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Willow Tree information


When the heart-leaved willow buds cast their leathery poke bonnets in spring, and begin to undo their bundles of young leaves, a four-winged creature wriggles itself free from its pupa case in a dead leaf at the foot of the tree, and tries its powers of flight. In the warm sunshine others of its kind are flashing their iridescent wings, and enjoying the delicious smell of budding willows.

They must all agree that there is nothing that quite equals it. "A short life and a merry" ­ this is their motto. The days of their revelry are soon over. Just before she dies, the female lays her eggs. Selecting a specially promising leaf on a willow twig, the insect settles down upon it. To look at her in this attitude you would think she had merely stopped to rest. Not unless you knew her by name would you suspect her of another motive, least of all of carrying concealed tools. If some one were there to tell you just in the nick of time that this is a saw-fly, you might see that a pair of slender saws were thrust back and forth out of a soccet on the under side of the abdomen, and that a slit was being cut in the leaf.

Into the slit the insect deftly slips an egg, and away she goes. Two or three hundred times does the saw-fly repeat this operation before her strength fails and death finally overtakes her. Her numerous progeny show many peculiarities, not the least of which is increase in the size of the egg before it hatches. The tender leaf swells and forms a gall around the young larva. By June the lump is as big as a cherry. It looks much like a red-cheeked apple. I was tempted to taste the first one I ever saw, and in so doing I found out two important things: first, that the soft white flesh of the "willow apple gall" tastes rather insipid; second, that it surrounds a central cavity which is almost filled by the body of the fat larva - white except for a pair of black eyes set in the pale brown head.

In the late summer I found the "apples" still fresh and rosy on willow leaves. Inside was the same little habitant, only older and larger grown. When his appetite is sated, and the faded leaf has fallen the saw-fly larva transforms into a pupa, and lies upon the ground all winter, exposed in its helplessness to all manner of dangers. Oh, well! There were three hundred of them. If two survive there will be no shortage of saw-flies next year, will there? Fancy the result if each of the three hundred eggs hatched and the young ones all grew up!

Nature seems most kindly disposed toward these little willow saw­flies. To live in a house whose walls yield abundant food and drink is the acme of luxury, truly. But life even in such a house is fraught with dangers. Birds mistake these galls for cherries, and many a robin, disappointed in the taste of the red berry, is pleasantly surprised and quite compensated by the juicy little grub that lie finds inside of it.

There is a little snout beetle that prospects in the late spring for a place to lay her eggs. Finding a small fleshy lump on the willow leaf, she wants nothing better. She probes it with her beak, pokes in an egg, and goes her way well satisfied. Out of this egg hatches a grub that soon destroys the rightful occupant of the gall, usurps its privileges, and assumes control. The Sycophant Curculio is its name. Often, instead of a beetle, a saw-fly plays the same trick. A poor relation is this larva which stays and stays, and taking the best of everything, starves his host. This insect has been called the Beggar Saw-fly.

Our sympathies are strongly enlisted in behalf of the helpless architect and inmate of the willow Apple Gall, who, by no fault of his own, falls into the hands of his enemies - and his relations. It is a relief to be told that all of his persecutors have enemies of their own that come into the gall after them. Nature seems to have no favorites among her creatures. The willow may prefer to have its leaves let alone by the saw-flies. The saw-fly mother knows not of the Sycophant Curculio, nor the Beggar Saw-fly. And perhaps neither of these two know until too late that there are insects whose larvae thirst for their blood. But each kind keeps down the numbers of the others. It is one of Nature's ways of maintaining the insect equilibrium.