POTATO PLANT LOUSE. 253 



'Total length of body to distal tip of style and exclusive of 

 antennae, 4.05 mm. 



Apterous oviparous female. — Head pale, nearly white. An- 

 tennae with proximal joints pale, distal half dark. Length of 

 segments : III, .68 to .88 mm. ; IV, .56 to .68 mm. ; V, .52 to 

 .64 mm.; VI, .16 mm.; VII, .96 to 1.04 mm.; total antennae 

 length I to VII average about 3.6 mm. Prothorax and thorax 

 pale like head. Legs with femora and tibiae, proximal portion 

 pale, distal portion dusky. Tarsi dark, .16 mm. long. Hind 

 tibiae conspicuously darker and much swollen and thickly set 

 with senoria. Abdomen light salmon pink. Cornicles pale at 

 "base, distal half dark; length .6 to .8 mm. Style salmon pink, 

 ensiform, length .32 to .4 mm. Total body length to tip of 

 style, antennae excluded, 2.13 to 2.15 mm. The size of the hind 

 tibiae of this form makes it readily distinguished from the apter- 

 ous viviparous form and young, even to the unaided eye. 



The pink variety has been described because these predomi- 

 nate. The color scheme of the green and yellow forms can be 

 determined merely by substituting these colors for the salmon 

 pink of the individual described, the dark coloration being the 

 same for all 3. 



Winged male. — Head and antennae dark brown. Length of 

 antennal segments : III, .72 to .8 mm. ; IV, .48 to .64 mm. ; V, 

 .48 to .6 mm. ; VI, .16 mm. ; VII, 1.04 to 1.28 mm. ; total anten- 

 nal length I to VII, 2.93 to 3.60 mm. Prothorax and thorax 

 dark brown. Wings deflexed, hyaline, veins dark and very 

 -slender, stigma pale brown. Legs brown, darker at tips. Abdo- 

 men brown. Cornicles pale brown, dark distally, cylindrical, 

 .48 to .56 mm. long. Total body length exclusive of antennae 

 and cornicles, 1.12 to 1.57 mm. The thorax is large and strong 

 to support the wing muscles, the abdomen much shrunken and 

 is rendered conspicuous only by the comparatively (for the size 

 of the body) long cornicles. The male is described from speci- 

 mens observed in copulation, in order that no mistake as to 

 the identity of the species might occur. 



