Vol. 14, Jan. 18S2, p. 13-16. 



