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The eggs of Clastoptera proteus are similar to that of the alder bug C. obtusa and are laid beneath the bark on the outer twigs. They are sometimes thrust directly into the plant parallel to the axis of the stem and sometimes diagonally. Not more than three have been observed in a single puncture though only one may sometimes be found in each. Some of the characteristic punctures are shown on Plate XXX, f.

Total length .7 mm. greatest width .35 mm.; rounded at one end and tapering to a rather definite point at the other.

The eggs of six species representing four of the five genera of spittle-bugs occurring in this section are now known; leaving only the egg laying habits of Aphrophora species yet to be discovered. In general it may be stated that those eggs known so far are similar in form, being pointed at one end and rounded at the other, the only great differences being those of size. All are placed on the plants themselves, being either thrust into dead stems, into the sheath of the growing plant or just beneath the bark on new growth. The function of the rather stout ovipositors of members of the group therefore is plainly evident.

A list of references relating to the eggs and egg laying habits is given herewith.

Philaenus lineatus (Linnaeus), Barber, G. W. and Ellis W.O., Psyche, 29:3: 1922. Garman P., Conn. Agr. Exp. Station, Bull. 230; p. 328: 1921.

Philaenus leucophthalmus (Linnaeus), Barber, G. W. and Ellis W.O., Psyche, 29: 3: 1922.

Clasto ptera obtusa (Say) Garman, P., Ann. Ent. Soc. Amer., 16: 155: 1923.

Lepyronia quadrangularis (Say) Garman, P., Ann. Ent. Soc. Amer., 16: 160: 1925. Doering, Kathleen. Kans. Úniv. Science Bull., 14: 536:

Philaronia bilineata (Say). Barber, G. W. and Ellis W. O., Psyche, 29: 3: 1922.

1922.

THE WOOLLY APHID OF APPLE AND ELM.

Eriosoma lanigerum Hausman. The apple tree woolly aphid is said to occur throughout the world wherever the apple is grown. In England it is called the "American blight” and in Germany the "Blutlaus.” It is a bark feeding aphid with two forms; one on the roots and the other on the twigs and branches. It is generally noticeable above ground, on account of the bluish-white patches on the twigs, shown on Plate XXIX, c with reddish-brown aphids close to the bark. The whitish color is due to many minute filaments of wax secreted and protruded by small pores in the epidermal coverings of the bodies of the aphids. These aphids often cluster in wounds such as scars, cankers or where branches have been cut off, and prevent their healing. In some cases, galls are formed on the twigs by the clusters of woolly aphids, and these galls together with the

whitish wax adhering around the margins of wounds are an indication of the presence of the pest. Several years ago, a seedling apple came up in a protected place just south of one of the Station buildings, where it was allowed to grow for several years. Each summer nearly every branch bore one or more of the bluish white patches, each patch being a colony of woolly aphids. Later the little tree was literally covered with swellings or galls on the twigs and branches as the result of the infestation, and the tree was finally removed to make room for needed improvements.

On the roots, galls are nearly always formed by this insect, and where this infestation is heavy, the root system may be only a mass of galls. These galls decay, often ruining the root system of the tree. I well remember some 12 years ago, a man in Groton purchased several hundred apple trees from a Tennessee nursery, and when they arrived, many of the trees had lost all of the smaller roots by decay following woolly aphid infestation. Some of the old stump roots were photographed and are shown on Plate XXIX, b. Most of the trees had galls on the roots but many of them had decayed and were worthless for planting. I was asked to make a statement and issue a certificate regarding the condition of this stock, to be used by the purchaser in making adjustment with the nurseryman. I also wrote to the nurseryman and to the official in charge of nursery inspection in Tennessee, and hope that such stock will not again be shipped into Connecticut. The root form also produces the white wax filaments but these are shorter and less conspicuous than is the case with the aerial form.

The woolly aphid is a much more serious pest further south than in Connecticut, but no doubt it causes some damage here. Nursery trees and young orchard trees are more seriously injured than larger and older orchard trees. The Northern Spy and some other varieties are said to be more or less exempt from attack. In examining apple twigs in the spring of 1924, evidences of the presence of woolly aphid were found in every one of 18 orchards submitting twigs, covering all parts of the State except New London and Windham Counties. Though perhaps the woolly aphid is not a major pest in Connecticut, some attention should be paid to it particularly in nurseries, and in newly established orchards. We believe that it will not seriously injure trees in Connecticut after they have become well established and have reached bearing size.

Gillette and Taylor state that "If Colorado orchardists should vote their opinion as to what ought to be called the worst orchard pest in the State, it is very doubtful whether the codling moth or the woolly aphis would carry off the honors."

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LIFE HISTORY. The winter eggs are laid in the crevices of the bark on elm trees probably in September, and hatch in early spring. The aphids hatching from these eggs are wingless females, called stem mothers, which feed upon the expanding leaves and become mature laté in May and cause the leaves to curl or form rosettes. Their young are also wingless and are born alive like the other summer generations of most aphids. The next generation, however, have wings and are known as spring migrants; they mature the latter part of June and migrate to apple trees. Sometimes they go to pear, quince, hawthorn or mountain ash. There are three summer generations in Maine and in August winged females appear and shortly afterward lay the winter eggs.

According to Slingerland and Crosby, the development of the root form is quite similar to that of the form on the twigs and branches, though perhaps not fully worked out; also that "many of these wingless agamic nymphs persist on the roots, and some of them even on the tree above ground, all the year through even in New York State and other cold northern latitudes."

CONTROL MEASURES. In general, orchardists should be advised not to plant trees with many galls on the roots. Nursery trees which have been seriously injured by the woolly aphid should be destroyed. Those which are not injured but which show evidences of infestation should before planting be either fumigated with hydrocyanic acid gas, or treated by dipping the roots in a nicotine solution containing a spreader, or in kerosene emulsion containing 15 per cent. kerosene. Hot water (1300-150° F.) is also recommended. Lime sulphur, however, should not be used, as it may cause injury to the small roots.

In Missouri in 1896, experiments were rather successful in treating ten year old trees in the orchard by removing four inches of the top soil around each tree for a distance of two feet from the trunk and scattering evenly over this area four or six pounds of tobacco dust, then replacing the soil. With nursery trees, the dust was placed in trenches close beside the rows. In Georgia: more than ten years later, similar and more detailed experiments with various forms of tobacco in excavated areas and trenches gave very unsatisfactory results, but by removing three inches of the surface soil extending from one and one-half to four feet from the trunks, depending upon the size, and treating with 15 per cent. kerosene emulsion, good results were obtained. From three gallons of this emulsion on the smaller areas, to six gallons on the larger, saturated the soil to a depth of from two to four inches, and it gradually permeated the soil to a depth of a foot or more and the odor lasted for many weeks.

During the seasons of 1914 and 1915, Mr. B. R. Leach of the Bureau of Entomology, conducted experiments against the woolly aphis in Virginia using various materials including kerosene emulsion, sodium cyanide, and carbon disulphide emulsion. His best results were obtained with carbon disulphide emulsion at the rate of one-half pound in four gallons of water, thoroughly agitated. A shallow basin was made around the tree and three-fourths of a gallon of the emulsion per square foot of soil was applied in the basin. He found this method quite satisfactory on small trees, where the conditions are favorable. The applications can be made at any time during the summer months, but are successful only when the soil is moist. Since Mr. Leach carried on these experiments, a soap emulsion of carbon disulphide has been manufactured and is now sold on the market. It is also possible to make at home a fairly good emulsion, and it is believed that these soap emulsions would also be effective in killing the root forms of woolly aphis, particularly after the proper proportions have been determined. Such emulsions have been used in this Department to kill the grubs of the Asiatic beetle, and did not injure the grass.

The aerial form of the woolly aphid can readily be killed by spraying with kerosene emulsion, or with nicotine sulphate and soap.

LITERATURE. The economic literature of this species is very voluminous, and only a few references are given here. 1 Gillette, C. P., and Taylor, E. P., Bulletin 133, Colorado Agricultural

Experiment Station, page 5, 1908. * Leach, B. R., Bulletin 730, United States Department of Agriculture,

pages 29-40, 1918. • Patch, Edith M., Bulletin 256, Maine Agricultural Experiment Station,

1916. · Slingerland, M. V., and Crosby, C. R., Manual of Fruit Insects, page 156, 4

1914. • Smith, R. I., Bulletin 23, Georgia State Board of Entomology, 1907. • Stedman, J. M., Bulletin 35, Missouri Agricultural Experiment Station, 1896. THE LIME TREE WINTER MOTH.

Erannis tiliaria Harris. This native American insect occurs throughout the eastern United States and Canada, westward to the Rocky Mountains. The larvae feed upon the foliage of apple, pear, linden, birch, elm, oak and hickory and probably other forest trees. As a rule it is not very abundant in Connecticut and therefore little attention has been paid to it. Occasionally it becomes so abundant as to cause damage by defoliating trees, and such may be the case in Connecticut in 1925, as the male moths were very abundant in October and November, flying around electric lights in cities and villages. Not only were the moths noticeable in Connecticut, but were reported as being abundant throughout Massa

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chusetts and portions of New York State. On November 1, a specimen of the male was received from Sharon with a statement that it was very abundant there, and since then I have learned that the caterpillars of this insect in the summer of 1924 caused noticeable damage to the beautiful elm trees on the village green. Hence, all persons responsible for the care of valued shade trees, whether on public or private grounds, should be warned to look out for the depredations of this insect early in the coming summer.

Other common names of the caterpillars are: lime tree span worm, lime inch worm and ten-lined inch worm,

INJURY.

The injury consists in the caterpillars feeding upon the leaves during the month of May. This may well be ascribed to canker worms as it has a similar appearance and occurs at about the same time. In fact the larvae or caterpillars are often found feeding with canker worms, but as they are larger and have a more distinctly yellowish color on the lower portion of the sides and on the under surface, they can readily be distinguished from them. In 1912, this insect appeared in large numbers in western New York, and riddled the foliage of apple and cherry trees along the roadsides and to some extent in commercial orchards. Linden and elm trees were also partially defoliated. In 1914, an outbreak of this insect was reported from Ulster County, N. Y., and orchard and woodland trees were attacked.?

At first the caterpillars eat elongated holes, but when they are abundant they completely riddle the leaves.

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HABITS AND LIFE HISTORY. Like the canker worms, this insect has one generation annually, the females are wingless, the caterpillars feed upon the leaves at the same time of the year and loop in crawling. The eggs hatch in April or early in May and the caterpillars become fully-grown early in June and transform to the pupa stage in cells in the ground. Some may pupate in May and usually all have pupated by the middle of June. The caterpillars have the habit of remaining rigid in one position or feigning death, sometimes fastened only at one end and the other standing out in a straight line like a twig. In Connecticut the adults for the most part emerge in the fall, though according to Dr. Saunders, in Canada fall emergence is rare and most of them emerge in spring.

One of the best biological accounts of this insect published in recent years is by Professor W. J. Schoene, in Bulletin 421, of the New York (Geneva) Agricultural Experiment Station, page 376, Plates V and VI, May, 1916, and the present writer has drawn upon it freely. Professor Schoene records no observations on the hatching of the eggs, but states that the females in a cool

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