ORDER LEPIDOPTERA.
The insects of this order are very numerous, and in their larval or caterpillar state they are often very destructive. In the perfect form of butterflies and moths, they commit little or no depredations, because their jaws have been transformed into a sucking apparatus. They consume, in their perfect state, little else than honey.
The order has been divided into three great sections: Butterflies,Papiliones; Hawk-moths,Sphinges; and Moths, orNocturnes. Of these, theÆgeridæconstitute a very distinct family, resembling bees and wasps rather than butterflies; their caterpillars also differ, being borers, and nearly naked. Butterflies are produced from caterpillars that are not generally very injurious to our crops. Hawk-moths are large insects, and have great power of flight; their caterpillars are large and voracious. It is the moths proper, a very numerous family, which do us the most harm, and which will demand the largest share of our attention. They vary much in size and appearance. Some of the females are destitute of wings.
TheArctiansor Woolly Bears, are a very numerous division of the tribe ofBombycesor Spinners, so called from the name of the Silk-worm; some of these will be mentioned.
Orgyia leucostigma, or the Vaporer Moth, is a very beautiful caterpillar, frequently seen upon our fruit trees, though not confined to them. They feed separately, and therefore we can best destroy them in the egg. Fortunately, these may easily be found during the winter, for the female, being wingless, never quits her cocoon, but deposits the eggs in a mass upon the outside of it. Thewhole contrivance is one of the many illustrations of the wonderful instinct of insects. When about to spin, the worm secures two or more leaves, by entwining her silk about their stems, and also around the woody twig upon which they grow; she then attaches them together by bands of silk, and spins her cocoon between them. She thus secures a winter resting place for her eggs, and her progeny, when they hatch the next summer, are upon the tree that furnishes them their appropriate food. These dead leaves will attract our attention during the winter, and should be gathered and burned. Many of the caterpillars are destroyed by a little Ichneumon-fly.
Orgyia antiqua, or the Rusty Vaporer Moth, of Europe, has been introduced into this country, and has been quite destructive to thorn-hedges in Rhode Island. They may become troublesome to our orchards.
Several of theseArctians, or Tiger-moths, may be seen about our houses on a summer evening, as they are chiefly nocturnal. One of the most common is
Arctia phalerata, or the Harnessed Moth, so called from the markings on its wings. Another distinctly marked one isCallimorpha militaris, now calledC. Lecontei. Beautiful illustrations of these are given in Dr. Harris' Report.
Spilosoma Virginica, is the beautiful White Moth, or "Miller," that we see in May; it is the imago or perfect insect of a large hairy caterpillar, of a yellowish color, frequently seen in our gardens, and quite destructive to vegetation.
Hyphantria textor, or the Fall Web-worm, is very troublesome upon shrubs and trees during the summer andfall. They are called the Web-worms from their habit of feeding gregariously in large numbers, and spinning a web that envelopes the leaves and the whole branch, as they devour the foliage.
This insect commits sad ravages upon our cultivated trees of various kinds, for it is not a choice feeder, consuming but one species, like many other insects. Their most common pasture is the mulberry, and the related Osage Orange is frequently attacked. The Elder bushes appear very attractive to them, and are often covered with their unsightly webs. Elms suffer very much; our favorite fruit trees are attacked; apples, pears, cherries, quinces, and, occasionally, even the peach trees are eaten by them. Even the repulsive Ailantus, which has often been recommended as a wormless tree, is greedily devoured by these caterpillars, notwithstanding its disagreeable odor.
The eggs, from two to three hundred in number, are deposited on the under side of a leaf, near the end of a twig. These soon hatch, and the larvæ commence feeding on the upper surface, spinning their threads from side to side, and then, attaching two or three leaves together, they soon make a web. They continue feeding and spinning along the twig, as they consume the tender portion of the leaf, leaving the mere skeleton.
The caterpillars are small, of a pale yellow color, with a broad blackish stripe on the back, and another beneath. They are thickly clothed with whitish hair; the head and feet are black. Worms of the same nest vary in size and colors. When about an inch long, they disperse, and spin their cocoons. The moth is milk white, without anymarkings on its wings, and is 1.25 to 1.35 inch in width. (Vide Harris, p. 358).
Though called the Fall Web-worm, these caterpillars appear about Cincinnati in the end of May quite abundantly, and from that time until October, they are more or less frequent; most so in August. In the North, they may be later; I have seen large tracts of forest defoliated on the lake shore, in August, 1865.
Remedies.—For the destruction of these pests we must resort to hand-picking, when they are in the caterpillar state. The twig or branch should be taken off, and the worms crushed or burned. It is fortunate for us that they are gregarious and that they spin a web, for we can detect them while they are yet young, and when confined to one or two leaves, so that the whole brood may be destroyed with very little effort. Birds, and some insects, aid us in keeping them in check.
Clisiocampa decipiens, (Walker), orC. Americana, (Harris), is commonly known as the Tent-caterpillar, or Nest-caterpillar. The larvæ are not indiscriminate feeders, but prefer the foliage of certain members of theRosaceousfamily of plants. Their natural food appears to be the common wild cherry, but they attack the apple so vigorously, that they are often called the apple tree worm. Mr. Fitch thinks they do not feed upon the peach; but I have frequently found them upon this tree since 1855. The moth appears to be endowed with wonderful instinct in depositing her eggs; selecting a terminal shoot that has completed its growth, they are placed to the number of 200 or 300 around it in a broad ring or sheath, and covered with a sort of varnish that protects them.
Very early in the spring, when the buds of the apple have just begun to swell, the eggs hatch, and the little worms traverse the twig, spinning a slender thread; when they reach another branch, they halt in the bifurcation, and, moving about, soon create a slight web with the silken threads, and from this they emerge in search of food, spinning a thread along their route, and when they return, they travel about, and thus enlarge their web.
Remedies.—These insects may be attacked in the egg or in the larval state. The former are so arranged as to be conspicuous on the naked spray at any time during the winter—whenever seen, they should be broken or cut off, and carried to the fire. In the early spring, we must watch for the little tents in the bifurcations of the limbs, and remove the nests with all the worms; this may be done when they are small, by using the thumb and finger; if larger, it is a disagreeable task, but no orchardist should hesitate when he recollects that six hundred leaves is a day's ration for one colony. They can easily be gathered in their web, thrown upon the ground, and crushed with the foot. Mr. Needham, of Massachusetts, has invented, what he calls, a caterpillar scourge; it is a little cone of wood, clothed with a piece of wool-card. This is attached to a pole: when thrust into the web, the whole nest is gathered by the card-teeth and brought down. An old dry mullein stalk has often been used for the same purpose, and some recommend burning the nest, or shooting it; but I have more faith in thumb and finger work, believing it to be more thorough.
Among the natural enemies of these caterpillars are the Tiger-beetles, which a successful orchardist of Illinoisuses systematically for their destruction. He catches a beetle, and puts it upon a tree containing a nest of the Tent-caterpillar, after which he finds the worms soon disappear.
Gastrophaca Americana, (Harris).—The Lappet-caterpillars are found on apple trees. The worms are flat, and when at rest on a limb, they often escape observation from their gray color resembling the bark. A fringe of hairs, along their sides, gives them this flat appearance. They feed only at night. Dr. Harris found some in September that measured two and one-half inches in length, and above half an inch in breadth.
SATURNIANS, CERATOCAMPIANS, ZEUZERIANS.
Platysamia (Attacus) cecropia, (Linn.), the Cecropia Emperor Moth, is found as a large cylindrical, pale green worm, three or four inches long, and as thick as one's thumb, and having two rows of pale blue, projecting points along each side, and two rows of pale yellow ones upon the back, with four larger, bright orange, or red ones anteriorly, all ending in little black prickles. The moth is large; its wings dark gray; each has a large white, crescent like spot in the centre, margined with red, and a red band crossing both wings. Appears in June; width five to seven inches.
There are others of this family of noble moths whose names have been indicated above, but they are not very destructive to the orchard.
Then come, in Dr. Harris' classification, theZeuzerians, a group of moths which, likeÆgeriansamong the Sphinges, pierce the roots and stems of trees. Among these isXyleutes (Cossus) robiniæ, or the Locust-tree Boring-moth.
The Saturnians are a group of large, naked caterpillars, which are generally short, thick, clumsy, and cylindrical; they are leaf eaters, and some of them, when young, keep together in families, but separate as they become older, when they spin large silky cocoons sometimes among leaves, which they secure by silk to the twigs, sometimes attaching them to the stems and limbs, and at others at, or beneath, the surface of the ground. This group contains some of the largest and most beautiful moths, with large woolly bodies, and widely extended, highly colored and ornamented wings. They lay a great many eggs; some females deposit several hundreds. Still they are seldom so numerous as to commit serious devastations.
"Among these are theTelea Polyphemus,Tropæ aluna,Callosamia Promethea,Platysamia cecropia, (formerly known under the genusAttacus, which is now restricted to the immenseA. Atlas, and another species of China), and theEuchronia Maia, andHyperchiria varia, (formerly known under the genusSaturnia, which is now retained for several European species). The latter species, (H. varia), has been generally known among us under the name ofSaturnia Io, but according to Dr. Packard, (who published 'a Synopsis of the Bombycidæ of the United States,' in the Third Volume of the Proceedings of the Entomological Society of Philadelphia), our species has been confounded by authors with Cramer's species 'Io,'from South America, and which belongs to a different genus."—[E.T. Cresson, Mss.]
These moths may yet become valuable for the production of a kind of silk, as they are enclosed in large cocoons, the fibres of which surpass those of the Silk-worm in strength, and might be employed in the formation of fabrics, similar to those manufactured in India from the Tusseh and Arrindy Silk-worms, the strength and durability of which are proverbial. Mr. Pullein, who experimented with the cocoons of theCecropiafound that twenty threads of this silk, twisted together, would sustain nearly an ounce more in weight than the same number of common silk.—(Vide Harris, pp. 295-303.)
Psychidæare curious caterpillars, which, being naked, cover themselves during the larva state with a case that protects their bodies, though open at both ends, and which they carry about with them; these cases are made up of fragments of leaves, generally the stems and veins, which they connect together by threads of silk. The Germans call them Sack-bearers. Huebner called themCanæphoræ, or Basket-carriers, because the cases, often made of little sticks, resemble a basket. One genus is calledŒceticus, or House-insect; and the common species, which, in some parts of the country, commits great devastation upon the leaves of trees, is called the Drop-worm, or the Basket-worm, in many places.
We have several genera and species belonging to this sub-family, the most common of which are theThyridopteryx ephemeraformis, andŒceticus coniferarum. The best means for the destruction of this pest consist in persevering efforts for their individual destruction; each caseshould be cut or torn off in the winter, when they show very plainly upon deciduous trees; they may be crushed, but had better be committed to the flames.
The Notodontians are so called from a hump or horn, which rises from the top of the fourth ring of the caterpillar; the tail is always raised when the insect is at rest. One of these is called, from its horn,Cœlodasys (Notodonta) unicornis. Some species consume the foliage of our fruit trees, particularly the apple and quince; one of these, theDatana ministra, (theEumetopona ministraof Fitch, or thePygæra ministraof Harris), will be noticed below.
Eudryas grata, andE. unio.—The Beautiful Wood-nymph, and the Pearl Wood-nymph.—The worms are very much alike, and resemble the Spotted Forrester. The moths come forth in July; the fore-wings are milk white, bordered behind and on the outer side, from the base to the middle, with rusty brown, edged on the inner side with greenish olive; hind-wings nankeen yellow, with a blackish-brown border. These worms are best removed by hand-picking.
Datana ministra, or the Hand-maid Moth.—The moths are troublesome visitors to the evening student in June; they are brown, hairy, thick-bodied, and measure rather more than an inch across the wings. This creature is destined to give us a great deal of trouble by her progeny, for she deposits her numerous eggs on the under side of the leaf on a twig of quince, apple, and cherry trees, where they hatch into worms, that, during their existence of about four weeks, consume immense quantities of foliage, often stripping the trees bare.
The worms feed gregariously, lying side by side in solid phalanx. They are of a dark brown in their younger state, but become lighter and more clearly marked at each successive moulting, so that they are distinctly striped with black and yellow. The peculiar character of this worm is, that when at rest, the head and tail are carried up in the air, or recurved over the body, which is supported by the six prop legs placed near the middle. When disturbed, these caterpillars often throw their heads from side to side, as though in anger. They are sparingly furnished with hairs, and they spin but little; though when young, the worms will sometimes drop from the leaves when disturbed, and hang suspended by a fine strand of silk. At full size, these creatures are an inch and three-quarters to two inches long, and as thick as a goose quill, so that we can readily imagine the amount of destruction which may be committed by one of these armies or family groups of one to two hundred worms.
Treatment.—Constant vigilance is required on the part of the orchardist, and unremitting efforts while the insect is in the larval condition. Fortunately for us, their habits are such as to aid us in a remarkable way. They may be looked for in July, but they become numerous only about the end of August, and in September. Some late broods may be seen on the access of early frosts, but by the end of September, the worms generally perfect their growth, and descend into the earth to undergo their changes for the next season, when the moths will again appear.
When we may be inspecting our orchards, in the summer and autumn, we should observe any defective foliage, as this is often an indication of the inroads of insects.If our trees have been neglected, we may be alarmed by observing some of the thriftiest shoots and branches quite stripped of their leaves; and, lying along the stems, or crowded together, we shall see these unpleasant worms, unless they be foraging upon an adjoining, or sometimes upon quite a distant branch; for, in changing their pasture, they descend one twig and pass out upon another, which may diverge considerably from the first.
In the early stages of their existence, however, the little worms consume only the upper surface of the leaves, and it is at this period that we may most advantageously attack them. The leaves that have thus had their substance eroded become dry and whitish, and attract our attention. They are generally found upon a single twig or spray, usually a lateral, and it should at once be examined, as we may now easily destroy the whole brood by rolling a single leaf between the thumb and finger.
NOCTUÆ, OR OWLET-MOTHS, CUT-WORMS.
The perfect insects are thick-bodied, and of dull colors; they fly at night. The caterpillars are naked, live in the soil, and feed above ground at night, when they do considerable damage. The common Cut-worm,Agrotis, is an illustration. There are several sorts, which have received different names, but the worms all have very similar habits.
The moths are supposed to lay their eggs in July, when they soon hatch and feed during the season; they attain considerable size and hybernate in the soil.
Remedies.—Fall and winter plowing has beenrecommended, as it exposes the worms to the birds, and to the weather, but especially because it destroys the vegetation upon which they might subsist in the early spring. The only safe way, is to watch their traces among our plants, and dig down beside them, find the worm, and destroy it. Though this does not restore the plant already killed, we prevent further damage, and may hope to thus diminish the pest in future years, which is no small matter. A knowledge of their nocturnal habits has induced some gardeners to go among their young plants with a lamp or candle at night, when they may find the caterpillars feeding. A few choice plants may be protected by wrapping their stems with a strip of paper, or a stout leaf, (hickory), at the time of transplanting into infested grounds; this will save them. Tobacco water has been found very effective, applied to the plants, which it does not injure.
Mamestra arctica, (Hadena amica, of Harris, andH. amputatrix, of Fitch), is a Cut-worm of a brownish color, about one and a half inch long. It is sometimes quite destructive in the nursery and garden, ascending woody plants, and cutting them off where succulent, in the month of May. It can only be checked by seeking for it, in the soil, near the base of the plants affected.
All these Cut-worms are eaten by birds, among which the crow is a valuable aid to the farmer, and should be cherished for his services instead of being condemned as a bird of ill-omen. Predacious insects also consume numbers of them; one of these is the larva of a beetle,Harpalus calaginosus. A large Ichneumon-fly has been found hunting after the worms, and is considered their natural enemy.
GEOMETERS, SPAN-WORMS, CANKER-WORMS.
The measuring worms take their name from their peculiar method of locomotion; having their legs at each end of their long bodies, they walk by progressive leaps, arching up their backs by bringing their hind-legs forward, and then thrusting their heads out to their full length. Many of them drop from the trees, and hang suspended by a thread of silk, when disturbed, or when seeking the earth to undergo their transformations. Some of them are naked, or have few hairs; most are smooth, often striped, or of an uniform color, like the bark of the trees on which they feed.
The moths are slender-bodied; the wings large; of some the females have no wings. These are theHybernians, including the Canker-worm,Anisopterix vernata. These caterpillars are very numerous and destructive; they do not feed gregariously, and are difficult to combat in that form. The pupæ are under ground, and, as the female moths are wingless, and must ascend the trees to deposit their eggs, we can destroy them in the perfect form by meeting them on the highway they have to pass. Ingenious devices have been invented for this purpose; among the most effective of these are vessels of oil, fastened closely around the bole of the tree. The moths emerge from the ground in early spring, but many come out during pleasant mild days in the winter, and some even in the autumn; so the remedies must be applied early to be of any use.
Harris describes a smaller species as theAnisopterix pometaria.
Hybernia tiliaria, or the Span-worm of the Linden, isabundant in June, growing to the length of an inch and a half. A belt of tar, applied to the trees, has been found effective in preventing the ascent of the wingless females; this needs renewing daily, until the season of their rising has passed.
Ellopia ribearia, or the Currant-moth, was figured and described by Fitch as theAbraxas? ribearia, in New York Reports for 1856. The worm is light yellow, with black dots. It eats the leaves of currants and gooseberries, in June. The moth ascends from the ground in July; it is nankeen-yellow; quite a common insect in some parts of the country. It must have some natural enemies, for, where very abundant one year, it sometimes disappears altogether the next. Hand-picking is the only remedy known, and this is quite a tedious process.
TORTRICES, DELTA MOTHS, OR LEAF-ROLLERS.
The Leaf-rollers are a numerous tribe, and some of them are troublesome upon our cultivated trees and vines. They curl up the edge of the leaf upon which they feed, and fasten it with little bands of silk, and thus shelter themselves from the weather and from their enemies. They are naked worms, and generally light colored, and exceedingly active. Some live in the unfolding leaves and flower-buds, fastening them together so they cannot expand, while they devour the tender tissues. Some enter the young fruit, which they cause to ripen and fall prematurely. The moths are generally small, often prettily marked, and fly only in the evening.
Loxotænia rosaceana, (Harris), is found soon after the buds of the apple begin to expand. They curl up and fasten them together, and do considerable damage.
Penthina oculana, (Harris), has similar habits, and preys upon the apple; both must be killed by hand.
Brachytœnia melania, or the Many-dotted Apple Leaf-worm, is mentioned by Fitch[40]as eating holes in the leaves, in June and September. It is rather thick, light green, an inch and a quarter long, with five white lines and numerous white dots; the worms spin their cocoons in a leaf. There are two crops.
Loxotænia cerasivorana, (Fitch), or the Cherry Tortrix, is a deep yellow worm, with black head and feet. Found in July, fastening the leaves together and living in families, forming a large nest.[41]
Desmia maculalis, or the Spotted-winged Sable, or Grape Leaf-folder, is a slender, active green worm, that feeds upon and disfigures the leaves of our grape vines, rolling them with great regularity, and fastening them with strong bands of beautiful white silk. The pupa is formed within the rolled leaf. These worms begin in June, but continue to fold the leaves during the season of growth.
They can be destroyed by hand-picking, but it requires quickness and dexterity, as the worm escapes from either end of the open pipe when disturbed. The warblers are very fond of them, and destroy a great many.
Carpocapsa pomonella, or the Codling-moth, is one of these Tortrices, which gives great trouble. It has beenintroduced from Europe, but is steadily increasing as our orchards grow older, until we now have few perfect fruit. The moth appears early in the summer to lay the eggs of the first crop of worms. This insect is figured and described by different authors, among whom Dr. Trimble, of New Jersey, has paid it especial attention in his recent work.
The eggs are dropped singly upon the blossom end of the apple, that affords an entrance to the young worm, which passes to the core, about which it consumes the pulp and the seeds. The worm is whitish, becoming flesh-colored. In warm weather it attains its growth in three or four weeks, and makes its exit by gnawing through the side of the fruit. It instinctively seeks the stem of the tree to secrete itself under the scales of bark, and this affords us an opportunity to destroy it in the pupa state, for it will creep under any shelter that may be put in its way.
TheRemedieswill depend upon the habits of the insect. The moth, being nocturnal, may be destroyed by burning lamps or fires in the orchard during June, when they are first at work; cheap coal-oil may be used for the purpose. The pupæ can be entrapped in large numbers, by putting a piece of old rag in the crotch of the tree, beneath which the worms will crawl to spin their cocoons, when they may easily be destroyed. Dr. Trimble has used a trap, made by twisting a hay rope and fastening it about the trunk of the tree; under the rope immense numbers will be found. This trap should be examined fortnightly, as the moths hatch out during hot weather in a shorter time than later in the season, when some remain over winter in the pupal state.
All wormy fruit should be gathered as soon as it fallsfrom the trees, and either be boiled, or at once fed to swine. Hogs and sheep, kept in the orchard, will generally consume the fruit as fast as they fall to the ground; and this is the simplest and cheapest method of destroying the worms.
Chætochilus pometellus, (Harris), is commonly called the Palmer-worm. It feeds upon the leaves of our orchard and forest trees in June. Sometimes it appears in immense numbers, and, coming after the period for the production of new leaves, great damage is done to the trees; old trees, and limbs of younger ones, are sometimes killed. There have been two celebrated invasions of this insect in the Eastern States, those of 1791 and of 1853.[42]
GRAPE VINE FEEDERS.
Grape vines are subject to the attacks of many lepidopterous insects. Dr. Harris gives the history of seven American larvæ, mostly of large moths, which feed upon grape leaves.
Pterophorus periscelidactylus, or the Gartered Grape vine Plume, is a pale green worm, half an inch long, which hides itself in a hollow ball of leaves, fastened together with silken threads. It is described at length by Dr. Fitch, in the New York Agricultural Transactions.
Ohis myron, (Chærocampa pampinatrix, ofHarris), called also the Vine Dresser, is somewhat troublesome in the vineyards, as it eats the leaves, and cuts off the bunchesof grapes when half grown. This worm is thick, cylindrical, tapering anteriorly, pale green, freckled with pale yellow dots, and, when mature, a pale dusky olive; 2.25 inches long. The pupa is found under leaves on the ground; the moth emerges in June.
Philampelus satellita, andP. Achemon, the Satellite and Achemon Sphinges, are large green worms that feed upon the vine. They bury themselves in the ground when going into the pupa state, and remain until the next July. The worms are seen in August and September.
Procris Americana, or the American Forrester, is found feeding upon the grape leaves at mid-summer, (June 22). The worms feed gregariously on the surface of a leaf, some twenty side by side, leaving only a skeleton behind them when small, and consuming the leaf when older. They are small, 0.60 inch long; yellowish. The moth is blue-black, with a bright orange neck.
Alypia 8-maculata, or the Eight-spotted Forrester, is a light blue worm, 1.25 inches in length. They leave the vines in July, and spin a web on the ground; the moth appears in May; it is black, with orange shanks; each of the fore-wings has two large, light yellow spots; the hind-wings have two white ones. Width 1, to 1.50 inch.
ÆGERIANS.
Ægeria exitiosa, (Say), orTrochilium exitiosum, is well known in its larval state as the Peach tree Borer, and is often so destructive as to kill the trees. The habits ofthe worm as a borer, and its situation at the base of the tree, are somewhat similar to those of the apple tree borer; but while that is the footless grub of a beetle, this is a true caterpillar, the larva of a butterfly or moth, with feet. The females deposit their eggs from June to October, placing them upon the bark at the surface of the ground, sometimes in the forks of the large limbs. The larva enters, and works downward; first consuming the bark, but afterwards eroding the wood also. Gum exudes from the wound, mixed with their castings, and indicates their presence. When ready to enter the pupa form, the worms come to the surface, excavate a hollow in the wood, and prepare a tough leathery follicle or pod, three-fourths of an inch long, in which they repose as pupæ.
This, or an analagous insect, attacks the plum tree, and behaves in a similar manner. The double-flowering Almond of our shrubberies is also attacked by the borer.
The perfect insect looks more like a wasp than a butterfly, for the wings of all this group are partially clear of feathers, and transparent. It varies in size from a half to three-quarters of an inch in length, and from eight-tenths to one and three-tenths of an inch across. The female varies more than the male, and her wings are larger in proportion to the body, which is heavier. The male is of a deep steel-blue color, with sulphur-yellow marks, and glossy luster. The wings are transparent and glossy; the veins margined and fringed steel-blue.
Remedieswill depend upon the habits of the insect, and must be directed to the pupa and larva, though valuable preventives are applicable to the perfect insect. The worms may be sought out by scraping away the gum andcutting the dead bark until we find them, often along the main roots; the follicles with the pupæ should also be sought. This work can be done in the autumn and spring; if at the former season, the removed earth should be left away from the stem, when coal tar may be applied to destroy any worms left in the tree and to act as a preventive against future attacks, but this substance should be used with great caution. If applied, the earth should be thrown back to the tree. Boiling soap-suds has been used with good effects.
Preventivesare sometimes better than cures, and in this case they have been very successfully used. They all consist in means to keep the moth from depositing her eggs in the part of the tree where, alone, the borers can be harmful. Some raise a little mound of earth about the tree in the spring, and allow it to remain there all summer. The first application of this principle consisted in placing a chimney crock about the base of the young tree when planted; into this coal ashes, cinders, or even gravel was placed, which protected the base of the tree. In the autumn the crock was lifted, and the materials scattered. An open box, made of four bits of board, tacked together, answered the same purpose. A cone of coarse brown paper, tied about the tree with grocers' string, or pasted upon the tree itself, when applied, will answer a very good purpose in keeping off the fly.
A small portion of sulphur thrown about the tree is said to have the desired effect, but the statement has not been confirmed by trial. It has been recommended to plant Tansy with every peach tree, but doubt attaches itself to this suggestion also.
In theAmerican Agriculturist, for February, 1865, is a notice of a peach tree protector made of sheet-iron, like a stove-pipe; and in the April number, Mr. Bouthorpe, of Massachusetts, says, he had used a similar apparatus made of zinc, eight inches long, and twice the size of the tree, which was of easy application; the contained space next the tree was to be filled with loose dirt. They were found to be a perfect protection.
Ægeria tipuliformis, (Linn.), or the Currant Borer, has been imported from Europe. The eggs are laid near a bud; when hatched, the worms penetrate the pith of young shoots, killing them.
Ægeria pyriis mentioned by Dr. Harris[43]as having done a good deal of damage to pear trees, by boring under the bark. The perfect insect resembles that of the Currant Borer, and makes its appearance near the end of summer, leaving its chrysalis skin projecting from the hole in the bark, whence it had escaped.
Ægeria polistæformis, or Grape Vine Borer, is mentioned by Mr. Glover in the Patent Office Report for 1854, p. 80. He had received it from North Carolina, where it was very destructive to all vines, except the Scuppernong. This insect has become rather common in the vineyards about Cincinnati, and its depredations, in consequence of the large size of the caterpillar, are very serious. The eggs are laid near the roots of the vine, and the larvæ bore into the bark and wood during the summer, consuming them so completely, that the vine sickens and dies, and often breaks off at the ground, or just below the surface. When fully grown, they measurefrom an inch to an inch and three-quarters in length, are thick and whitish, and they form a pod-like chrysalis, similar to that of the Peach Tree Borer, but within or beside the injured roots.
The moths are of a dark brown color, tinged with tawny-orange, and banded with bright yellow on the edge of the second ring of the body; the fore-wings are dusky, and the hind ones transparent.
Remedies.—No effectual methods of prevention are known; but it is well to inspect the vines, and when the presence of the insects is suspected, examine the roots, to find and destroy the worms.
NEUROPTERA, HYMENOPTERA, AND DIPTERA.
These several orders will be introduced together for convenience, as they may be disposed of in a briefer mention than some of their predecessors; because they do not contain so many species that are noxious by preying upon our cultivated plants. Some are even of advantage to us by their carnivorous propensities.
Among theNeuropteraare several which are aquatic in their larval condition, but when winged, they devour many insects; among these are the Dragon-flies, commonly called Devil's-needles by the children, who dread them, but they are harmless creatures. The Ant-lions were referred to under the head of Aphids, in the consideration of the orderHemiptera, as most voracious destroyers of Plant-lice. Reference was also made to the Lace-winged Flies,Hemerobius, which, in the larval state, consumeimmense numbers of the same pests. A few of these insects are injurious; among them are the White-ants, Wood-lice, and the Wood-ticks, which are annoying, though they do not affect our crops.
Of theHymenopterathere are many which, in a perfect state, consume the juices of our choice fruits, as well as the pollen and honey of flowers. Their services among these last, as aids in fertilizing the germs, is often of great importance to the fruit-grower. But, while acknowledging our gratitude to many for this service, and to the industrious bee for gathering abundant stores of the nectared sweets, we have a serious charge to bring against the family for their depredations. The wasps especially are often troublesome, particularly in the vineyard, and their stings are annoying. Some ants are quite injurious.
The larvæ of some species are destructive as wood borers and as leaf-eaters, and others cause an excrescence or warty growth upon the twigs and leaves where the eggs have been deposited; these are calledGall-flies. The great benefits rendered by a very large class of insects in this order, however, may compensate for all the evil done by the others. I refer to the tribe ofIchneumon-fliesof several genera. Some of these are very small, and deposit their eggs within other insects, where they hatch and destroy them by feeding upon their juices.
Many of the wasps are predaceous, and destroy numerous insects to feed their larvæ. Some of these exercise a wonderful instinct in preparing and securing this food for their young, which is stored up in safe caskets with the egg, and are ready to serve as food to the young larvæ.
TheDiptera, or two-winged insects, form an extensiveorder, containing many species, and these are composed of very numerous individuals. Flies and mosquitos are exceedingly annoying to man and animals, and many species, in the larval state, consume vegetable matters; but even here they are often of use in consuming decayed vegetation, and like many others of the order may be considered scavengers, consuming, as they do, immense quantities of filth and carrion, that would otherwise continue to taint the air and produce disease.
Some of the most destructive insects of this order are theGall-gnats, among which are the Wheat-fly and the Hessian-fly, which often sadly interfere with the farmer's prospects.
A few insects will now be noticed more in detail.
Selandria cerasi, orBlennocampa cerasi, is the common Slug of the cherry and pear trees, and quite a troublesome hymenopterous insect. In some parts of the United States these little creatures are so numerous as to strip the substance from the foliage of pears and cherries.
Our Slug resembles theSelandria œthiopsof Europe, but is declared to be different. The larvæ are at first white, but the slimy substance that oozes from their bodies covers them with an olive coating. They have twenty very short legs; when fully grown, the largest are about nineteen-twentieths of an inch long. The head is concealed under the fore part of the body, which is largest before, and tapers behind. They attain their growth in twenty days, casting their skins five times, eating them until the last time, after which they remain free from viscidity, and are of a clear yellow color. They leave the tree and enter the ground to the depth of one or threeinches, to form their chrysalids. In three days they come up as flies, in July and August, to lay eggs for a second brood, the pupæ of which remain in the ground during the winter.
Another insect of this genus is very destructive to our rose bushes; it is calledSelandria rosæ.
Selandria vitis, is a species that appears upon our grape vines, and is quite troublesome in some vineyards in July. They feed in companies of a dozen or more.
Remedies.—Shaking them off the leaves has been recommended, but does not promise to be effectual. When few, they should be sought for and crushed, to prevent their increase. Though troublesome, this may be effectually done, and their ravages leave traces that will direct us to the leaves which contain them.
When more numerous, the foliage may be syringed with common soapsuds, or with the whale oil soap, two pounds to fifteen gallons of water.
Air-slaked lime has been dusted upon them with good effect; ashes, and even dry dust from the road, will destroy them, by adhering to the slimy surface. These applications are best made when the foliage is wet after a shower, or with the dew. The great difficulty consists in their habit of going under the leaves, and thus being protected.
Mr. Parkman, the noted rose fancier, has found a mixture of soap and petroleum of great service, as it kills the slugs without injuring the buds and foliage. To a gallon of soft soap he adds two-thirds of a pint of petroleum, mixes them thoroughly, and dissolves in half a barrel of water; to be applied with a syringe.
Diptera.—Dr. Fitch describes as a new speciesMalobrus mali. He found them in a fruit that had been perforated by the Codling-moth. The larvæ are transparent; the flies resemble the Hessian-fly, that destroys the wheat plant.[44]
Cecidomyia grossulariæ, or Gooseberry Midge, attacks the fruit, giving it the appearance of ripening prematurely. Considerable fruit is lost in this way.[45]
In closing this chapter, the author feels obliged to express his regrets that no more space could have been appropriated to this important subject. He could only indicate some of the most troublesome insects of our orchards and vineyards, and he hopes that the reader will be induced to pursue the investigation for himself. He knows, by experience, that the study will bring its own reward in the information that is received, and which is absolutely necessary to enable us to combat these troublesome pests successfully.