Chapter III: Cherry Culture (2)

Cherry trees in the past have been headed three or four feet above the ground but in new plantations they are now usually started lower--at half of the above distances. Two forms of top are in vogue, the spire-shape and the vase-shape. Sour Cherries are almost universally grown with closed centers but some growers prefer the form of the vase for Sweet varieties, though the majority hold to trees with central trunks and many subsidiary branches. Little pruning is done in cherry orchards after the first two or three years, by which time the sapling has been shaped. Subsequent pruning consists in removing dead, injured or crowded branches and an occasional superfluous one. Heading-in finds little favor with experienced growers. These few statements indicate that the cherry, as now grown, is pruned but little, and that that little must be done very carefully, the pruning knife in the hands of a careless man being, with this fruit, "a sword in the hands of a child."

The general tuning-up in the cultivation of fruits during the past quarter-century has had its influence on cherry culture. Commercial orchards are no longer kept in sod and the clean, purposeful cultivation that has taken the place of grass has doubled the output of cherries, tree for tree, throughout the State, the difference in yield being especially noticeable in seasons when drought lies heavy on the land. Cultivation, as practiced by the best growers, consists of plowing the land in the spring and then frequently stirring the soil until the first of August, at which time a cover-crop is sown. If the soil is light, and therefore hungry and thirsty, the plowing should be done early and the cultivator kept constantly at work until cherry-picking. Cherry orchards often, without apparent cause, have an indefinable air of malaise--look dingy and unhappy--such require almost week-to-week cultivation to tide them over their period of indisposition.

Grain, as well as grass, is discountenanced in cherry orchards, but cultivated truck and farm crops in young plantations, or, under some conditions, small fruits, are looked upon as permissible and often pay for the keep of the young trees until they come into profitable bearing. Cover-crops are in common vogue in cherry orchards in New York and, since with this fruit they can be sown earlier in the season, are used to better advantage than in other orchards to furnish a full supply of humus and to provide nitrogen. Brown-rot, an annual scourge in most cherry orchards, takes less toll from trees cultivated and cover-cropped, these operations covering the mummied fruits and keeping the spores they carry from coming to light and life.

Cherry growers as a rule are not now using fertilizers for their crops. It would seem that this is not doing duty by the land; but it must be remembered that the cherry grows vigorously and that over-feeding may stimulate the growth too much, laying the orchard open not only to unfruitfulness but to winter injury of bud and tree. Among those who use fertilizers there is little accord as to what fertilizing compounds are best or as to what the results have been. There is common agreement, however, that Sour Cherries respond more generally to fertilizers than the Sweet sorts. Until there are carefully carried out fertilizer experiments with this fruit the vexatious problems of fertilization cannot be solved. Nitrate of soda seems to be a great rejuvenator in orchards laid down to grass. Whatever the cause, when leaves lack color and hang limp, this fertilizer is a sovereign tonic. Heavy dressings of stable manure are much used in grassed-over orchards, as they are, also, in such as have had none or but scant crops.

THE COMMERCIAL STATUS OF CHERRY-GROWING IN NEW YORK

Cherry growing is a specialist's business in which, under the best of conditions, there are more ups and downs than with other fruits. Because of the great profits that have come to a few in the years just past many growers have been drawn into the business in a small way or have planted an acreage beyond their means to manage. The inevitable depression that follows over-planting is, at this writing, at hand and spells ruin to some and disgust and discouragement in the industry to others. Perhaps no fruit can better be left to men of reserve capital than the cherry, and even with men of substance cherry-growing should largely be incidental to the culture of other fruits--an industry to fit in to keep land, labor and machinery employed.

Cherry trees begin to bear in the climate of New York when set from three to five years. The varieties of _Prunus cerasus_ first produce profitable crops but, at from six to eight years from setting, both Sweet and Sour sorts are in full swing as money-making crops. The limits of profitable age are not set by the life of the tree but, rather, by its size. Thus, cherry trees of either of the species commonly cultivated are not infrequently centenarians but the profitable age of an orchard is not often more than from thirty to forty years. After this time the trees become large and the expense of caring for them and of picking the fruit becomes so great as to prevent profits. Moreover, disease, injuries and inevitable accidents will have thinned the ranks of trees until the orchard is below profit-making.

Cherry-picking begins in New York about the first of July, following the rush in harvesting strawberries, and lasts, if the orchard contains both Sweet and Sour varieties, from four to six weeks. Workers may in this way fill in a gap between small-fruits and other tree-fruits and the crop becomes one in which the grower may often take small profits to keep his help employed; though, in the long run, if the more or less frequent depressions can be weathered, the cherry may prove as profitable as other fruits.

The problem of labor is a most vexatious one under present conditions, it being impossible to obtain casual men laborers for cherry-picking and women and children are unsatisfactory, since the fruit must be carefully picked or both cherries and trees suffer. The problem is solved, unsatisfactorily in most cases, in various ways by different growers. Most of the crop is now picked by children in the teens under the eyes of men or women supervisors. In picking for the market the stem is left on and only the stem is touched by the fingers. Cherries for canning factories are less laboriously picked. The picking package is usually an eight-pound basket. The rate paid is one cent per pound. Pickers earn $1.50 to $2.00 per day in good seasons. Close watch is kept on pickers to prevent the breaking off of fruit-spurs, thereby destroying the succeeding year's crop, varieties fruiting in clusters suffering especially from carelessness in this respect. Cherries are picked a few days before full ripeness.

Cherries are sent to canneries in various packages but chiefly in half-bushel baskets or paper-lined bushel crates, the container being often supplied by the cannery. The six- and eight-pound baskets are the favored receptacles for Sour Cherries in city markets but the Sweet sorts are rather oftener sent in four-pound baskets and still more frequently in quart boxes. In the larger packages not much effort is made to make the fruit attractive but in the smaller ones, stemless and bruised cherries are thrown out and the package filled, stem down, with the best fruits. In fancy grades all of the fruit in the box is layered. The demands of the market, of course, determine the package and the manner of packing. Cherries are seldom stored longer than a few days at most in common storage and a week or two weeks in cold storage.

There is a marked difference in the shipping and keeping qualities of varieties of cherries, the sorts that keep longest and ship best, quite at the expense of quality, having the call of the markets. Undoubtedly this must remain so, though it is to be desired that local markets, at least, be supplied with the best, irrespective of handling qualities. A further factor that prevents the placing of choicely good cherries in distant markets at all times is brown-rot, to be discussed later, which more often attacks the juicy and usually the best-flavored varieties, oftentimes ruining the pack on the way to market--one of the most discouraging events incidental to cherry-growing.

Marketing machinery for cherries is at present very costly, inadequate and frequently sadly out of gear. The fruit passes first from the grower to a local buyer who ships to a center of consumption, transportation companies taking heavy toll on the way. Jobbers or commission companies, who in some cases receive the fruit direct from the grower, then distribute the crop to retailers in the consuming centers. Lastly, the retailer parcels out the quantities and the qualities demanded by the housewife. The whole business of selling the crop is speculative and the grower is fortunate to receive half of what the consumer pays and not infrequently has all of his pains for nothing or may even be forced to dip into his pocket for transportation. The perishableness of the product and the present defects of distribution go far to make the crop the hazardous one it is but all look forward to better times coming under an improved system of marketing.

Up to the present, it must be said, but little effort has been made in New York to ship far and to develop a trade in cherries other than at the canneries. The canners have until the last year or two taken the cream of the crop but with recent greatly increased plantings are now over-supplied. The average grower, possessing a mixture of mental inertia and business caution, has not sought other sources for the surplus fruit. Bolder and more energetic spirits are now developing new markets and opening up those to which other tree-fruits more generally go so that the present over-production may prove a blessing in disguise. The greatly increased demand, for Sour Cherries in particular, brought about by the development of markets in 1913-14, are most hopeful signs for the future of the cherry industry.

CHERRY DISEASES

Cherries, without preventive or remedial intervention, are at the mercy of two or three fungus diseases and sometimes several others are virulent, depending upon locality, season, weather and variety. One of these diseases, brown-rot, in spite of the great advances in plant pathology of recent years, is almost beyond the control of preventive or remedial measures. Happily, all the others yield better to treatment.

Brown-rot[55] (_Sclerotinia fructigena_ (Persoon) Schroeter), sometimes known as fruit-mold or ripe-rot, very frequently attacks flowers and shoots but is most conspicuous on the ripe or ripening cherries where its presence is quickly detected by a dark discoloration of the skin which is afterwards partly or wholly covered with pustule-like aggregations of gray spores. The decayed fruits usually fall to the ground but sometimes hang to the tree, becoming shriveled mummies, each mummy being a storehouse of fungus threads and spores from which infestation spreads to the next crop. The disease, in some seasons, like a withering blight, attacks twigs, flowers and leaves early in the spring doing great damage to the young growth and often wholly preventing the setting of fruit. The rot spreads with surprising rapidity on the fruits in warm, damp weather either before the fruit is picked or in baskets while being shipped or stored. Preventive remedies have so far met with but indifferent success; probably the best method of control is to destroy the mummy-like fruits and all other sources of infection either by picking them from the trees, or much better by plowing them under deeply. Varieties of cherries show various degrees of susceptibility to brown-rot. All Sweet Cherries are more subject to the disease than the Sour sorts. But with either of the two species there are great variations in the susceptibility of the varietal hosts--a matter specially noted in a later chapter in the discussion of varieties.

Another serious disease of the cherry, and probably the most striking one in appearance, is the black-knot[56] (_Plowrightia morbosa_ (Schweinitz) Saccardo), characterized by wart-like excrescences on shoots and branches. Black-knot looks more like the work of an insect than a fungus and was long supposed to be such even by those who were studying the trouble. The knots begin to form early in the summer and are of characteristic color and texture--dark green, soft and velvety, but in the fall, as the fungus ripens, the color changes to coal-black and the knots become hard and more or less brittle. The excrescences usually form on one side of a twig or branch so that death seldom follows quickly. The disease attacks both wild and cultivated plants in every part of this continent where cherries are grown but is epidemic only in the East, the cherry regions of the West being practically free from the disease. Up to the present time the fungus has not been found elsewhere than in America. Happily, black-knot may be controlled by cutting out the diseased wood. To completely eradicate the fungus, if it is especially virulent, however, the orchard must be gone over several times during a season. In New York the removal of black-knot is ordered by law, the results showing that when the law is obeyed, especially if there be hearty co-operation among growers, eradication is usually possible. Sweet Cherries are much less attacked by black-knot than the Sour sorts but the differences in immunity between varieties in either of the two species are not very marked--at least such is the case on the grounds of this Station where the disease is always present and is often very prevalent.

_Exoascus cerasi_ Fuckel[57] is the cause of a very striking deformity of the cherry in Europe, both _Prunus avium_ and _Prunus cerasus_ being attacked. The disease has been reported in America but has not yet become virulent. The fungus attacks the branches, causing a clustering of the twigs in the form of a broom, giving it the name witches' broom. The leaves on the diseased twigs usually take on a crinkled shape and a reddish color. The malady may be readily prevented by the destruction of affected branches.

In common with other species of Prunus the foliage of cherries is attacked by several fungi which produce diseased spots on the leaves, the dead areas usually dropping out leaving holes as if punctured by shot. Thus we have "shot-hole fungus," "leaf-spot" and "leaf-blight" as effects of these diseases. Three fungi are in the main responsible for these leaf troubles; these are _Cylindrosporium padi_ Karsten,[58] _Mycosphærella cerasella_ Aderhold[59] and _Cercospora circumscissa_[60] Saccardo. The ravages of these fungi are prevented by the proper use of bordeaux mixture and lime and sulphur, remedies which, however, must be used with some care to avoid spray injury. With these, as with other fungi, cultivation has a salutary effect as it destroys diseased leaves which harbor the fungi during their resting period.

Cherry leaves are often covered with a grayish powder which in severe cases causes them to curl and crinkle and sometimes to drop. This powdery substance consists of the spore-bearing organs of a mildew[61] (_Podosphæra oxyacanthæ_ De Bary). Powdery mildew is much more common on nursery stock than on fruiting trees and in New York is a serious pest on young cherry trees. In the nursery, injury may be prevented by the use of copper sprays or lime and sulphur, either of which is also an efficient preventive in the orchard but the mildew is seldom prevalent enough on orchard plants to require treatment.

Wherever cherries are grown in either the nursery or orchard, crown gall[62] (_Bacterium tumefaciens_ Smith and Townsend) has obtained a footing. In the North at least, it seldom greatly injures old trees, but if the galls girdle a nursery plant serious injury results. Therefore, badly infected young trees showing galls should not be planted. However, but little harm is liable to result under most conditions. When infected plants have been planted it has been found that galls vary greatly in duration, sometimes disappearing within a year or two and at other times persisting indefinitely. The tumor-like structures are usually at the collar of the plant and vary from the size of a pea to that of a man's fist, forming at maturity rough, knotty, dark-colored masses. Neither prevention nor cure has been discovered, though it is known that soils may be inoculated with the disease from infected stock and that, therefore, diseased trees should not be planted in soils virgin to the galls. It is probable that there are differences in the susceptibility of Sweet and Sour cherries to the fungus and that the varieties of the two species vary in their resistance but as yet no one seems to have reported on the differences in susceptibility of cherries to the disease.

The leaf-rust[63] (_Puccinia pruni-spinosæ_ Persoon) of stone-fruits, occurring rarely on the fruit, sometimes attacks cultivated cherries and is a rather common disease of the wild _Prunus serotina_. This rust is troublesome only, however, in warm, moist climates. It is most apparent in the fall and is easily recognized through its numerous rust-colored sori on the underside of the leaves. Defoliation takes place in severe infestations. Either bordeaux mixture or lime and sulphur may be used as a preventive.

Old cherry trees are often attacked by a fleshy fungus or "toadstool"[64] (_Polyporus sulphureus_ (Bulliard) Fries). This fungus is said to be world-wide in its distribution and to occur upon a large variety of trees. It is very striking in appearance, the clusters appearing during late summer or early autumn in large, shelving branches, the sporophores fleshy and of cheese-like consistency when young but becoming hard and woody with age. At first the "toadstools" are all yellow but later only the under surfaces are yellow while the upper surface is orange-red. The plants are more or less odoriferous, the odor increasing with age. Happily, the fungus is not very virulent but is often the cause of decay in the tree-trunk--the brown-rot of the wood of this and other orchard and forest plants. In localities where the fungus thrives it may usually be controlled by covering all wounds with tar or other antiseptic materials.

At least two other fleshy fungi have been found injuring cherries. These are _Clitocybe parasitica_ Wilcox[65] and _Armillaria mellea_ Vahl.,[66] the latter the honey agaric, more or less abundant in both Europe and America. Both are associated with and are probably a cause of the root-rot of the cherry and other orchard fruits. Neither is a common enough pest in this country, however, to receive extensive description in texts on diseases of plants. Control measures are different in localities where fungi occur, consisting in the main of getting rid of stumps and roots in orchard lands and planting to field crops before using for orchard purposes. Infected trees should be removed or isolated by trenching about them.

All stone-fruits suffer more or less from an excessive flow of gum. The name gummosis[67] is generally applied to these troubles. Gumming is much more prevalent in the far West than in the East but is to be found wherever stone-fruits are grown. This excessive gumming is a secondary effect of injuries caused by fungi, bacteria, insects, frost, sunscald, and mechanical agencies. There is a good deal of difference in the susceptibilities of varieties and species to this trouble, the Sweet Cherry suffering much more than the Sour sorts and varieties of other species having hard wood suffering less than those having softer wood. There is less gummosis, too, on trees in soils favoring the maturity of wood; under conditions where sun and frost are not injurious; and, obviously, in orchards where by good care the primary causes of the diseases are kept out.

A number of diseases of the trunk arise from mechanical injuries from wind, sun, frost and hail. Few, indeed, are the fruit-growers whose trees are not occasionally damaged in one way or another in the vicissitudes of a trying climate. Very often these mechanical injuries are followed by fungal parasites or insects so as to make it difficult to distinguish the primary from the secondary trouble. There is a wide difference in the susceptibility of _Prunus avium_ and _Prunus cerasus_ to such injuries, the Sweet Cherry, with its softer wood, being much more easily injured by any and all stresses of weather than the Sour Cherry. In the main the elements cannot be combated but low heading of the trees is a preventive from sunscald, at least, and sometimes may have a favorable effect in preventing wind and frost injuries.

[55] Smith, E. F. Peach Rot and Peach Blight, _Journ. Myc._
=5=:123-134. 1889. Quaintance, A. L. The Brown Rot, etc., _Ga.
Sta. Bul._ =50=:237-269, figs. 1-9. 1900.

[56] Farlow, W. G. The Black Knot, _Bulletin Bussey Institution_
440-453. 1876. Halsted, B. D. Destroy the Black Knot, etc., _N. J.
Sta. Bul._ =78=:1-14. 1891.

[57] Duggar, B. M. _Fungous Diseases of Plants_ 185, fig. 68. 1909.

[58] Higgins, B. B. Contributions to the Life History and
Physiology of Cylindrosporium on Stone Fruits, _Am. Jour. Bot._
=1=:145-173. 1914.

[59] Aderhold, R. Mycosphaerella cerasella n. spec., die
Perithecienform von Cercospora cerasella Sacc. und ihre
Entwicklung, _Ber. d. deut. bot. Ges._ =18=:246-249. 1900.

[60] Duggar, B. M. _Fungous Diseases of Plants_ 314. 1909. Pierce,
N. B. A Disease of Almond Trees, _Jour. Myc._ =7=:66-67, Pls.
11-14. 1892.

[61] Duggar, B. M. _Fungous Diseases of Plants_ 226. 1909.

[62] Smith, E. F. and Townsend, C. O. A Plant Tumor of Bacterial
Origin, _Science_ =25=:671-673. 1907. Toumey, J. W. Cause and
Nature of Crown Gall, _Ariz. Sta. Bul._ =33=:1-64, figs. 1-31.
1900. Hedgcock, G. C. Crown Gall, etc., _U. S. Dept. Agr. Bur. Pl.
Ind. Bul._ =90=:15-17, Pls. 3-5. 1906.

[63] Scribner, F. L. Leaf Rust of the Cherry, etc., _U. S. Dept.
Agr. Rpt._ 353-355, Pl. 3. 1887.

[64] Atkinson, Geo. F. Studies of Some Shade Tree and Timber
Destroying Fungi, _Cor. Agl. Exp. Sta. Bul._ =193=:208-214. 1901.
Schrenk, H. von. Div. Veg. Phys. and Path., _U. S. Dept. Agl._
=25=:40-52, Pls. 11 (in part), 13. 1900.

[65] Wilcox, E. M. A Rhizomorphic Root-Rot of Fruit Trees, _Okla.
Agr. Exp. Sta. Bul._ =49=:1-32, Pls. 1-11. 1901.

[66] Duggar, B. M. _Fungous Diseases of Plants_ 473. 1909.

[67] Hedrick, U. P. Gumming of the Prune Tree, _Ore. Sta. Bul._
=45=:68-72. 1897.

CHERRY INSECTS

Insects troubling cherries are numerous but hardly as destructive as with other tree-fruits. Entomologists list about 40 species of insects attacking cherries and about as many more occasionally attack the varieties of one or the other of the two cultivated species. The majority of these pests came with the tree from its habitat over the sea but several have come from the wild cherries of this continent.

Of the pests peculiar to the cherry alone, possibly the cherry fruit maggot[68] (_Rhagoletis cingulata_ Loew) is, the country over, as troublesome as any. The adult insect is a small fly with barred wings which lays eggs under the skin of the cherry in mid-summer. From these eggs small, whitish maggots about one-third of an inch long hatch and eat out a cavity in the ripening fruit. These maggots when full grown pupate in the ground and remain there until the following season. The only effective preventive or remedial measure to take against the pest in large orchards is to spray with a sweetened arsenical, but in small plantations chickens are fairly effective in scratching up and eating the pupating maggots.

The cherry fruit maggot is probably responsible for most of the "wormy" cherries in New York but the plum curculio is also a cause of "wormy" fruits and in some seasons is a most formidable pest. This curculio[69] (_Conotrachelus nenuphar_ Herbst) is a rough, grayish snout-beetle somewhat less than a quarter of an inch in length, so familiar an insect as scarcely to need further description. The female beetle pierces the skin of the young cherries and places an egg in the puncture. About this cavity she gouges out a crescent-shaped trench, this cut or sting being a most discouraging sign to the cherry-grower, for he well knows that from the eggs come, within a week or two, white and footless grubs which burrow to the stone and make "wormy fruit." Some of the infested cherries drop but many remain eventually to distract the housewife and those who eat cherries out of hand. Jarring the beetles from the trees, a method employed by plum-growers, is quite too expensive and ineffective for the cherry-grower and poisoning with an arsenate is the only practical means of combating the pest. Rubbish and vegetation offer hiding places for the insects and, therefore, cultivated orchards are freer from curculio than those laid down to grass. There are no curculio-proof cherries but, as with plums, the thin-skinned varieties are damaged most by the insect.

The grub of the plum curculio is easily distinguished from the cherry fruit maggot. This "worm" is the larva of a beetle, a true grub, footless and with a brownish, horny head while the cherry fruit maggot, the larva of a two-winged insect, is a true maggot like that which comes from the common house-fly and hardly to be distinguished from the apple maggot. It is important to be able to distinguish in wormy cherries the grub of the curculio from the cherry fruit maggot in order to know and understand the nature of the two enemies in combating them.

Another pest of this fruit is the cherry leaf-beetle (_Galerucella cavicollis_ Le Conte) the larvae of which sometimes do much damage to cherry foliage. The adult insect is an oval, reddish beetle about one-fourth of an inch long with black legs and antennae. Both the adult and the larvae feed on the leaves and do much damage if abundant. Usually there are two broods, the insect pupating in the ground. Fortunately the pest is easily controlled with the arsenical sprays.

The cherry scale (_Aspidiotus forbesi_ Johnson) is commonly found on this fruit and occasionally on others as well. To the unaided eye it is very similar to the well-known San José scale, differing chiefly in being lighter in color. The remedy is the same as for the San José scale, which we next discuss.

The dreaded San José scale[70] (_Aspidiotus perniciosus_ Comstock) is rather less harmful to cherries than to other tree-fruits and yet is sometimes a serious pest on Sweet Cherries. Sour Cherries are almost immune. The insect is now so well known in all fruit-growing regions that it needs no description. It is usually first recognized by its work, evidence of its presence being dead or dying twigs--oftentimes the whole tree is moribund. Examination shows the twigs or trees to be covered with myriads of minute scales, the size of a small pin-head, which give the infested bark a scurfy, ashy look. If the bark be cut or scraped a reddish discoloration is found. Leaves and fruit as well as bark are infested, the insidious pest, however, usually first gaining a foothold on the trunks or a large branch. Cherry-growers, in common with all fruit-growers, find the lime and sulphur solution the most effective spray in combating this insect.

Several other scale insects feed on the cherries and, now and then, become pestiferous; among these the following may be named: The European fruit lecanium[71] (_Lecanium corni_ Bouché) occasionally does a great deal of damage in New York and now and then destroys the whole crop in an orchard. The winter treatment for San José scale is used to control this pest, but usually such treatment is supplemented by a summer spray about July first with such contact sprays as whale oil soap and kerosene emulsion. The fruit pulvinaria (_Pulvinaria amygdali_ Cockerell), the mealy bug (_Pseudococcus longispinus_ Targioni), the scurfy scale (_Chionaspis furfura_ Fitch), the West Indian peach scale (_Aulacaspis pentagona_ Targioni), the Putnam scale (_Aspidiotus ancylus_ Putnam), the walnut scale (_Aspidiotus juglans-regiæ_ Comstock), Howard's scale (_Aspidiotus howardii_ Cockerell), the European fruit scale (_Aspidiotus ostreæformis_ Curtis), the red scale of California (_Chrysomphalus aurantii_ Maskell), the oyster-shell scale (_Lepidosaphes ulmi_ Linnaeus), and the soft scale (_Coccus hesperidum_ Linnaeus), are all more or less common.

Several borers occasionally infest cherry trees of which the peach borer[72] (_Sanninoidea exitiosa_ Say.) is the most troublesome. Larvae of the peach borer are frequently found in both Sweet and Sour Cherries, more particularly in Sweet Cherries, in eastern orchards. Fortunately this pest is not as rife with the cherry as with peaches and plums. Its work may be prevented by thorough cultivation, by mounding the trees and, according to some, by the use of a covering of tar or of obnoxious or poisonous washes. Usually preventive measures are not effective, however, and the borer must be destroyed--best done by digging it out with a knife and wire. Since the pest is easily discovered through the exudation of gum mixed with sawdust or excreta, close to the surface or just beneath the ground, its presence can be detected in time to prevent its doing much damage. The lesser peach borer[73] (_Sesia pictipes_ Grote & Robinson) often attacks old or weakened cherry trees, working in the growing tissues of the trunk anywhere from the ground to the main branches. The worm is much like the common peach borer, known by all, but is smaller, rarely reaching the length of four-fifths of an inch when full grown. The flat-headed apple tree borer[74] (_Chrysobothris femorata_ Fabricius) is a common pest in wild cherries and sometimes seriously attacks the cultivated species. It is treated as is the peach borer.

The shot-hole borer[75] (_Eccoptogaster rugulosus_ Ratzeburg), though seldom injuring healthy trees, is very often a serious menace in old or decrepit cherry trees. It may be looked upon, however, as an effect rather than a cause. The peach bark-beetle[76] (_Phlæotribus liminaris_ Harris) is very similar in its work to the shot-hole borer and like it attacks only diseased and decrepit trees.

All cherry-growers are familiar with the small, dark green, slimy slugs which feed on the surface of the leaves of the cherry, possibly more common on the foliage of pears, eating out the soft tissues and leaving but the skeleton of the leaf. If the slugs are numerous the tree may be defoliated or if the leaves remain the foliage looks as if scorched. The adult of this slug is a sawfly (_Caliroa_ (_Eriocampoides_) _cerasi_ Linnaeus) which lays its eggs within the tissue of the leaves. Despite the fact that it is easily destroyed by any of the arsenical sprays or by dusting with lime this slug everywhere does much damage to cherries.

Wild cherries suffer severely from the tent caterpillar[77] (_Malacosoma americana_ Fabricius) and occasionally cultivated trees are attacked. The arsenical sprays are fatal to the pest. The spring canker-worm[78] (_Paleacrita vernata_ Peck) and the fall canker-worm[79] (_Alsophila pometaria_ Harris), the white-marked tussock moth (_Hemerocampa leucostigma_ Smith and Abbot), the rusty tussock moth (_Hemerocampa antiqua_ Linnaeus), and the definite-marked tussock moth (_Hemerocampa definita_ Packard) are all occasional cherry pests and all succumb to poisonous sprays. The two now notorious European pests recently introduced into America, gypsy moth (_Porthetria dispar_ Linnaeus) and the browntail moth (_Euproctis chrysorrhæa_ Linnaeus), attack cherry trees in common with other deciduous trees and may often do considerable damage. Sometimes, but not often, the buds of the cherry are attacked by the bud-moth (_Spilonota_ (_Tmetocera_) _ocellana_ Schiffermüller), the caterpillars of which bind the young leaves together as they expand so that small, dead, brown clusters of foliage are to be seen here and there where the pests are at work. Spraying with arsenicals is effective if done just as the buds begin to open.

In sandy soils the cherry is sometimes attacked by hordes of the common rose-chafer (_Macrodactylus subspinosus_ Fabricius), leaves, flowers and even the fruit suffering from the pest. It is a difficult insect to control but a spray of arsenate of lead with molasses is fairly effective. It is important to know that the insect does not often breed in ground kept in clean cultivation.

[68] Slingerland, M. V. _Bul. Cor. Ag. Ex. Sta._ =172=: 1899.

[69] Riley, C. V. _An. Rpt. State Entom. Mo._ =1=:50-56. 1869;
=3=:11-29. 1871.

[70] Marlatt, C. L. The San José or Chinese Scale, _U. S. D. A.
Bur. Ent. Bul._ =62=:1-89. 1906.

[71] Lowe, V. H. The New York Plum Lecanium, _N. Y. Sta. Bul._
=136=:583. 1897.

[72] Beutenmüller, _W. Sesiidae of America_, etc. 266-271. 1901.

[73] _Ibid._ 291-292. 1901.

[74] Riley, C. V. _An. Rpt. State Entoml. Mo._ =1=:46-47. 1869.

[75] Lowe, V. H. _N. Y. Sta. Bul._ =180=:112-128. 1900.

[76] Wilson, W. F. The Peach-tree Bark-beetle, _U. S. D. A. Bur.
Ent. Bul._ =68=:91-108. 1909.

[77] Lowe, V. H. The Apple-tree Tent Caterpillar, _N. Y. Sta.
Bul._ =152=:279-293. 1898.

[78] Riley, C. V. _An. Rpt. State Entom. Mo._ =2=:94-103. 1870.

[79] _Ibid._ =7=:83-90. 1875.