210 MAINE AGRICULTURAL EXPERIMENT STATION. I915. 



nicies .96 to 1.04 mm. in length, and strongly reticulated at tip about 

 one-fifth tne distance. Cauda .56 mm. Total length of body to distal tip 

 of Cauda and exclusive of antennae, 4.05 mm. 



Apterous oviparous female. — Head pale, neaily white. Antennae 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, base .16 mm. ; VI, 

 spur .96 to 1.04 mm.; total antennal length I to VI average about 3.6 mm. 

 Ill with about 3 to 6 sensoria. 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 ana mucn 

 swollen and thickly set with sensoria. Abdomen light salmon pinic. 

 Cornicles pale at base, distal half dark and reticulated at tip ; length .6 

 to .8 mm. Cauda salmon pink, ensiform, length .32 to .4 mm. Total 

 body length to tip of cauda, antennae excluded, 2.13 to 2.15 mm. Tne 

 size of the hind tibiae of this form makes it readily distinguished from 

 the apterous viviparous form and young, even to the unaided eyt. 



The pink variety has been described because these predonnnate amo.ig 

 the oviparous females. 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 ill 

 three. 



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, 

 base .16 mm.; VI, spur 1.04 to 1.28 mm.; total antennal length I to VI, 

 2-93 l-O 3.60 mm. Sensoria numerous on III, usually none on IV, and an 

 irregular row of them nearly the whole length of V. Prothorax an.i 

 thorax dark browm. Wings hyaline, veins dark and very slender, stigma 

 pa.le brown. Legs brown, darker at tips. Abdomen greenish or brown. 

 Cornicles pale brown, dark distally and reticulated, cj-lindrical, .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, the abdomen much shruriken, 

 making the cornicles seem conspicuously long. The male is described 

 from individuals taken, in copulation, in order that no mistake as tu 

 the identity of the species might occur. 



INDOOR STUDIES. 



This potato aphid is amenable to laboratory or greenhouse 

 conditions, being very easy to rear indoors. In 1907 successful 

 colonies were reared by the writer on garden peas and shep- 

 herd's purse in the insectary, the insects being originally col- 

 lected from potato. The notes concerning these follow : 



July-October, 1907. By starting potatoes in the insectary 

 often, the aphids were supplied with fresh plants which were 

 colonized by the individuals deserting the leaves and stalks they 

 had rendered sickly. 



