APPLE-ROOT BLIGHT INSECT DESCKIBED. 9 



until autumn, when winged individuals are developed, which 

 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 yeat. 



ThS young 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 

 ■ shortishj robust, and nearly equal in length. The antennae ap- 

 peared mueh like a fourth pair of legs, being robust, and about 

 the same length as the legs; they seemed to be five-jointed, the 

 joints successively diminishing in diameter, the one next to the 

 last being longest. From the tip of the abdomen of each of 

 these young lice protruded a white filament, or short thread of 

 flocculent cotton-like matter, variously curled and crinkled in 

 different individuals. 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 

 whoUy 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 hund- 

 dreths of an inch across. The body, legs and antennae are coal black; the antennae 

 are about half the length of the body, and the head and abdomen 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. ThJis cloudiness is rather more 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 mai-gin. The second vein is rather more robust than the first, is thickest in 

 its middle, at its base curved towards the tip, middle portion straight, apical third 

 curving towards the mner 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 refiection 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 



