74G FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



We reproduce, with the author's permission, the greater part of Mr. 

 Scudder's pamphlet with the above title, published by the Massachu- 

 setts Society for the Promotion of Agriculture, Boston, 1883 : 



The piues on the island of Nantucket {Finns rUjida Miller), set ont some twenty or 

 thirty years ago, are fast dying iu large numbers from a cause hitherto unknown. 

 A great many have already perished, and most of the living trees look sickly. On 

 the " Old South Road," from Nantucket to Siasconset, all the trees on one side of the 

 road are quite dead, or fast dying, while upon the opposite they are comparatively 

 healthy looking, although seriously affected. 



On September 19, 1876, I went to this spot to discover, if possible, the difficulty. 

 I chose first a dead tree on Mr. Crosby's land, and cut it down, carefully examining 

 the trunk, boughs, twigs, bark, and roots ; there was no sign of the work of any 

 insect sufficient to have caused the death of the tree — none more than would be 

 found on any healthy tree. Next I selected a tree that was nearly dead, the upper- 

 most boughs only being in leaf, and a few bunches of needles appearing at different 

 points on the trunk. I cut this down and examined the trunk, boughs, bark, and 

 roots as before, with negative results ; but when I searched the living twigs I found, 

 always at the extreme tips, a great many recently dead needles, and in connection 

 with them a small lepidopterous insect, and in such numbers, both here and on hun- 

 dreds of trees afterwards examined, as to leave no room for doubt that this insect 

 is the sole cause of the trouble. The only other insect at all commou was the larva 

 of a geometrid moth, which had nibbled the leaves extensively, but not enough to 

 cause serious damage, or to strike at all at the life of the tree ; wherever the mark 

 of the blight was found upon living trees the first-mentioned insect was present in 

 vast numbers, and very nearly all the damage that had been inflicted was directly 

 traceable to its devastations. It is a minute moth of the family of Tortricidse, refer- 

 able to the genus Retiuia (or Coccyx of some authors), and may be described as fol- 

 lows : 



Head covered, especially above, with hoary tipped, smoky-brown scales, giving it 

 a speckled appearance ; palpi rather longer than the head, the middle joint expand- 

 ing into a compressed disk-like plate, half as large as the head, and covered with 

 silvery gray scales, which are dusky towards the base, the apical joint minute, slen- 

 der, dusky ; antenna} equally and narrowly annulated with dark brown and white. 

 Thorax and patagia of much the same color as the summit of the head, but the front 

 portion of each tinged with pale umber, while the hinder portion inclines to silvery 

 gray, sometimes to a decided degree. 



The ground color of the front wings is divided between a dull yellowish umber 

 and a deep reddish umber, deepening at points to a bright ferruginous. The former 

 prevails in the lower half of the outer two-thirds of the wing, and in an oblique sub- 

 apical band, subparallel to the outer margin. The latter elsewhere, but becoming 

 subinfuscated in the basal third of the wing; the brightest parts of this tint are 

 found in a large quadrate patch depending from the middle of the costa, and an 

 oblique, slightly arcuate streak, directed inward from the apex, and often continued 

 a little out of line over the lower half of the wing, breaking the lower pale patch In 

 the middle of the outer half of the wing. Both of these umber tints are overlaid 

 by frequent transverse, perfect or broken stripes of lustrous pearly gray, which, with 

 the diversity of the ground color, give the insect a very variegated appearance. 

 Nearly all of these pearly stripes run at right angles to the costa, and are distributed 

 as follows : The most Important and persistent are the two broadest, which divide 

 the wing into nearly equal thirds, the outer striking the inner angle of the wing 

 where the fringe terminates; another, nearly as constant, crosses the wing a little 

 beyond the middle, is slightly bowed outward, and united at the middle with the 

 outer of the two already mentioned, forming with it an H, with one straight and 

 one bowed leg; often, on the left wing, It more nearly resembles a K; besides these 



