Fig. 119.

The Linden Tree-borer (Saperda vestita of Say, Fig. 117) is a greenish snuff yellow beetle, with six black spots near the middle of the back; and it is about eight-tenths of an inch in length, though often smaller. The beetles, according to Dr. Paul Swift, as quoted by Dr. Harris, were found (in Philadelphia) upon the small branches and leaves on the 28th day of May, and it is said that they come out as early as the first of the month, and continue to make their way through the back of the trunk and large branches during the whole of the warm season. They immediately fly into the top of the

10000000

b

Saperda calcarata, larva.

tree, and there feed upon the epidermis of the tender twigs, and the petioles of the leaves, often wholly denuding

their eggs, two or three in a place, upon the trunk or branches, especially about the forks, making slight incisions or punctures for their reception with their strong jaws.

As many as ninety eggs have been

The grubs (Fig. 118e; a,

taken from a single beetle. enlarged view of the head seen from above; b, the under view of the same; c, side view, and d, two rings of the body enlarged), hatched from these eggs, undermine the bark to the extent of six or eight inches, in sinuous channels, or pen

etrate the solid wood an equal distance.

It is supposed that

three years are required to mature the insect. Various expedients have been tried to arrest their course, but with

branches of some of the trees have been washed over with

Fig. 122.

a

various preparations without benefit. Boring the trunk near the ground, and putting in sulphur and other drugs, and plugging, have been tried with as little effect.

The city of Philadelphia has suffered grievously from this borer.

Dr. Swift remarks, in 1844, that "the trees in Washington and Independence Squares were first observed to have been attacked about seven years ago. Within two years it has been found necessary to cut down forty-seven European lindens in the former square alone, where there now remain only a few American lindens, and these a good deal eaten." In New England this beetle should be looked for during the first half of June.

Monohammus titillator, larva and pupa.

The Poplar tree is infested by another species of Saperda (S. calcarata of Say). This is a much larger beetle than

Fig. 123.

a

those above mentioned, being an inch or a little more in length. It is gray, irregularly striped with ochre, and the wing-covers end in a sharp point. The grub (Fig. 119a; b, top view of the head; c, under side) is about two inches long and whitish yellow. It has, with that of the Broad-necked Prionus (P. laticollis of Drury, Fig. 120 and pupa), as Harris states, "almost entirely destroyed the Lombardy poplar in this vicinity (Boston). It bores in the trunks, and the beetle flies by night in August and September. We also figure the larva of another borer (Fig. 121c; a, top view of the head; b, under side; e, dorsal view of an abdominal segment; d, end of the body, showing its peculiar form), the Saperda inornata of Say, the beetle of which is black, with ash gray hairs, and without spines on the elytra. It is much smaller than any of the foregoing species, being nine-twentieths of an inch in length. Its habits are not known. We also figure, from the manuscript work of Abbot, the larva and pupa (Fig. 122, a, pupa; b, larva) of Monohammus titillator of Fabricius, but he does not state on what trec it feeds. We copy also a figure of the larva and pupa of Chion cinctus (Fig. 123, a, pupa; b, larva), from the same work. The author gives no account of its habits.

Chion cinctus, larva and

pupa.

SPRINGTIME ON THE YUKON.

BY W. H. DALL.

HAVING joined the readers of the NATURALIST in a winter day's journey on the Ulukuk portage not long since, we may, if so inclined, try our fortune again together, in the

more pleasant springtime, and gather what facts we may of interest and value during another day, spent on the great river of the northwest, and its shores.

The spring, after the middle of March, comes on with eager steps in the Yukon Territory. The days lengthen so rapidly that the change is almost perceptible from one day to another. The great snow blanket, from six to eight feet thick, which covers the whole country, sinks and hardens from day to day. A tremulous mist, quivering like the hot air above a heated iron, hovers over the brilliant surface of the snow crust, and to this is due the painful inflammation of the eyes (conjunctivitis) which is only too familiar to the northern voyageur under the name of "snow blind." To avoid it, we don a pair of dark green glass goggles, or the wooden goggles of the Eskimo, which admit the light only through a narrow slit in the blackened wood, warding off the reflected light; yet even through these the surface of a hill or river appears most dazzling, so intense is the snow glare. Early in April the long hot days and short nights are felt and their results indicated, by the water which covers and softens the ice sheets on lakes and rivers. Shirt sleeves are the rule, and open casements let in the unaccustomed sunlight without stint, while the dark parchment windows of winter are laid aside.

On the tenth of April, though the whole country was white with the half melted snow sheet, flies, to all appearance the familiar blue bottle and housefly, clustered in myriads on the sunny side of the wall of the Nuláto trading post. The same day I found the velvety crimson catkin of the alder (how many of our readers have ever seen it?) side by side with the silvery one of the river willow, and searching among the poplars for new arrivals, brought down a white-winged crossbill, the first of the season. A day or two later, the turfed roof of my log dwelling was alive with small steel green beetles, redolent with a musky odor, and by carefully scanning the few spears of dry grass and green

tufts of moss which appeared above the surface of the snow, I found several other smaller species sunning themselves, unconscious of the presence of an enemy. The short-tailed field mice (Arvicola xanthognathus and A. Gapperi) were waking up to a sense of the situation and enjoying themselves on the river bank wherever a projecting root or stone. offered a shelter from the keen eyes of the numerous hawks which ever and anon sailed overhead. Another reason for coming abroad was, that the melting snow was making their underground establishments very damp and uncomfortable.

The Canada jay, known all over the northern country by the less euphonious name of "whiskey jack," had already laid and almost hatched its eggs. The goshawk and the duckhawk (Astur atricapillus and Falco anatum) had put their nests in order, and some of them had one egg as an earnest of what was coming. The ptarmigan (Lagopus albus) began to show rich dark brown feathers on the head and neck and on the edges of the wings. Owls (Syrnium cinereum, Nyctea nivea, Nyctale Tengmalmi, etc.), were abundant and attending to pressing domestic affairs.

Toward the end of April I climbed a tall, dead stump, once a noble birch (Betula incana?), and found, in the cavity at the upper end, six smooth white eggs. While transferring them to my knapsack the head of the family came home, and careless of personal risk or even death, dashed wildly about my head, knocking off a loose cloth cap which I wore, and screaming with sorrow and anger. The female owl, for it was a hawk owl's nest (Surnia ulula), soon joined him; and they flew to the top of a neighboring spruce, uttering cries of indignation to each other. Reaching the ground I soon quieted them, bringing both down with a single shot, and thus devoted the whole family to the interests of science.

On the third of May, Kurilla, my indefatigable Indian hunter, killed a white-cheeked brant (Bernicla leucopareia) and two ducks, a mallard and a golden eye (Bucephala