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.

Eye Spy: Afield with Nature Among Flowers and Animate Things · 第 21 / 40 题