MAPLE BARK LOUSE. Pukinceria Innu merabilis. Miss Emily A. Smith, of Illinois, one of the most accomplished entomologists of the West, says of this insect: Although the soft maple (Acer da-sycceiTum) is generally one of the first trees attacked, yet they soon spread to the other species. The insects live by puncturing the bark, and the females soon become clothed with a white, cottony substance, proceeding from the posterior parts. In this the eggs are deposited. The cut of the, insects, highly magnified, shows the female, and also their work on the bark; a, bark with insects at work; b, dorsal view; c, ventral view; d. beak. In the natural condition, the young insect settles down upon the leaves of the maple almost immediately after hatching, the preference being given the under side and near the midrib, although they are found upon the upper side to some extent; this is entirely owing to the number of insects upon the tree. When in a state of rest, the young lice draw the anten me under and parallel with the last joint of the fore pair of legs, the two remaining pair extend ing backward. During the summer the young insects increase in size, and continually grow darker. They molt several times during their growth, and do so by shreds of skin peeling off and not cast off entire, as in the usual way. Although they seldom leave the position first assumed, during the summer, they have full use of their legs, since when the leaf is detached from the tree, the young lice will withdraw their beaks and move quite actively about in search of fresh foc4. When young, the males and females can not be distinguished one from the other, but in a few weeks the males cease growing and change into the pupa state. The male scale is lighter than the growing females, and becomes longer and narrow. As the transformation pro gresses, two anal atylets project from the poste rior end, and soon after the end is slightly raised and the male comes forth, leaving behind on the leaf the whitish larval scale. These are found scattered about among the females, on both upper and under sides of the leaf. The male louse is very different from the female. During the pupa state he has acquired wings for the new sphere into which he is about to enter, and, although he still retains the legs and antenna, the beak and mouth organs are wanting, since, in the short existence granted him, there will be no need of food. The males generally appear the latter part of the month of July, and con tinue some two weeks. They are very active, flying about the leaves with great rapidity. At this time, impregnation takes place, the males dying shortly after, while the females remain on the leaves and continue to develop. We find that this louse is single brooded, the females living a few weeks over one year,the eggs depos ited the latter part of May, and the young lice appearing three weeks and a half after. That they settle down at once upon the leaves of the tree and remain until autumn, when they return to the under side of the leaves, remaining in this assumed position the remainder of their lives. The males appear in eight weeks after the young have hatched, and the females are then fully developed; in two or three weeks the males disappear entirely, while the females remain dormant on the limbs six months and a half of the entire year. It is well known that the varied temperature has great effect upon the length of time the insects remain in their several stages of growth. The manner in which this insect is
conveyed from place to place is undoubtedly through the transportation of the trees, the scales of the female adhering to the limbs when transplanted. The insects spread from tree to tree by the aid of the wind when in the egg state, the waxy mass becoming detached from the tree in very stormy weather, and, being light, it is easily blown about. Many flies, wasps and bees are attracted to the trees by the sweet substance in the waxy mass, and -the young lice, when crawling about, before settling down upon the leaves, will become attached to the legs of these insecta and thus conveyed to other trees. Nature has made violent efforts to assist in destroying the Pulrinaria innumerabilis, and one of the most successful ways of combating with this destructive insect is by cultivating and protect ing the natural enemies. To the lady birds we are the most indebted for services in this direc tion, since, unlike many kinds of insects, they continue their work of destruction throughout their entire active life, the larva and imago sub sisting upon the same kind of food. Three kinds of lady birds are very often found upon the infested trees during the summer months. The female maple louse has one true parasite, (Coccophagus Lecanii, Smith), which is double brooded, and lives in the body of the female. The insect is small, having a black body and four membraneous wings. The perfect insect and the pupa are shown at a, and b, the hair lines denoting the natural size. When the imago is about to emerge, the dorsal part of the louse becomes very black and presents a rounder appearance ; later the parasite makes a small circular opening, from which it takes flight. The first brood occurs in early spring, the second in August. Remedies: The fact that the young lice settle upon the under side of the leaf and limb, renders the use of fire extinguishers charged with liquid solutions possible and to good effect. When the lice are first hatched they are very small and delicate. A wash containing an alkaline solution applied at this time is sufficient to destroy them. By attaching a wire bag to a common sprinkling hose, filling the bag with soft soap and turning on the water, a soap-suds will be formed which will at once kill the insects. The scarcity of the water system in small cities renders this plan impracticable, however, and experiments led to a plan, easily attained by all, and which has proved successful the two seasons past. The plan recommended is as follows: Charge a fire extinguisher, in the usual manner, with bicarbonate of soda and sulphuric acid; add to the water one spoonful of crude carbolic acid to every eight gallons of water. Apply this to the tree; the force from the extinguisher will convey the fluid to all parts of the tree alike; the disposition of the insects to settle upon the lower surface of the leaf and limb serve to further this plan. Two applications should be made upon the same tree; the first, three weeks after the first deposition of eggs, and the second, four weeks from the first application. If the work is delayed, the insects become strong and the strength of the solution must he increased,which would be liable to injure the tree itself. The actual cost is not exceeding twenty cents an application, which is trifling compared to the cost of replacing the tree.