Pastoral-Agricultural

New Zealand Mail, Issue 606, 15 September 1883, Page 11

Pastoral-Agricultural

By A. McKay.

MAN AND HIS GARDEN PESTS and parasites. Read at a 'meeting of “The Wellington Gardeners’ Mutual Improvement Society ” on the 6th of September.

We find ourselves cast on a world teeming with living organisms, animal and vegetable, ■ each and all of which display a marked tendency to prolong life and reproduce it. This is the predominating principle in animal life, asserting itself for the necessary preservation of the organisms which life has originated and attached to itself. _ If the world’s, organisms derived their food materials directly i from the raw elements of the earth, air, and water, there would be no stimulus for that restless energy and instinctive influence which produces the ■ struggle for life which we perceive going on around us. It is true vegetable organisms with some exceptions have been content to acquire their food in this unobtrusive way ; but not so the animal ; they are less easily satisfied, they insist on having their viands cooked by nature in , the shape of vegetable organisms, which they complacently devour as their natural right. An observer unconnected with our world, viewing its constitution would possibly find l no fault in the -animal feeding on the vegetable, as he would see plainly in the nature of things, that the former was in a position to render service to the latter which it could not riot do for itself, •and so far, the harmonious relations of the two kingdoms would be mutual. But let the observer’s . attention be turned to the 'living components of each kingdom separately, and see if the word “ harmony” has a place amongst them. In the animal world rie will find a state of perpetual fight between the races. Tribes waring.tribes, each endeavouring to snatch the materials of its sustenance from the other, involving life or death to either disputant. This is the sort of natural harmony, which man as the highest native agent, l has to preside over, and inodify to his necessities if he can. Then, if the principle of life-preservation in man and all animals virtually resolves itself into •a state of perpetual warfare, if the animal instinct directs the pursuit, and capture of the materials that support and prolong life, if the same principle evolves defensive means for dear life, then ‘surely man- is justified and bound to protect 4 to the uttermost the existence and welfare of his own race all competitors. Unfortunately for us, man is so constituted that his animal nature frequently drags him down from himself; and directs his destructive powers against his own •race, but which should alone be directed against his natural and persistent enemies. Evidently the leading principle iri animal r life is a harddhing to conquer or moderate. “Two dogs will fight for the possession of a bone ; and man—that almost god-like, creature—will act exactly in a similar manner, thereby betraying his humble connections in this world. Necessarily in a less appreciable degree the same principle is manifested in the vegetable world. 'We might expect to see in vegetable life passive submission to its,parasite aggressors and other assailants, but this would hardly be correct. The principle of self-preservation is manifested in various ayays in the different forms of organised life. Each species has it peculiar way of escaping from its foes. The same principle originates a kind of control or order by which a stronger species protects a weaker for his own private nse, and thus helps to perpetuate its species. In man this has developed into the acquirement of property, farming, gardening, and so forth. Whenever we farm „or garden, we vainly endeavor to make exclusively our own thafc.whieb all creation ha 3an equal right to; so that for the weliare. of our race we try to deprive other living creatures of the pleasure of feasting on that on which we want to feast. We even enforce order amongst ourselves, so that onr neighbor’s breakfast shall have due respect from us as belonging to him alone. We cannot instil similar , respect in the minds of the insects and animals that prey on our husbandry. We, therefore, look to their destruction as the only „ remedy, and the difficulty we have to " grapple with. We introduce and favor the species of one race because they are known to be the natural enemies of a race considerably destructive to our interests. This is simply

employing a lesser pest to check the ravages of the greater pests ; but in doing this we are liable to introduce an additional pest without deriving the advantage from it that we expected, as what is the natural enemy of a race in one country may not be so in another to anything approaching the same extent, owing to . the plentiful presence of more attractive fare. But in any case natural restriction of species can only be regarded as mere aids to us at the best so that greater attentio'n should be given towards the further development of our destructive powers. The plants and animals we utilise are also utilised, by myriads of other organisms, whose necessities are no less pressing than our own, so that we only reap a part of the fruits of our labor instead of a whole. To get the whole (putting weather accidents aside) we must be in a position to destroy the organisms that wrest the part from us. This brings us to the question whether cultivators should not limit the area of their operations to the given extent to which they can successfully protect the same from the aggressions of all competitors, whether animal or vegetable, or operate on a greater area, and be content with a part. If the latter method be adopted, we not only receive a less return in proportion to area, but we necessarily supply the natural enemies of that which we cultivate with the means necessary, and favorable for their propagation, and the further we do this, the securing of our husbandry will become a matter of proportionate difficulty to us. Plainly, then, we should confine ourselves to just so much as we can adequately protect, and no , more. In gardening, this course commends itself preeminently. Also, as we have got to regard all plants and animals, legitimate objects, to be utilised or destroyed by us as thought best, without reference to the objects them-

selves ; and as we consider ourselves supreme on this earth—in fact, its governing j parasite—no doubt we are justified in adopt- t ing the wisest course in destroying or checking all othe r parasities or organisms that materally interfere with the objects which wo cultivate. In our present state, we are hardly in a position to bring about the extinction of any of the little pests that annoy us, as the world is too big for our numbers, and perhaps, it would be inconvenient to do so if we could until such a time as we can manage our affairs without their aid. Clearly, then, all depends on our own management. We might substitute animals useful to us to do the scavenger work of cockroaches, rats or mice. We might confine the insect fertilisation of our flowers to the action of the honey bee, and harmless insects. We might ourselves by chemical means reduce the dead and decaying organic matters which are nowdealt with by fungoid life, and which neither animals nor insects care to finish off. That the policy of the future will take after this course there is very little doubt, as, although the various little orga nisms are useful in their way, yet many of them plague us heavily. The principle of self-preservation is too strong in them to stop at doingusaservice(toustheirlegitimate work); they mustalso thrive and rob us of that which we call our own, and we, animal like, retaliate on them accordingly. But haphazard, disunited battling with insect life is a hopeless task, unworthy of us, and at the best only gives temporary relief. We. have more natural or acquired enemies than any other organism on the face of the earth, because we utilise so much more. Consequently, there is more reason why mankind should act unitedly in checking his numerous foes. To facilitate action of this kind, every child, from the cradle upwards, should be taught to,'know our enemies and made adepts .in their destruction. The moths, beetles, eaterpillers, and so forth of a country should be as familiar in its schools, as books, pens, and marbles, and their habits and ways of living, explained side by 3ide with the mysteries of ABC. The play hours . would then be absorbed in bunting excursions in the fields, gardens, and highways. The grasshopper, the caterpiller, the moth, and the beautiful butterfly, would all alike fall victims to the keen laneelets of youthful play. Once insect hunting became a recognised play with school children, the meaningless play of hoop and marbles would give way to a useful, and perfectly natural course of healthful ' exercise, and give rise to a host of embryotic entomologists in the future who would thereby be infinitely more capable of dealing with insect life than their fathers were. Children will naturally carry the interest of .their youthful play into their manhood, which, with the experience and wisdom of that state,' will influence the evolement of further reaching means for the eradication of their persistent enemies, and erstwhile’playthings. At the present time ■ who but the educated scientist is conversant withy the various phases of insect or fungoid life. Certainly not those who have to battle with it. 1 Surely this is a case, of knowledge diverted from the legitimate channels for its practical use. But, if it is worth while —and experience says it is—to organise means equal to combat and check our numerous and destructive little foes, or even in time to attempt their extinction, the principle of hostility towards each and all of them should develop itself in us from babyhood upwards, and be a distinguishing characteristic of mankind. The encourage ment of such a principle is warranted by the attitude which naan has already taken up in -respect to the rest of the world. As man artifieiali.ses the face of the earth, the relations of its various organisms to each other must necessarily become modified in harmony therewith, or else go to the wall. Naturally the parasitically inclined races will be amongst the first to fall in with the altered state of things, and endeavor, to benefit’ by it, however man may disjoint the even tenor of Nature’s ways. The same cause , may help the extinction of other species less amenable to collateral changes, and so disturb the balance of the worlds’ life. Evidently under such circumstances the restoration" of the natural balance, if possible or desirable, must be brought about by other than natural means, except we are prepared to sacrifice our interests immediately concerned, which we do not care to do except as a last resource, as in the case of the phylloxera on the vine which puzzled the ingenuity of the world to subdue, and which at last had to be relegated to the process of natural starvation as a cure. Our very existence, depends much on the nonabnormal spread of insect life. Any accident which favored the undue multiplication of a single species may also make millions of ns bite the dust. We all know the desolating capabilities-of the locust. Should this . pest at any time overrun the world, what would our civilisation avail us if we could not manufacture food directly from the earth until nature could restore to us the needful materials ? We treat insect activety with careless indifference, till its damaging results compel our attention. Such results must continue to occur in the absence of a course of systematic repression. It is evident if we destroy insects on their first appearance in the winged state, the reproduc- . tion of their destructive larvae will be impossible. Unfortunately for us it is not always practicable to catch a butterfly on the wing, however dexterous the.hunter may be, but surely some inventive mind will produce an arm—otherwise harmless—which, in the hands of experts, will be capable of popping off moths or butterflies with ease, and besides, supply an additional rational and useful sport which will delight the hearts of a myriad of grateful boys. The loss which alone the beetle and butterfly tribes cause to us in the aggregate, may amount to a fourth of our crops and in the case of single crops, such as the tomato or the apple, we frequently lose a half. The loss caused by the larger eaterpillers is plainly visible to the eye in its progress, but the work of the larval of the beetle on our fruit trees, though equally destructive, is not so seen, yet the beetle is more often the cause of our apples falling from their high estate than most people are aware of, and so the wind gets the blame. Surely then, the value of our loss from insects would more . than pay the cost of elaborate means for their destruction. We find moths and butterflies most numerous during spring aud summer, but,

some variety or other will be seen during any month of the year, and although most of them fly about in the daytime some kinds confine their rambles to the evening, when they cannot bo seen, so that whatever traps we may place for them, must be available for their capture day and night and all the year round. One or two effective traps in e:y?li garden of a district might do much towards lessening the numbe-s of the these insects. Such traps might resemble miniature glass houses, inside of which a number of artificial flowers charged with prepared nectar, might be placed to entice our winged foes. Mirrored glasses might be used to magnify and heighten the attraction of its flowering contents. Such a trap would be particularly effective when outside flowers were rather scarce or during a low state of temperature, when such insects would naturally makefor the warm, attractive sunny spots. The probability of bee 3 being captured in such a trap would be extremely., likely, but an expedient for their liberation would form a part of the device of the inventor, and to whom I particularly refer the idea to be worked out. I shall now point to the probable direction in which these insects in the larvse state and most other insects injurious to us will be largely destroyed in the future, in the hope that something in this way will speedily be done to facilitate its accomplishment. In doing so it will.be unnecessary to refer to any of the many special insecticides in general use, each and all of which are effective in their way when judiciously applied in the form of • powder, or liquid solutions. . At the . same time we are but too well aware that in the application of either of them, ' a large amount of valuable time is expended, so that their use is confined to very infinitesimal limits, and this must necessarily he the case so long as the work is done by hand. This is where the point comes in. Insecticides are plentiful hut the means for their rapid application are wholly wanting. Undoubtedly, the gardeners of the future will have machines insecticide" applies, to raj— of far-reaching effect, available for the destruction of insect life throughout the garden of a whole district. Whatever the constructive nature of the these machines may be, it is evident they must be capable of distributing m large volume any .liquid solution in a state of fine spray or vapar, so as to speedily moisten the occupants of our beds and borders, and also with considerable force when required, A modification of the common garden engine might possibly produce the desired results.. Liquid solutions are considered most effective and economical when applied in a vaporous state. This is easily seen. A very small quantity of liquid. suffices to dew a given vegetative surface. From experiments made with a small vaporiser about 30 gallons is sufficient to the acre. , Suppose we had. to deal with an acre of roses badly infested with blight. We would.bring out our engine, or hire one, and fill in 30 gallons of water, adding 2oz.' insecticide to the gallon, which would cost about four or five shillings,' screw on the vaporiser, get a man to assist, and proceed to work. In the course of four or five hours work, the acre of roses would be enveloped in the dewy solution, and the apliisormildew,asthe casemay be,destroyed, providing, the volume emitted from the vaporiser equalled a square yard. The American blight or red spider in the orchard might next require attention. For these, it would be necessary to substitute a coarser distributor, capable, of delivering the solution with force,/ so as to penetrate or break up the woolly covering of the aphis and webwork of the spider. Thus, the same machine provided with a set of different distributors might be made to meet all requirements. The same force used in the distribution of liquids would be quite as applicable to solids in a powdered state, such as lime, soot, hellibore, or other powders for destroying slugs, grubs, &c. With the aid of such a machine the gardener might well feel secure from his insect enemies. It would save him the loss of much valuable time now occupied in washing, sponging, scraping, syringing, hunting, and killing by hand, and also save him the loss of many things impossible to be protected from insect destruction. It seems strange in these days of annual exhibitions of the world’s industries, that we hear nothing of insecticide-applying machines as occupying a place amongst agricultural machinery. Such machines would benefit the farmer no less than the gardener, and would be equally enconomical in protecting a district as a private garden. But no reform in our ideas or means for grabblingthe insect pests islikely to dcvelope so long as we are generally contented with a very imperfect knowledge of insect life. Gardening experience certainly tends to make us acquainted with the insects which annoy us most, but it does not give their natural history. Our interest in that which we cultivate influences us in destroying insects, but it does not point out the weakest parts or state of insects most susceptible to injury from us. The entomologists and anatomists know all about those things, but, unfortunately, none of their kind have as yet found their way into this society to further its usefulness. The weak point of most societies devoted, to the acquisition of gardening knowledge is their , absolute disconnection from societies of a kindred nature. But a drawback of this kind must not be allowed to deter us from following out a course of usefulness to each other. We must —para site like —appropriate the stored ud knowledge of workers who have trod before us in Nature's ways. It is riot enough that we should know everything in connection with the insects which are directly or iudirectly injurious to our interests. It is almost equally necessary to know correctly those that are if anything, advantageous to us. I may mention a case in point regarding some brown and black ants which ledmeinto serious error. Observing them display great interest in certain plant parasites, notably mealy bug, I concluded they must be the natural enemies of the parasites, and consequently looked forward to their extermination by the ants. However, instead of the parasites decreasing they increased wonderfully, and my faith in the ants vanished accordingly. Plants that had hitherto been clean, became suddenly infested with bug as if by magic. Cuttings which were placed in the propagating bed became infested in the same way and their growth totally arrested. The old materials of the bed were replaced with fresh materials and fresh cuttings but all to no pur-

pose, thepest werestill there. Careful watch ofthe movements of the ant showed that they did not killjthe parasites, but farmed them in the most approved way. Three cuttings of justicia were placed in the propagating bed, and the sand smoothed between them so as too readily show any alteration of surface. Next morning a tunnel was found to have been bored through the sand close to the stem of one of the cuttings. An ant carrying a full grown bug was observed to enter the tunnel, and disappear below. Shortly after, the cutting was pulled up, showing the bug adhering to the end of it, to all appearance quietly enjoying the parasitical dinner. When the two other cuttings were removed, a bug was attached to each in the same way, and one had given birth to a lot of young ones. On another occasion happening to see an ant carrying a bug up the partition of the house, I watched it make its exit over the topof the door, and throughinto the.vinery, thence on to the wire, till it reached the vine on which it deposited the parasite. Further inspection revealed the presence of a number of bugs on the vines, which, no doubt, were transported there by the ants. Whether the ants feed on matterexuded by the bug, or milk them as had been suggested, I was unable to ascertain, but that they facilitate the propagation and pread of the coccus and aphis tribes their arming proclivities abundantly testify. Poisoned sugar or tobacco smoke will kill ants, but their thorough extermination in the greenhouse is a matter of considerable difficulty, as they breep into the crevices of the building. On more than one occasion I thought I had seen the last of them take tlieir departure, disgusted by the persistently unfriendly attitude maintained towards them, but they have returned again and again, and even now it is a question whether the ant or the man.will be master .of the situation. Plainly, there is that in insect life which excites our admiration as well as our disgust when baffled by its instinctive qualities ; there is that in insect life which challenges the ingenuity of man to thwart and subdue to his.will. There is in the insect as in ’ the man, the dominating principle of self-preservation, and the power that contends with him for a share of the natural, products of the world.