1917] Colorado Species of Lachnus 139 



darker portion which exposes the yellowish color of the abdomen 

 beneath. On the under surface, the color is pale yellowish, more or less 

 heavily powdered everywhere with white. The distal ends of the 

 femora are dusky brown, or, in some specimens, almost black, especially 

 the hind pair. The cornicles are very small as in the apterous stem 

 mother; hind tibiae short, stigma of wing long and narrow and almost 

 parallel sided; length of body, 2.75; length of wing, 3.70; cauda short and 

 very broad and oval on the posterior margin, which is black; antenna, 

 1.14; hind tibia, 1.60; beak, 1.54; cornicles mammiform, smaller than in 

 palmer (B, about .11 high by .14 broad at the base; joints of antennae 

 about as follows: III, .44; IV, .19; V, .23; VI, .17; sensoria of the antennee 

 about as follows: III, 1; IV, 1; V, 2; VI, usually 1 or 2 small ones a httle 

 below the large terminal one; entire surface of the body, including 

 antennse, thickly set with long delicate hairs. See figures 7 to 10. 



In alcohol, the general color is pale yellow and the dorsum of the 

 abdomen is sprinkled with black specks and dashes. 



Oviparous Female. — General body color pale yellow, covered every- 

 where with white powder; form rather robust; thorax and segments 

 3 and 4 of the abdomen with broken transverse bands or dashes, and a 

 rather distinct transverse blackish band upon the fifth segment of the 

 abdomen between the cornicles; upon the other segments black patches 

 only are to be found. The cornicles are black, as are the eyes, distal 

 2 or 3 joints of the antennas, the tarsi, the extreme tip of the abdomen 

 above, the hind tibice and the distal ends of all the femora and the middle 

 and anterior tibi^ and coxae; cornicles rather small. When the white 

 powder is removed, the head and two anterior segments of the thorax 

 are dark brown in color; length of body, 3.45; width, 2; length of 

 antenna, 1.57; joints of antenna: III, .37; IV, .17; V, .20; VI, including 

 unguis, .17; sensoria as follows: III, none or 1 near distal end; IV, 1 or 2; 

 V, 1 or 2; hind tibiae with numerous sensoria distributed throughout 

 their length. See figures 11 to 13. 



Egg. — ^1.25 long and .55 in diameter. See figure 14. 



Alate Male. — General body color black or blackish; the body more or 

 less covered with white pulverulence, and, on the ventral surface, green 

 when the powder is removed; eyes, antennas, cornicles, tarsi, distal ends 

 of tibiae and the greater portion of the femora black; beak reaching the 

 tip of the abdomen; wings with costal margin and stigma blackish, the. 

 latter being rather long and broad; stigmal vein heavier than the cross 

 veins of the wings; first and second transverse nerves moderately strong; 

 the cubital vein with its forks very slender and scarcely visible in places; 

 length of body, 2.20; antenna, 1.34; hind tibia, 1.4G; wing, 4; antennal 

 joints 3, 4 and 5 with many tuberculate sensoria; III about 30; IV, 

 about 14; V, about 8. The hairs upon the legs and antennae are rather 

 long, thickly set and very slender. See figures 15 and IG. 



This species was first discovered by Mr. Bragg upon 

 Colorado blue spruce in Fort Collins. We have not been able 

 to find it upon other trees. Its rather close ally seems to be 

 L. palmer CE, but that species is very common and in no instance 



