The Lace-wing Fly
LACE indeed! Was ever lace even of fairy queen fashioned so daintily as are the wings of this diaphanous pale green sylph, that flutters in its filmy halo above the grass tips? Yonder it alights upon the clover. Let us steal closely upon its haunt. Here we find it hid under the upper leaf, its eyes of fiery gold gleaming in the shadow, its slender body now caged within the canopy of its four steep, sloping wings, their glassy meshes lit with iridescent hues of opal—the lace-wing fly, a delight to the eye, but whose fragile being is guarded from our too rude approach by a challenge to our sense of smell, which plainly warns us, "Touch not, handle not!" Our first capture of the fairy insect is always a memorable feat, with its lingering, odorous reminders, which not even soap and hot water will entirely obliterate from our finger-tips. But why should we have caught her? What an opportunity we threw away in her capture! Why not, rather, have followed the gauzy sprite, and learned something of her ways, something of the mission she is performing as she flits from leaf to leaf? For this is no idle flight of the lace-wing fly as we see her in the summer meadow. Her golden eyes are on a sharp lookout for a certain quest, and we are fortunate if we chance to surprise her softly at the time of her discovery, and with breathless stillness encourage her in the fulfilment of her plans. Everywhere among the grasses, weeds, and bushes we find the airy tokens of her visits; those delicate, hair-like fringes surrounding culm or twig, or growing like a tiny tuft of some webby mould upon the surface of leaf. But who even guesses the nature of the pretty fringe, or even associates with it the pale green golden-eyed fly which we all know so well?
Here beneath our close leaf is an opportunity which we must not permit to pass. Even as we take another cautious peep we discover that a cobwebby hair has grown from the surface of the leaf, with its tiny knob at the summit; and now another is growing beside it, following the pointed rising tip of the insect's slender tail. It has now reached a half-inch in length, when the little knob suddenly appears and is firmly glued to the summit of the hair. Another and another are added to the group, until a complete tuft or fringe hangs beneath the leaf. Of course the reader will have now guessed the secret of the episode—that this is a mother lace-wing fly thinking only of her future brood. But what a unique method she employs in egg-laying! What seeming reckless consideration for her offspring! Fancy awakening from one's crib only to find one's self on the top of a telegraph pole, or clinging for dear life at the end of a dangling rope or rod! Yet such is the initial experience of the baby lace-wing flies as they emerge from their filmy, iridescent cradles, whose very first experience in life must needs be a daring feat of acrobatics. But hunger is a mighty incentive to work and daring deeds, and the lace-wing infant is born hungry, grows hungrier with each moment of its subsequent life, and is apparently the more famished in proportion to its gluttony, fully realizing the comment of Josh Billings upon the voracious billy-goat, "All it eats seems tew go tew apetight."
We may be sure that this gauzy mother-fly, with her appetizing reminiscences of her former epicurean days, has placed her progeny in a land of plenty—a land almost literally of "milk and honey." For wherever we find this delicate fringe of pale green eggs we may confidently look also for its counterpart—a swarm of aphides, or plant-lice, somewhere in the neighborhood, occasionally clustering about the very stalks of the eggs, and shedding their copious "honey-dew" for the benefit of the caressing ants, which sip at their upraised, flowing pipes. Ah! if these happy ants only realized the menace of this slender fringe—who knows but that they may?—how quickly they were to be cut down by the destroying teeth!
Here, for instance, a wee babe just out of the egg slides down the stalk, and falls plump among a whole family of the aphides. In a twinkling a young aphis larger than himself is impaled on his sharp teeth and its body sucked dry. But this is merely an appetizer; he has only to extend his jaws on right or left to secure another similar morsel, which is emptied in the same manner, and his first meal would only seem to be limited by the number of victims available, so insatiate is his craving. In a short time he must needs move up farther along the twig, and thus his swath extends, until within an incredibly short space of time the entire swarm of aphides has disappeared, leaving the field occupied alone by the larva, who has perhaps now acquired his full growth by their absorption—a full-fledged "aphis lion," as he is called. He is now about a half-inch in length, a long pointed oval in outline, the sides of its body beset with bristly warts, and its head armed with two long incurved teeth. But these teeth are not like ordinary teeth, constructed for "chewing" or biting, but rather for imbibing, and suggest the two straws in the glass of the convivialist; being tubular, their open points are imbedded within the juicy body of the aphis, which is soon emptied to the last drop.
The aphides are always with us. Where is the lover of the rose-garden who is not painfully familiar with the pests, their pale green swarms completely encircling the tender shoots, and shedding their sticky, shining "honey-dew" everywhere like a varnish upon the leaves and flowers beneath. Hardly a plant or tree escapes their parasitic attacks in one form or another, where, with their beaks imbedded in the tender bark, they suck the sap, and literally overflow with the bounty which they thus absorb and convert into "honey-dew."
We need not go very far in our country walk to discover our aphides encircling the stems of weed and shrub, and it is well the next time we encounter them to observe them more closely. They would indeed appear at first glance to be having things entirely their own way. Even here in my city back yard, for instance, upon my growing chrysanthemums, as I sit at the back windows some twenty feet distant, I can distinctly see their brown, disfiguring masses completely inclosing the under tips of nearly all the branches.
Again and again have I shaken or brushed them off only to see them increase and multiply; and, on the other hand, on more than one occasion have I seen an entire swarm vanish from a particular twig which I knew was infested only a day or two previous. Why? It was not that the aphides had completed their growth and died or fled. A careful examination among the young leaves or along the stem in their neighborhood showed the author of the havoc, a fat aphis lion, perhaps, in the act of sucking the contents of its last victim, or, perhaps, having completed his growth, contemplating the commencement of his cocoon in which to abide during the winter.
Almost any swarm of aphides will show us this fat wolf in the fold, and if not this particular one, another—perhaps two others—quite as voracious, one of them the fat larva of the lady-bug, and the other a tapering-looking grub with needle beak and insatiable hunger, the larva of the gold-banded flower-fly.
