temperate regions. California, Florida, the Cape of Good Hope, the southern parts of Australia, Southern France and Northern Italy, and New Zealand are countries in which they are found out-of-doors in the greatest numbers. In England they are less troublesome in the open air, though in greenhouses and hothouses they abound; but, in places under glass, every gardener ought to be able to get rid of them without difficulty. For its extent New Zealand seems to furnish a larger number than any other country. The humidity of its climate and the absence of anything like severe winters in most parts of it are quite congenial to Coccids; and there is scarcely a tree in its forests or in its gardens, whether native or introduced, which is not subject to their attacks.

It has not been thought necessary to include in this work a list of the books and essays written on this family of insects. The list would be a very long one; but, besides that many of the books would not be obtainable here, it would be found that very many authors have done nothing more than copy—often quite blindly and unintelligently—what others had said before them; moreover, most of them are out of date. The student or the horticulturist desiring to know more about Coccids not found in New Zealand may find full details in the reports of the Agricultural Department of the United States Government, in Dr. V. Signoret's "Essai sur les Cochenilles" (Paris), in papers by Miss Emily Smith (American naturalist, 1878-80), &c. The American Departmental Reports of Professors Riley and Comstock, Mr. Hubbard, and Mr. L. Howard contain most valuable information. English works on the subject are mostly fragmentary or inaccurate; but Mr. Douglas, of Lewisham, has lately begun to discuss the Coccids in England in a systematic manner, and probably before long others will follow suit. In India, Mr. T. W. Atkinson, of Calcutta, is studying the family.

Natural science in these days tends ever more and more towards specialization, and the boundaries of scientific classes, orders, families, &c., are becoming always more and more narrowed. The student can find his time quite sufficiently occupied nowadays in the thorough investigation of so (comparatively) small a portion of the animal kingdom as is presented by the Coccids of even only one country; and the present work may not be without value to future workers in this direction. To the farmer, the gardener, the fruit-grower, and the owner of pleasure-grounds it is believed that the following chapters will also supply information at the same time correct, intelligible, and useful.

CHAPTER II.

CHARACTERS, LIFE-HISTORY, AND METAMORPHOSES OF THE COCCIDIDÆ.

The first principal character separating the Coccididæ from the rest of the Homoptera, and distinguishable without microscopic examination, is the absence of wings in the females at all stages of their existence.

The second principal character is the absence of any apparatus for feeding and digesting in the males.

From these two characters it follows that the females can only extend their operations by, at the best, crawling from plant to plant, or by being carried about by birds or other agency; also that the males cannot enjoy more than a very short existence, their work being entirely confined to impregnating the females. Hence, in any endeavours to destroy these insects, the males may be disregarded, and the females only attended to.

Other distinguishing characters, chiefly microscopic, are—

1. The presence of only one joint in the tarsus or fourth joint of the leg, in both males and females (Plate I., Figs. 6 and 7, ta);

2. The presence of only a single claw terminating the leg in both males and females (Plate I., Figs. 6 and 7);

3. The presence of only two wings, with two halteres, in the full-grown males (Plate XXI.);

4. The presence of two or more eyes or ocular tubercles, in addition to the ordinary pair of eyes, in the full-grown males (Plate I., Fig. 14; Plate VIII., Fig. 1, k, m).

I. The Female Insect.

In general outward appearance the female insects present very variable forms. They may be either naked, or covered over with some kind of a shield, which may be fibrous, or waxy, or cottony, or they may have simply a thin powdery meal scattered over them. The covered insects are, of course, stationary, although in some cases, before reaching their full development, they move about, carrying their houses with them. The naked insects may be either stationary or active.

They attach themselves either to the bark or stem of a plant or to the leaves. In the latter case it is rare to find them on the upper side; but, on turning over a leaf, the under-surface is frequently found covered thickly with them.

In many cases they exude, in the form of minute globules, a whitish, thick, gummy secretion, answering probably to the "honeydew" of the Aphididæ. This secretion drops from them on to the plant, and from it grows a black fungus, which soon gives an unsightly appearance to the plant. This fungus or "smut" is an almost invariable indication that a plant is attacked by insects,[C] and may, indeed, give a useful warning to tree-growers. It is not, however, produced in appreciable quantities by all species.

The manner of feeding upon the plant is the same as in all the families of Homoptera—namely, by means of a protruding rostrum, beak, or trunk, situated on the under-side of the insect. As there is not, in the female Coccididæ, any well-defined division between the head and the rest of the body, this rostrum is seen, on turning over the insect, in the form, usually, of a minute conical projection between, or nearly between, the first pair of legs, if the legs are present, or a little within the circumference, if the legs are absent (Plate I., Fig. 5). An ordinary lens will generally show, springing from the point of the conical rostrum, three or four longish, very fine, curling bristles. These bristles are, in fact, hollow tubes, and the insect, inserting them into the leaf or bark of the plant, sucks through them its food. It is thus plain that, with often great numbers of scale-insects sucking at