Pest (organism)

“ Occasionally, when his crops are destroyed by some insect-pest wonderfully adapted for its work, or when his cattle are infested with deadly parasites, or when some germ of disease is multiplying a million-fold in his own frame, he sees that all adaptations are not yoked to his especial service. ”

“ The egg-laying process may be repeated in a number of fruits and from each egg a larva hatches within a week and burrows to the stone, making a wormy fruit. Most of the infested fruits drop. Poisoning with an arsenate is the chief means of combating the pest. ”

“ Suffice to say, there is every prospect that the pest will continue to spread throughout the Eastern United States and Canada and that wherever it goes it will prove a direct pest to man as well as to his plants. ”

“ All are subject to the same disease and to the same treatment. The pest which commonly attacks wood is the little worm whose tracks may be found in all old pieces and whose living presence may be detected by the little particles of wood that drop from the hole in which the worm works. ”

“ After referring to the fact that poultry and all other domestic animals of ten suffer serious injury from the attacks of parasitic mites, and that even such household stores as sugar, flour, and cheese are not from their ravages, he tells of the discovery of a parasitic pest among bees. ”

“ They attack almost all kinds of animals as well as many birds, being of course a source of great annoyance and no inconsiderable loss. They are more apt to attack the feet of men, especially those who go barefooted. Sometimes [Pg 54] they occur in such numbers as to make great masses of sores.
On account of being such general feeders they are difficult to control, but some relief may be obtained by keeping the houses and barns as free as possible from dirt and rubbish and by sprinkling the breeding-places of the pest with pyrethrum powder or carbolic water. ”

“ A ladybird beetle, which has also been imported, is the most effective agent in keeping this pest in check.
Insects of the House or Storehouse.—Weevils are the greatest pests, frequently ruining tons of stored corn, wheat, and other cereals. Roaches will eat almost anything, even clothing; they are especially fond of all kinds of breadstuffs. The carpet beetle is a recognized foe of the housekeeper, the larvæ feeding upon all sorts of woolen material. The larvæ of the clothes moth do an immense amount of damage, especially to stored clothing. ”

“ But, however clear the evidence that fleas are the most important agent in the transfer of plague, it is a mistake fraught with danger to assume that they are the only factor in the spread of the disease. The causative organism is a bacillus and is not dependent upon any insect for the completion of its development. ”

“ When we observe, now, that different insects feed in two quite different ways, some by means of the biting type of mouth parts, and others by means of the sucking type, it becomes evident that we must know which kind of insect we are dealing with in the case of pests we may be trying to control. A biting and chewing insect can be killed by the mere expedient of putting poison on the out- side of its food, if it does not become aware of the poison and desist from eating it ”

“ Insects may carry the germs or parasites which cause disease in a purely mechanical or accidental way, that is, the insect may in the course of its wanderings or its feeding get some of the germs on or in its body and may by chance carry these to the food, or water, or directly to some person who may become infected. Thus the house-fly may carry the typhoid germs on its feet or in its body and distribute them in places where they may enter the human body. ”

“ Disease, in its most enlarged sense, is a conversion of one form of matter into another; it is a transformation of healthy blood and tissue into new and abnormal products. Where insects in all their variety of forms are discovered, their voracious propensities are their chief characteristics, they are the consumers of matter after its partial disintegration, if animal matter be their food, unless they be carnivorous and predacious, or if herbivorous they usually feed upon the tender shoots of plants. Thus far we are certain of the manner in which insects destroy living matter ”

“ Some Illustrations of Direct Inoculation of Disease Germs by Arthropods
In discussing poisonous arthropods, we have already emphasized that species which are of themselves innocuous to man, may occasionally introduce bacteria by their bite or sting and thus cause more or less severe secondary symptoms. That such cases should occur, is no more than is to be expected. The mouth-parts or the sting of the insect are not sterile and the chances of their carrying pyogenic organisms are always present. ”

“ The effect of the bite varies greatly with different species and depends upon the susceptibility of the individual bitten. Some persons are driven almost frantic by the attacks of the pests when their companions seem almost unconscious of any inconvenience. Usually, irritation and some degree of inflammation appear shortly following the bite. Not infrequently a hardened wheal or even a nodule forms, and sometimes scratching leads to secondary infection and serious results.
The source of the poison is usually supposed to be the salivary glands of the insect. ”

“ These miners are excessively harmful to plant-life, and form a class of the most destructive insect-pests known to the farmer: they frequently cause the death of the whole or part of the plant attacked. Now, we may suppose that the secretions of certain of these insects caused a swelling to appear where the larvae lived, and on this excrescence the larvae fed. It is easy to see that the greater the excrescence, and the greater the tendency of the larvae to feed upon it, instead of destroying the vital tissues, the smaller is the amount of harm to the plant. ”

“ Every lady gardener is troubled by insect pests—the horrid green canker-worm, the little green louse, the potato-bug; these are everywhere. One fights them with all sorts of powders and all sorts of syringes. ”

“ Fig. 353.—Pediculoides ventricosus. a, male; b, young female; c, gravid female. Enlarged. (After Laboulbène and Mégnin.)
These animals live on the stalks of cereals, and feed on vegetable and animal juices; they are also found on corn-infesting insects. They invade the barns and seek out the insects living in the dry grains of corn, or wait for an opportunity of obtaining food. They have been repeatedly observed on human beings, particularly labourers occupied in handling grain; their bite causes severe irritation, local elevation and reddening of the epidermis, as well as fever. ”

“ It is among the invertebrata, however, especially insects and worms, that the most striking agents of disease in plants are to be found, for, with the exception of certain rodents—and we may logically include also human invasions—vertebrate animals do not often appear in such numbers as to bring about the epidemics and scourges only too commonly caused by insect pests.
Insects injure plants in very various ways. ”

“ This is, however, not the only means whereby these insects can distribute deadly and other microbes, for it has been shown that in crawling over substances containing bacteria these may become attached to the feet of flies, and are in this manner transferred to other materials upon which they may alight, just as Pasteur showed many years earlier silkworms can communicate the fatal plague of pébrine by crawling over each other's bodies, carrying in their disease-laden feet the infection from one worm to another. ”

“ This type of insect gradually gave rise to the orders which now contain the largest number of species, including the beetles, moths, and flies. In many lines of this neuropteroid branch, as it is called, the larva has become adapted to a mode of life quite different from that of the adult. Many fly larvae, for example, live in rotting organic material or live as parasites within the tissues of other kinds of insects, whereas the adult flies often feed at flowers on pollen and nectar, visiting the site of the larval habitat only to lay eggs. ”

“ In like manner, the army worm may be defeated by burning up her eggs with the grass-stalks in which they are deposited. Or we may enlist in our service the natural enemies of the various insect-pests, such as birds, toads, snakes. But their greatest foes are "those of their own household," predaceous or cannibal and parasitic insects. The study of the habits of these insect allies and insect enemies of the husbandman is the occupation of the practical entomologist. ”

“ The silk-worm and the honey-bee have been in a measure domesticated, and rank with, though a long way after, our cattle, our animal pets and poultry. But wild insects! There is the turnip-fly, and the Hessian-fly, and botfly, and all sorts of worrying, and {112} blood-sucking, and disease-carrying flies, in and out of houses; and gnats and midges, and fleas in seaside lodgings, and wasps, and beetles, such as the cockchafer and blackbeetle—are not all these pests? ”

“ INSECT AND OTHER PESTS Vigorously growing plants are far less liable than are feeble ones to the attacks of the various living enemies which the gardener is called upon to combat. Therefore the most important item in the suppression of insect or fungoid pests is careful and correct culture. But, even in the best kept gardens, green-fly and earwig, slugs, snails and wireworms will appear, and must be dealt with by repressive as well as by preventive measures. ”

“ In the Blight of Trees we find, such Insects as are appointed to destroy a Cherry Tree, will not injure a Tree of another Kind, and again, unless the Leaves of some Trees are bruised by Hail, or otherwise Distemper’d, no Insect will invade them; so in Animals it may be, that by ill Diet the Habit of their Body may be so altered, that their very Breath may entice those poisonous Insects to follow their [Pg 18] way, ’till they can lodge themselves in the Stomach of the Animal, and thereby occasion Death. ”

“ Now, it is perfectly evident that if green muscardine spores could be produced in large quantity, or spores of similar disease-producing fungi, and applied to the ground and shrubs infested by insect-pests liable to harbor those fungi, we should have the best of all means for effecting the destruction of the insects, viz., a poison which once set at work would spontaneously multiply and spread its destroying agents around. ”

“ Many insects sting without poisoning the wound; the bite of the mosquito, black fly, flea, the bed bug, and other hemipterous insects, are simply punctured wounds, the saliva introduced being slightly irritant, and to a perfectly healthy constitution they are not poisonous, though they may grievously afflict some persons, causing the adjacent parts to swell, and in some weak constitutions induce severe sickness. ”

“ They are the most abundant of all organisms, their number of species exceeding that of all other animals, with all the species of plants taken together. Every terrestrial plant and animal has its insect-pests, and these in turn have insectean destroyers, which are indirectly friends to the animal or plant. ”

“ This insect falls down out of the air, and, if it happens to light upon any uncovered part of the human body, it almost instantly penetrates down469 to the bone, occasioning the most excruciating pain, and death in a quarter of an hour.171 Now, should we suppose the whole body of this insect to be poison, as it is probable that it is not, it is so minute, that though the whole were volatilized into contagion, it might be well supposed to adhere to a wig, or even a more diminutive part of the clothing ”

“ The minute size and great numbers of the bacteria make their dissemination a comparatively simple matter. They may be carried in the air as minute particles of dust; they may be carried in water or milk; they may be carried on the clothing or on the person from one host to another, or they may be disseminated in scores of other ways. In other chapters, particularly the one dealing with the house-fly and typhoid, we shall see how it is [Pg 19] that insects are often important factors in spreading some of the most dreaded of the bacterial diseases. ”

“ Many of the insect pests that infest the garden come to prey upon the plants indoors. The same warfare I wage without, I must wage within. Care and attention are ever the price of the flower. The insects continue to multiply. They develop new races and people new countries. No sooner does one scourge become extinct than a dozen others take its place. For the weevil we have the army-worm, the potato-bug, the apple-tree borer, the codling-moth. I no sooner administer a soporific to the red spider than the aphides are at work, and these are scarcely subjugated ere the mealy-bug appears. ”

“ Insect-pests are to be destroyed by poisoning them not with acrid mineral poisons which damage plants as well as the insects, but by encouraging the spread of the disease-producing bacteria which are known to be fatal to such insects. Professor Hagen, of Cambridge, Massachusetts, has called attention to the old practice of destroying greenhouse pests by the application of yeast. ”

“ Not only may such insects weaken the infested plants, but they also cause the destruction of chlorophyll, interfere with the normal functioning of the stomata, and have a toxic effect upon the tissues; further, many serious plant diseases are carried and spread by sucking insects, whilst the punctures made when feeding may allow the entry of disease spores. ”

“ The insect parasites and predators of other insects in general comprise a class of insects that are most beneficial to us by reason of their large-scale destruction of species injurious to our crops. But, unfortunately, parasites as a class do not respect our classification of other creatures into harmful and useful species. ”