Some of the more common Western lady-birds: 1, 2, 3, larva, pupa and adult of Cycloneda abdominalis; 4, 5, pupa and adult of Cycloneda sanguinea; 6, Cycloneda oculata; 7, 8, 9, larva, pupa and adult of Chilocorus cacti, closely resembling C. bivulnerus in all stages; 10, 11, 13, larva, pupa and adult of Hippodamia ambigua; 13, Coccinella 5-notata, var. californica; 14, Hippodamia convergens. Small beetle figures indicate natural size. (From Division of Entomology, United States Department of Agriculture.)

Occasionally a species that is normally a feeder upon plant lice may, when its food becomes scarce, attack vegetation, and under such circumstances some species have been found eating into the kernels of corn. Of the forms that are predatory, by far the great majority feed upon plant lice. A considerable number will feed upon scale insects, if no other animal food is to be had, but there is only a small proportion, in our country at least, that feed exclusively upon scale insects.

The most common, as well as the most effective scale-feeder in the United States, is

CHILOCORUS BIVULNERUS Muls.

(The twice-stabbed Lady-bird.)

This insect occurs from the Atlantic to the Pacific Coast, and from Massachusetts or even further north, to Florida; becoming much more abundant in the southern parts of the country. It is black in color, shining, almost hemispherical in shape, and on each wing cover, a little before the middle there is quite a large, dull, orange or bloodred spot; from which the insect derives its common name, "twicestabbed." In size it varies from an eighth to three-sixteenths of an inch in length, and as increased length is also accompanied by increased breadth and thickness, the largest specimen seems more than double the size of the smallest. In California these insects may be found active at all seasons of the year, and they feed upon armored scales in preference; on the Pacific Coast generally preferring the pernicious scale to almost anything else. In New Jersey this same insect, which is also a native here, makes its appearance late in April or early in May, and nothing more is seen of it after the middle of September. Although I have made no direct observations, yet from the dates of the specimens that I have seen, and from the times that I collected them, two broods of this insect seem to be normal. The beetle hibernates and appears towards the beginning of May. It lays eggs, from which larvæ hatch about the tenth of that month or a little later, and sometime in July a second brood of beetles makes its appearance from these larvæ. In August the second brood of larvæ has been observed, and beetles apparently just issued, were found in September. It is possible, however, that in the southern part of the State there may be three annual generations. In California the number of broods has not been definitely observed; but judging from what I saw myself, there must be at least six. Such enormous

numbers of specimens as were found everywhere in California, I never saw in New Jersey, and evidently our climate is a serious check upon the increase of this species. As the scale breeds with us quite as rapidly as it does in California, it is obvious that this lady-bird can never be as effective here as it is in the more favored State. The eggs are bright yellow in color, and quite large in proportion to the size of the beetle. They are elongate-oval in shape, set on end in little groups, something like those of the potato beetle, and in a general way resembling the eggs of other lady-birds, which are not uncommonly found on leaves infested by plant lice. The larvae are very dark gray or blackish, spiny, and with a more or less well-marked whitish or yellowish transverse band across the middle of the body. This mark is quite characteristic and makes it possible to recognize the insect in this stage with great certainty. The larvæ feed preferably upon active young or recently-set scales, and where they are at all numerous undoubtedly destroy a great number. When full grown, the beetle larva attaches itself to the bark by the anal extremity, suspends itself head down, the skin splits, and the pupa wriggles partially out of it. In this condition it remains for a few days, until ready to tranform to an adult. This beatle I believe to be the most effective enemy of the San José scale in California. Combined with the Aphelinus, it has done most effective work in the southern counties, and is, I believe, largely responsible for the decrease of the scale in that part of the country. Though the species is also native with us, yet I imported several colonies of the Californian form in the hope that the breeding habits acquired in that State might lead to a more rapid development in New Jersey, and might give us at least one or perhaps two more broods in the course of the season. Whether this will prove possible or not, is a question.

EXOCHOMUS PILATII Muls.

(The Pilate Lady-bird.)

This insect resembles the twice-stabbed lady-bird in general appearance and markings, but is larger, attaining a length of one-quarter of an inch, and the red spot on the elytra covers a much greater space, actually and proportionately. It is also set farther forward, and in some cases touches the base of the wing covers. Instead of having a tendency to be circular or round, it is nearly always more or less

oblong or square. The most obvious distinction, however, is in the size. This insect has been observed feeding upon the San José scale in California, of which State it is a native. It is much less abundant, however, than the Chilocorus, and breeds very much more slowly. It does not make its appearance until well along in May or June, and seems to have not more than two, or at most three, broods in the course of the season. In fact, it acts in California much as the twicestabbed does in New Jersey, though it becomes more abundant there than our species does with us. Some colonies of this insect were also introduced into our State, and the specimens, when liberated upon a scale-infested tree, seemed to make themselves at home. An examination made in early fall, however, failed to detect any trace of them in any stage.

ORCUS CHALYBEUS Boisd.

(The blue Lady-bird.)

The insect is of a bright blue color, without markings of any kind, and is therefore easily recognized. It has the general shape of the twice-stabbed lady-bird, and is about the size of the smaller speci

mens.

It is a member of the same general group to which the Chilocorus belongs, and has much the same habits. It was introduced into California in 1892, and for a time gave promise of increase, spreading from the orchard in which it had originally been placed to several others in the neighborhood. Great stories were beginning to circulate concerning its efficiency on armored scales, but, unfortunately, instead of continuing to increase, it rather decreased in numbers, and at the time of my visit in California, was sparsely present only in the orchard into which it had been originally introduced. It was hoped that it would increase later in the season, but apparently it did not, and nothing could be found of it during the latter part of July, when an attempt was made to collect colonies for me.

RHIZOBIIDS.

The species belonging to this general series are all small, few of them as much as one-sixteenth of an inch in length and most of them much less. They are very convex, but a little oval in outline, and are black or a little bronzed in color. The surface is more or less covered with fine silky hair, among which are interspersed longer,

bristle-like processes, irregularly set on the surface. Taken as a whole, the home of these species is in the southern hemisphere, although some species are found north of the equator. More are found, however, in Australia and adjacent countries than elsewhere, and this region is the source of the forms that were introduced into California. Two species may be found there at the present time, of which the larger is

RHIZOBIUS VENTRALIS Erichson.

(The black Lady-bird.)

This is called ventralis from the fact that the under side of the body is largely red in color, in strong contrast to the uniformly black upper side. The insect is said to be a general scale-feeder; but practically it seems to be confined to soft scales in California. Its favorite food appears to be the black scale, which it attacks in all its stages and to which it is undoubtedly a formidable enemy. The exact history of the species in California has not yet been worked out; that is to say, there is no definite information concerning the number of broods or the amount of food and its kind that will be taken by a beetle or its larva in the course of its life. It is asserted by Professor Woodworth that the insect feeds by preference upon scales that are attacked by fungous disease, and, if this proves to be the case, its effectiveness is limited, since the insects eaten by it would have been killed at any rate. There is no pretense that this insect has been recognized as an effective enemy of the San José scale, and it was never found by me on infested trees. The species does not occur at all in many localities where the scale has been cleared out, and in fact the pernicious scale had been practically disposed of before Rhizobius ventralis was introduced into California. No particular effort was made, therefore, to introduce this species into New Jersey; nevertheless, quite a number of specimens were brought in with the other material, and these were liberated in the same way, most of them in the Riverton orchard of Mr. Edward Lippincott. Some colonies were also sent to Washington, D. C., to Dr. L. O. Howard, and these were freed in the orangehouses of the United States Department of Agriculture. In August, on the occasion of a brief visit to Washington, Dr. Howard and myself carefully examined the trees infested by the black scale where the lady-birds had been liberated; but no trace of them was found and no signs of any feeding upon the black scale.

The second species is