Coccus is a generic term - the typical genus of the great family, coccidae, which includes those insects usually designated "bark-lice," "scab lice," "scale-insects," etc., with their various adjectives. Whilst making my observations last summer, on the habits of the "Northern Lady-bird" (see November Number Gardeners' Monthly), I noticed a single specimen of a very convexed, chestnut brown coccus, nearly the size of half pepper corn, upon the same species of vine infested by the lady-birds, but not in exactly the same locality, although only about twenty feet from it. I made very little account of it at the time (July 5); it being on an upright of the trellis I supposed it was a dead subject of the previous year. Two or three days afterwards I was surprised to find it had shifted its quarters and was located on a leaf stem, for it is unusual for these insects to locomote after they once have fixed themselves and attained maturity. Within one week thereafter there were at least five hundred of those insects on that vine. They were of different sizes and colors, and were mainly located on each side of the midribs of the leaves, and on the stems, but only a few on the main vines.

None were of clear, positive colors, except the adults, and they were a smooth, glossy, chestnut-brown, slightly varying in shade according to age or state of development; also very convexed. These young resembled small species of cassida (coleopterous insects allied to the ladybirds), or like a minute tortoise with the upper shell ramified by veinations, and indented around the margin, and pinkish, greenish and whitish in color, but somewhat tarnished. They were all gifted with marked powers of locomotion, and changed their positions very often and very quickly, especially in the heat of the day. As in the case of the lady-birds, I permitted them to multiply to test their powers of destructiveness. Before the 1st of August there were thousands of them, and by the 1st of September, or earlier, including the quite young, they had increased to hundreds of thousands, if not millions. Many parts of the main vines, from one to two feet in length, were so completely invested by them that you could not stick a pin into it without passing through one or more of their bodies. Other parts, for a yard or more in length, had one or two uninterrupted rows upon them, and many of the leaves and leaf-stems were partially covered by them.

Earlier, these glossy brown convexities were filled inside with small whitish eggs, and even in this condition they had the power to slowly move about from place to place. The whole interior was an egg matrix or ovarium; the body consisting merely of an oval shell above, and just sufficient tissue beneath to admit the articulations of a beak, six delicate whitish feet, and antennae. Later, from these tiny eggs were exuded as many tiny insects, and these began to scatter as soon as they issued from under the body of the now defunct mother coccus - most of them only to perish. I attempted to count the number of young produced by one female, but I gave it up before accomplishing my purpose. They were so very minute, and scattered so rapidly that I abandoned it; but, judging from a count I once made of an allied species that infests the maple, linden, grape-vines, etc., I feel that I am making a low estimate when I say the number for each female is not less than five hundred and may be many more. On a small piece of the vine six inches in length were two hundred of the adult females, each capable of producing five hundred young, which would give us one hundred thousand, or two hundred thousand to a foot, or twelve inches.

Now, there were at least twenty feet so infested, which would foot up four millions in about two months, to say nothing of those that had matured earlier in the season, hatched their young, and then dropped off the vines to make room for others. Of course many of these minute insects never reach maturity, but perish in their infancy; and, doubtless, in the economy of nature their perishment is anticipated as essential to nature's general harmony. But those that do survive are capable of inflicting a great depletion upon the vegetation they infest. This vine became enervated sooner and more rapidly than the one infested by the lady-birds, although the insects confined themselves to pumping out the juice only. What they lacked in destructive energies they made up in numbers. It is these little things that are often the worst on account of their numbers and invisibility.

Now, this was a cucurbitaceous vine upon which they were located, and this suggests the query, What is to prevent them from infesting other vines of the same family, the cucumber, the musk-melon, the canteloupe, and water-melon, for instance? Their partiality or love for this plant is emphasized by the fact that, although a grapevine was in immediate juxtaposition, and their laterals intertwined, I only detected two or three adults - and none of the young - on the leaves of the grape-vines during the whole season. I have frequently found species of these prolific coccidians and their allies, on oaks, plum, peach, apricot, apple, and other trees, but I never noticed them before on succulent vegetation or annuals. This location may have been one of the blunders, which even the insect world is not free from. A succulent plant that grows up from a seed in the spring, and dries up and falls to the ground in autumn, is not the place to perpetuate sap-sucking insects. These insects kept hatching out and traveling over the vines and elsewhere, up to the month of October, and from the characteristics of these little atoms, as exhibited during the summer, vitality could not be sustained without being supplied with "green food," and a living woody branch for their winter quarters.

My impression is, that all this late hatching perished, except perhaps a fortunate few who may have found their way into a greenhouse, or a private conservatory. As long as the eggs remain unhatched and are favorably located, the winter's cold, no matter how prolonged, would have no injurious effect upon them.

The case is similar with the silk-worm eggs packed in China and Japan; sent across the Pacific ocean to San Francisco; from thence across the American continent to New York, and again from thence across the Atlantic ocean to Europe, to be distributed among the silk-growing countries there. As long as the non-incubating temperature remains intact, the enterprise is successful; but, should the temperature, from any cause, be raised to the point of incubation and exudation, the young brood would inevitably perish, and the enterprise fail. Never having noticed this species under similar circumstances before, I became doubtful of its specific identity, hence I sent specimens of it, and also notes of my observations, to the Entomological Bureau at Washington, D. C, and was informed that it was a common species, infesting greenhouse plants, especially further south, and that my record of finding it in the open air, in a latitude as far north as Lancaster, was an interesting fact in its history. It is one of the few species of the coccidae, of which the adults have the powers of locomotion, and this adds to its noxious character by increasing its ability to spread. It appears also that the male of this species has never yet been discovered - at least, it has not yet been identified.

I have never heard of it, nor have I ever seen any published statements of it, as a greenhouse pest in Lancaster. How it happened to invade my premises is involved in conjecture. Possibly some member of my family may have purchased an infested plant in market, without knowing it to be infested, - possibly not. This supposition is not only possible, but also very probable, especially in the first stage of the insect after it comes from the egg. It looks like a minute grayish atom of dust; invisible to the naked eye, to about seventeen in twenty, and hardly definable under a pocket miscroscope. Its length is scarcely 1 mm., and its breadth about half that quantity. Its form is oblong-oval, a little larger at the anterior than the posterior end. The latter is armed with two white, bristling filaments, and the antennae are armed with a few lateral bristles. Their color under a microscope is a dirty white, but to the naked eye they are dust-gray. Of course, it is impossible to say, without a peradventure, that these insects absolutely cannot bridge over the frigid chasm of winter, so far as the late hatched young are concerned; still, as many of the adults trans ported themselves to other situations, on the wooden trellis and on a contiguous fence, we will have to wait for another season before we can determine or not, their survival of a northern winter in the open air.

Should the "worst come to the worst," as a cu-curbitaceous pest, the remedy to destroy them would be very simple and easily applied. A liquid spray of Paris green, or even of soap-suds or tobacco water, would certainly destroy all the young if applied just when they begin to scatter, although it might have little effect on the adults; but these die of their own accord as soon as the eggs are hatched, if not before. As they continue their propagations during two or three months in summer, the proper time can only be determined by close observation, when to apply a remedy.