BIOLOGICAL STUDIES ON THREE APHIDID^. 167 



distal end of the thickened base of the fifth segment. Measurements : 

 Length of body, 1.098 mm. ; width, 0.469 mm. 



Male after third molt. — General color sulphur-yellow, shading to 

 greenish at extremities. Eyes brownish red. Other markings as 

 in earlier stages. Measurements : Length of body, 1.003 mm. ; width, 

 0.741 mm.; antenna, I, 0.007 mm.; II, 0.057 mm.; Ill, 0.102 mm.; 



IV, 0.133 mm.; V, basal, 0.095 nun.; filament, 0.191 mm.; total 

 0.705 mm. 



Adult male. — General color bright lemon-yellow. Eyes dark red- 

 dish brown. Antenna^ usually as long as body, the two basal segments 

 concolorous with the body and the others dark; antennse with a few 

 conspicuous hairs, there being 2 on each of the two basal segments, 

 5 on the third, and either 1 or 2 on the fourth ; circular sensoria* 

 numerous (at least 40) and irregularly placed on the third, 15 to 

 20 on the fourth, and a number at the distal end of the thickened 

 base of the fifth segment. Beak short, not reaching farther than 

 the coxse of the second pair of legs; its tip dark, the rest concolorous 

 with the body. Six distinct bristles project forward from the front 

 of the head and between the bases of the antenna\ On the dorsal 

 surface of the body are 8 rows of tuberculate bris'tles, 4 on each side 

 of the median line. There are also 2 rows of dark oval markings 

 on each side of the median line. Measurements (alcoholic speci- 

 mens) : Length of body, 1.12-1.30 mm. ; width, 0.45-0.50 mm. ; an- 

 tenna, I, 0.081 mm.; II, 0.005 mm.; Ill, 0.407 mm.; IV, 0.220 mm.; 



V, basal, 0.106 mm.; filament, 0.350 mm.; total, 1.229 mm. 



Eggs. — Color, when first laid, pale green, with a small dark spot 

 of obscure form showing through the egg-shell at one end. The egg 

 gradually darkens until it becomes a jet-black. There is no notice- 

 able change in color just before the young hatch. Form elliptical- 

 oval. Measurements: Length, 0.052 mm.; width, 0.3015 mm. 



BIBLIOGRAPHY. 



ISS.'i. Forbes, S. A. — Thirteenth Report of the State Entomologist of Illinois, 

 for 1883. <Ai)p. Trans. 111. Dept. Agr. for 1883, Springtiekl, Vol. XXI, 

 pp. 41, 42-46, PI. Ill, figs. 1-4. Separate : Springfield, 111. 



Chaitophonis flavtis, n. sp. Describes wingless and winged viviparous 

 females and pupa ; also injuries and natural enemies. Observed chickens 

 feeding on these plant-lice. 



1885. Forbes, S. A. — Fourteenth Report of the State Entomologist of Illinois, 

 for 1884. <App. Trans. III. Dept. Agr. for 1884, Springfield, Vol. XXII, 

 p. 70, pi. 6, figs. 1-4. Separate : Springfield, III. 



Slight contribution to life history. Could find no root form. 



1887. Oestlund, O. W. — Aphidid;ie of Minnesota. <Geol. and Xat. Hist. Survey 

 of Minn., St. Paul, Bui. 4, p. 40. 



Mentions it as not having been found in Minnesota. 



