APPLE-ROOT BLIGHT INSECT DESCRIBED. 9 



leave their retreat, and coming abroad into the open air, copu- 

 late, and search out new situations in which to plant their 

 species. Others, as I infer from the lateness of the season when 

 I found young lice upon the excrescences, remain in their abode 

 through the winter, to continue their operations upon the same 

 roots the following year. 



The yong larva: as appears from the hasty notes and sketch which I was 

 able to take whilst they were still alive, were scarcely four hundredths of an 

 inch in length, of an oval form and a pale dull yellow color. 

 Their legs were shortish, robust, and nearly equal in length. 

 The antennae appeared much like a fourth pair of legs, be- 

 jng robust, and about the same length as the legs; they 

 seemed to be five-jointed, the joints successively diminish- 

 ing in diameter, the one next to the last being longest. From 

 the tip of the abdomen of each of these j r oung lice protru- 

 ded a white filament, or short thread of flocculent cotton- 

 like matter, variously curled and crinkled in different indi- 

 viduals, The whiteness of this filament rendered it perceptible to the naked 

 eye, and served to show the situation of the insect as it moved about upon the 

 surface of the excrescence, when otherwise it would have been wholly invisible. 



The mature winged individuals are nearly or quite a quarter of an inch in 

 length to the tips of the closed wings, and these, when spread, measure thirty- 

 eight hundredths of an inch across. The body, legs and attennse, are coal 

 black; the attennse are about half the length of the body, and the head and ab- 

 domen on its back are covered with a dense mass of snow white or bluish white 

 flocculent down. The upper wings are transparent and slightly smoky, as 

 though fine dust had settled upon them. This cloudiness is rather mqre dense 

 at their tips. The veins are black, faintly margined with dusky brown. The 

 rib vein is robust, and from its base to the stigma, very slightly approaches 

 the margin, it then gradually diverges from it to the base of the fourth vein, 

 where it is more distant from the margin than in any other part of its course* 

 it thence curves slightly towards the margin, and joins it at a very acute angle, 

 the margin being commonly slightly contracted, or obtusely notched, at the 

 point of junction. The first vein curves slightly towards the tip on its basal 

 part, and then runs straight, or near its apex curves almost imperceptibly 

 towards the inner margin. The second vein is rather more robust than the 

 first, is thickest in its middle, at its base curved towards the tip, middle por- 

 tion straight, apical third curving towards the inner margin; its base is nearer 

 to the base of the first vein than to the outer margin, and it is about seven 

 times as far from the first vein at the apex as it is at the base. The third vein 

 is rather more slender than the first, nearly straight, sub-parallel with the 

 second vein two-thirds of its length, its basal third abortive and imperceptible 

 except in a particular reflection of the light, base about the same distance from 

 the base of the second vein that this is from the first, apex nearer the apex of 

 the second vein than this is to the first. The fourth vein is more robust than 

 the first and third, thickest at base and gradually more slender thence to the 



