APHANIPTERA. Fleas.—Fleas are equally numerous, and may be seen in myriads in the dust of the streets or skipping in the sunbeams which fall on the clay floors of the cottages. The dogs, to escape them, select for their sleeping places spots where a wood fire has been previously kindled; and here prone on the white ashes, their stomachs close to the earth, and their hind legs extended behind, they repose in comparative coolness, and bid defiance to their persecutors.
DIPTERA. Mosquitoes.—But of all the insect pests that beset an unseasoned European the most provoking by far is the truculent mosquito.[4341] Next to the torture which it inflicts, its most annoying peculiarities are the booming hum of its approach, its cunning, its audacity, and the perseverance with which it renews its attacks however frequently repulsed. These characteristics are so remarkable as fully to justify the conjecture that the mosquito, and not the ordinary fly, constituted the plague inflicted upon Pharaoh and the Egyptians.[4342]
Even in the midst of endurance from their onslaughts one cannot but be amused by the ingenuity of their movements; as if aware of the risk incident to an open assault, a favourite mode of attack is, when concealed by a table, to assail the ankles through the meshes of the stocking, or the knees which are ineffectually protected by a fold of Russian duck. When you are reading, a mosquito will rarely settle on that portion of your hand which is within range of your eyes, but cunningly stealing by the underside of the book fastens on the wrist or little finger, and noiselessly inserts his proboscis there. I have tested the classical expedient recorded by Herodotus, who states that the fishermen inhabiting the fens of Egypt, cover their beds with their nets, knowing that the mosquitoes, although they bite through linen robes, will not venture through a net.[4351] But, notwithstanding the opinion of Spence[4352], that nets with meshes an inch square will effectually exclude them, I have been satisfied by painful experience that (if the theory be not altogether fallacious) at least the modern mosquitoes of Ceylon are uninfluenced by the same considerations which restrained those of the Nile under the successors of Cambyses.
The Coffee-Bug.—Allusion has been made in a previous passage to the coccus known in Ceylon as the "Coffee-Bug" (Lecanium Caffeæ, Wlk.), which of late years has made such destructive ravages in the plantations in the Mountain Zone.[4361] The first thing that attracts attention on looking at a coffee tree infested by it, is the number of brownish wart-like bodies that stud the young shoots and occasionally the margins on the underside of the leaves.[4362] Each of these warts or scales is a transformed female, containing a large number of eggs which are hatched within it.
When the young ones come out from their nest, they run about over the plant like diminutive wood-lice, and at this period there is no apparent distinction between male and female. Shortly after being hatched the males seek the underside of the leaves, while the females prefer the young shoots as a place of abode. If the under surface of a leaf be examined, it will be found to be studded, particularly on its basil half, with minute yellowish-white specks of an oblong form.[4363] These are the larvæ of the males undergoing transformation into pupæ, beneath their own skins; some of these specks are always in a more advanced state than the others, the full-grown ones being whitish and scarcely a line long. Some of this size are translucent, the insect having escaped; the darker ones still retain it within, of an oblong form, with the rudiment of a wing on each side attached to the lower part of the thorax and closely applied to the sides; the legs are six in number, the four hind ones being directed backwards, the anterior forwards (a peculiarity not common in other insects); the two antennæ are also inclined backwards, and from the tail protrude three short bristles, the middle one thinner and longer than the rest.
When the transformation is complete, the mature insect makes its way from beneath the pellucid case[4371], all its organs having then attained their full size: the head is sub-globular, with two rather prominent black eyes, and two antennæ, each with eleven joints, hairy throughout, and a tuft of rather longer hairs at the apices; the legs are also covered with hairs, the wings are horizontal, of an obovate oblong shape, membranous, and extending a little farther than the bristles of the tail. They have only two nerves, neither of which reaches so far as the tips; one of them runs close to the costal margin, and is much thicker than the other, which branches off from its base and skirts along the inner margin; behind the wings is attached a pair of minute halteres of peculiar form. The possession of wings would appear to be the cause why the full-grown male is more rarely seen on the coffee bushes than the female.
The female, like the male, attaches herself to the surface of the plant, the place selected being usually the young shoots; but she is also to be met with on the margins of the undersides of the leaves (on the upper surface neither the male nor female ever attach themselves); but, unlike the male, which derives no nourishment from the juices of the tree (the mouth being obsolete in the perfect state), she punctures the cuticle with a proboscis (a very short three-jointed promuscis), springing as it were from the breast, but capable of being greatly porrected, and inserted in the cuticle of the plant, and through this she abstracts her nutriment. In the early pupa state the female is easily distinguishable from the male, by being more elliptical and much more convex. As she increases in size her skin distends and she becomes smooth and dry; the rings of the body become effaced; and losing entirely the form of an insect, she presents, for some time, a yellowish pustular shape, but ultimately assumes a roundish conical form, of a dark brown colour.[4381]
