everything outside of it. Here again it is important that the insects should be noticed and attacked when young, because if a start be made from a limited portion of a field, by isolating this infested part the rest may be saved. This method of furrowing or ditching is in general the most satisfactory one, and its results are good, so far as limiting injury is concerned, in proportion to the promptness with which the presence of the insects is noticed and the remedial measure is resorted to.

Occasionally, when the caterpillars are noticed in a very limited part of a field—usually the rankest and most thrifty portion-it will be possible to use kerosene for their destruction. If the caterpillars are already more than three-quarters of an inch in length, the kerosene should be used pure and should be thoroughly sprayed upon the infested plants when the insects are feeding in the early evening. This may kill the plants, but it will also kill the insects and will limit the injury at once. It is sometimes possible to cut down a small infested plot, leave it to dry during the day and then burn it over, destroying the worms with the cut grain. This measure, of course, must be used with care, in order to prevent the fire from running away and causing more harm than good.

In all cases it is important that measures should be taken early, and very desirable that the insects should be noticed as early in their career as possible, before they have spread over any large territory. They always start from some central point, and the sooner measures are taken after the start the more limited their injury will be. It is almost always safe to accept as a total loss any portion of a field that is badly infested and to adopt measures which will look chiefly to the protection of the balance of the crop. If we apply kerosene pure, it will probably kill most of the plants as well as the insects. If the application is made while the caterpillars are less than one-half an inch in length the kerosene may be emulsified and the emulsion may be diluted five times. This kills the insects at that stage of growth and will not be apt to harm the crop; but the application must be made very thoroughly, and in fact all measures will be found successful in proportion to the thoroughness with which the applications are made.

The Harlequin Cabbage Bug.

(Murgantia histrionica Hahn.)

This is an insect which, up to the present time, has not been injurious in the State of New Jersey. It has been, heretofore, known as a typical Southern insect, and has been one of the most difficult to deal with of all the pests there affecting cabbage.

In September, 1896, Mr. I. W. Nicholson, of Camden, notified me that some insect, theretofore unknown to him, was attacking his turnips and apparently doing considerable injury. Later, at my request, he sent specimens, which to my surprise proved to be this harlequin

Fig. 6.

d

The harlequin cabbage bug (Murgantia histrionica) in all its stages: a, b, larva or nymph and pupa; c, egg mass, natural size; d, e, same, enlarged, seen from side and from above; ƒ, g. adult at rest and with wings spread. (From the Division of Entomology, U. S. Dep't Agriculture.)

bug in all its stages, from the egg to the adult. The insect is not entirely new to New Jersey, for I have taken specimens fo several years past in the southern counties; but always singly and never as a pest in cabbage-fields. The species has been traveling northward from its southern home for a number of years, and Mr. F. M. Webster has very interestingly followed its track in the State of Ohio, noting a northward advance of something like 18 to 20 miles per annum. I have had the species from Pennsylvania on various occasions, and it has been claimed as an injurious insect there by several persons who have written me on the subject. There is now a strong possibility that south of the red-shale line in our State, the insect may get a foothold, and may become another serious pest difficult to be dealt with. It is well, under the circumstances, that the farmers should know the insect when they see it, and should have some idea of how to handle it. It may be said, in this connection, that Mr. Nicholson claims that he has never seen the insect before this year, and as Mr. Nicholson is a careful observer, the insect, if present at all, must have occurred in very small numbers to escape detection.

The harlequin cabbage bug is so called because of its mottled red and black color, which makes it easily recognizable in all its stages. Even the eggs, which are laid in groups, are banded pale yellow and black, so as to form quite prominent objects on the leaves. From these eggs hatch little black, yellow and red-dotted bugs, which at once begin feeding upon the juices of the cabbage plants, exhausting them and causing the leaves to lose vitality, eventually to dry, shrivel and die. As the bugs increase in size, rudiments of wings begin to appear, until, when full grown, they are about two-fifths of an inch in length and one-third of an inch in breadth. The figures herewith given illustrate all the stages, the colors being black, yellow and red. The insects live through the winter in the adult condition, finding shelter wherever they can in the fields, under rubbish, along fences overgrown with weeds, in outhouses and barns, in corn shocks, or in fact wherever there is an opportunity to hide and secure covering and protection for the winter. They make their appearance in spring as soon as the warm weather fairly sets in, and at that time feed on whatever cruciferous plants they are able to find. They are particularly fond of mustard, wild as well as cultivated, and up to midsummer seem to prefer radishes to cabbages. Eggs are laid on the under side of the leaves in double rows of usually about twelve, but sometimes more than twice as many. Their general appearance has already been described, and they hatch in from two to eight days, depending considerably upon the temperature. As soon as they are hatched the young begin their destructive work, and increase in size rapidly, reaching maturity in from twenty to thirty days after the eggs or laid. They grow very much more quickly in midsummer than they do earlier or later in the season, and have been reported as reaching full size in as short a time as two weeks. This enables them to produce several broods during the season, and of course each becomes successively more injurious. No observations have as yet been made upon the insect in New Jersey, therefore their exact life history with us is unknown, but we can count upon at least three broods, and probably a fourth as well. The insect, therefore, becomes most abundant on the late cabbage, or on other cruciferous crops which are raised in the fall of the year.

Remedial Measures.

As this is a sucking insect, feeding only upon the juices of the plants attacked, stomach poisons cannot be used for its destruction. The arsenites and similar materials are therefore excluded and kerosene or a soap mixture must be resorted to. The history of the insect in the Southern States indicates that it is an exceedingly difficult one to kill. Dilute kerosene emulsions are of very little use against the adults, and soaps are of practically no benefit-the insects resisting insecticide applications of all kinds very strongly. Pure kerosene, however, killed the bugs readily; but is equally effective against the plants, destroying them at least as quickly as it does the bugs. Practically, the best method of dealing with the insect has been the planting of a trap crop to attract them very early in the season and to kill off the first brood there. This trap may be either mustard or radishes, and it must be planted with the idea that it is to be sacrificed for the benefit of the cabbage or other later crop. Where early cabbages are to be set out, the field should be planted as much earlier as possible with either mustard or radishes, which will come up quickly and will be more attractive to the insects than the cabbage plants when these are put out later. When the bugs are noticed upon the trap crops, they should be sprayed with pure kerosene, which can be applied with a Vermorel nozzle from a knapsack sprayer economically and rapidly, and the application will probably kill, not only all the bugs, but the trap crop as well; so that it also will be out of the way. If desired, it can be plowed under, and this will destroy what few eggs may have been already laid upon the plants. Later in the season, when the insects attack cabbage, they are not so easily dealt with, because they cannot be readily reached by the sprays, and because kerosene is very injurious to cabbage. Mr. H. E. Weed, of the Mississippi Station, says that in his State, wherever the first brood was killed off as above described, they did not prove injurious; while elsewhere in the vicinity they were very destructive. The insects are said to be sluggish and to fly but little, remaining by preference in the field where they made their start. This lessens the danger of infection from a neighbor's field and gives the careful farmer the benefit of his applications. Mr. Weed further says that the eggs for the first brood are only occasionally laid upon cabbages where mustard or radishes are available, and that as a rule cabbages are not then attacked until the

eggs for the second brood have hatched. Where mustard is used as a trap crop, the insects can be beaten into pans early in the day. As already stated, they do not fly readily, and can be brushed or shaken from the plants without difficulty. The pan or pail should contain a little water and kerosene; enough to thoroughly wet the bugs that are put into it. This measure is perhaps a little cheaper than the direct applications of kerosene in a spray, and may be preferable in some instances.

Perhaps it would be as well to suggest here that it would be advisable not to have too many cruciferous weeds on the farm to serve as food plants for the bugs early in the season. These would furnish natural breeding-places, and would to a large extent lessen the value of any trap crop that may be put in.