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By M. P. ZAPPE AND G. P. CLINTON:
mation 33, April 15. By R. C. BOTSFORD: Accomplishments in the Past Year in Anti-Mosquito Work in Connec
ticut, Proceedings 11th Annual Meeting of the New Jersey Mosquito Extermination Association, page 80, 1924.
DEPARTMENT STAFF AND WORK.
The only change in the staff during the year was the appointment of Mr. Roger B. Friend, who began his duties January 1, 1924, as part time assistant. Mr. Friend graduated from the Massachusetts Agricultural College in 1923, and was employed for the remainder of that year by the Conservation Commission of New York State, on gipsy moth work. Mr. Friend is studying at Yale University for his doctorate, and is employed at the Station during the time when not busy with his studies. He is investigating the bionomics of the birch leaf skeletonizer and has also given considerable attention to control methods of certain insects attacking vegetable crops. Articles occur elsewhere in this Report giving the results of Mr. Friend's work on Substances Attractive to the Cabbage Maggot Fly, and Experiences in Dusting to Kill the Pea Aphid, Cabbage Aphid and Onion Thrips.
Mr. J. Leslie Rogers was employed as assistant from February 25 until the end of the year. He was engaged until the nurseries had been inspected, then was continued to help in scouting for the European corn borer. Mr. T. F. Cronin was also employed to assist in inspecting nurseries, working from June 23 until September 15, when he returned to his studies at the Connecticut Agricultural College at Storrs. Mr. W. R. Hunt, graduate assistant in the Botanical Department of this Station, was placed on the pay roll of this Department for the three months from July 1 until October 1, and assisted in the inspection of nurseries, paying particular attention to plant diseases.
Mr. Walden has done most of the photographic work of the Department, has had charge of the office in the absence of the Entomologist, and has assisted in scoring apples in the dusting and spraying experiments. He has also conducted some research work on the imported currant worm, Pteronidea ribesi Scop.
Mr. Zappe has been in charge of the inspection of nursery stock, and of scouting and clean-up work on account of the European corn borer in co-operation with the Federal Bureau of Entomology. He and Dr. Garman have investigated the life history and control of the Asiatic beetle, and the plum curculio as a pest of apple orchards. In co-operation with Mr. Stoddard of the Botanical Department, he has made further tests of various dusts in comparison with sprays for the control of various insect and fungous pests of apple orchards.
Dr. Garman has conducted investigations regarding methods of control for the Oriental peach moth, the American foul brood disease of bees, has continued his studies on life histories and habits of spittle insects, the European red mite, and, as noted above, jointly with Mr. Zappe, has investigated the plum curculio, and the Asiatic beetle. Dr. Garman has also constantly revised his manuscript on the Odonata or dragon flies of Connecticut, which is now ready and will sometime be published as a bulletin of the State Geological and Natural History Survey.
Mr. Botsford has continued to serve as Deputy to Director W.L. Slate in charge of mosquito elimination work, and Miss Finley has done the necessary clerical and stenographic work of the Department.
The gipsy moth control work has been prosecuted vigorously as in past years, the field work being entirely in charge of Deputy John T. Ashworth, assisted by James A. McEvoy. This work is carried on in co-operation with the Federal Bureau of Entomology and is fully described in this Report.
The apiaries have been inspected as in past years by Messrs. H. W. Coley and A. W. Yates, on a per diem basis.
The Entomologist, besides directing the work of the Department and attending to the correspondence of the office, has continued to serve as Associate Editor of the Journal of Economic Entomology, as Chairman of the Tree Protection Examining Board, and as Insect Pest Reporter for the Insect Pest Survey of the Federal Bureau of Entomology. He has in preparation a list of additions and corrections to the Check List of the Insects of Connecticut, which it is hoped can be published at an early date by the State Geological and Natural History Survey.
Messrs. Britton and Walden are collaborators of the Federal Horticultural Board, and Zappe, Garman, Friend and Ashworth are collaborators of the Bureau of Entomology.
In July, a new Chevrolet touring car was purchased and was used nearly all of the time for transporting the men while engaged in the work of inspecting nurseries.
The more important activities of the Department are described in the various papers in the following pages of this Report.
ENTOMOLOGICAL FEATURES OF 1924. The season of 1924, like that of 1923, was abnormal and began with cool moist weather followed by a drought. Very little rain fell between July 1 and October 1, and the drought of 1924 was even more severe than that of 1923.
Some of the outstanding features of the season were the disappearance in injurious numbers of the apple and thorn skeletonizer, which was so abundant in 1923, the greater increase in the Oriental peach moth, and further infestations of the European corn borer in six towns along the coast.
There has been no serious spread of the gipsy moth, though a few additional towns were found infested by the Federal scouts. Because it was not possible for the Federal men to scout the entire southern portions of New Haven and Middlesex Counties and it was not known whether or not they were infested, some 23 additional towns were included in the quarantined area.
Though a watch has been kept, not a single nest of the browntail moth has been seen in Connecticut since 1919.
FRUIT INSECTS. The tent caterpillar, Malacosoma americana Fabr., continued to be abundant throughout the State, though particularly so in the western portion. Every 10 or 12 years this insect reaches its period of greatest abundance, being comparatively scarce half way between these high periods, probably checked by natural enemies.
The fall canker worm, Alsophila pometaria Harris, which is present locally somewhere in the State nearly every year was very abundant in Greenwich and Stamford in early summer and stripped many kinds of deciduous trees, apple, elm, hickory and oak being particularly injured. A few caterpillars were found feeding on maple, but the trees were not stripped. Around New Haven, this insect was present in destructive numbers, but no injury was observed or reports of injury received from outside of New Haven and Fairfield Counties. See Plate XXXII.
The apple and thorn skeletonizer, Hemerophila pariana Clerck, which was so prominent and was responsible for so many brown apple trees in 1923, was conspicuous by its absence in 1924. Evidences of its presence could be found in nearly every orchard by the slight skeletonization on terminal leaves, but its work had been arrested, the caterpillars were not there and no particular damage had been done. Apparently natural enemies have been unusually prompt in subduing this insect.
On the other hand, the Oriental peach moth, Laspeyresia molesta Busck, was much more in evidence than in 1923, and wormy peaches were rather common in Fairfield and New Haven Counties, late in the season. If this pest continues to spread, its control will
become one of our most important problems. Further details will be found elsewhere in this Report.
The European red mite, Paratetranychus pilosus Can. and Fanz., was less abundant in 1924 than in 1923, and no serious injury from its attacks was brought to my attention. Eggs were present in winter in many orchards, especially in the northern portion of the State, but spraying the dormant trees with miscible oils was generally practiced with satisfactory results. Probably the wet spring may have reduced the numbers of this pest, for it was not evident later in the season in most orchards, and I have yet to learn of a single case where it was considered necessary to give a summer spray in 1924 for its control.
The sinuate pear borer, Agrilus sinuatus Oliv., continues to spread eastward and it causes some injury at first. This European insect first appeared in the United States in New Jersey some 20 years ago, caused serious injury there for a few years, but is now not regarded as a serious pest. It was first recognized in Connecticut in 1917 at Norwalk, and the writer observed its destructive work in a pear orchard in Stamford in 1920. In May 1924, after the receipt of specimens, Mr. Zappe visited the premises of Mr. W. T. Camp, Shelton, where several old trees had been nearly killed by this insect, and had been removed. Other pear trees in the vicinity had been more or less injured. Probably the best treatment consists in removing and burning the seriously injured trees and branches; then cut out the borers from the remaining portion and coat the bark with a wash of lime-sulphur and lead arsenate to repel the beetles and possibly kill the larvae when they enter the bark. The foliage should also be kept covered with lead arsenate during May and June to kill the adult beetles which feed there before laying eggs. If the trees are kept well fertilized and cultivated, they will be more apt to outgrow injury caused by this insect.
Males of the lime tree winter moth, Erannis tiliaria Harris, were fairly abundant flying about lights in the fall, and the greenishyellow black-spotted females were found on tree trunks. The caterpillars feed upon apple trees and on elm, linden and other trees in the woodlands. The caterpillars feed at about the same time as canker worms, but are larger and there is danger that they will cause some damage the coming season. Spraying with lead arsenate is the remedy. Further information will be found on page 311 of this Report.
The light or false apple red bug, Lygidea mendax Reut., was rather less abundant than usual, though it caused some injury locally here and there. Fruit injured by it in Wallingford and Danbury was brought to our attention.
The rosy apple aphis, Anuraphis roseus Baker, was rather scarce in most orchards early in the season, though egg-infested twigs were received in March from Middlebury, Middlefield, Milford, Cannondale and South Glastonbury. On June 9 it was observed in Stamford and Wallingford. By June 24, it was present in moderate numbers in nearly every orchard and injury was caused by it in some cases.
The green apple aphid, Aphis pomi DeGeer, hatched in April, and on the 25th at Milford there was an average of about one aphid per bud, but on May 22, practically all aphids had disappeared in the orchards under observation in Milford, New Haven, Hamden and Cheshire.
The woolly apple aphid, Eriosoma lanigerum Hausm., seems to be present in nearly every orchard though it is uncertain just how much injury is caused by it. Further information regarding this insect may be found on page 308 of this Report.
The pear psylla, Psylla pyricola Foerster, was abundant on pear trees in Wallingford, Southington, Hebron and other places, though in one garden it was less common then for several years. It can be controlled by dormant sprays of nicotine solution and soap, of lime-sulphur and of miscible oils. Sometimes it may be necessary to give a summer treatment either as a spray or dust to prevent blackening of the fruit by later broods.
Leafhoppers were abundant on apple foliage, May 22, in Milford, Hamden and Cheshire.
The plum curculio, Conotrachelus nenuphar Herbst, yet remains one of the important pests of the apple orchard and series of experiments have given results which though somewhat contradictory, seem to indicate that thorough applications of lead arsenate at the pink, calyx and two weeks spray, will give fair control. Scarcely any additional benefit could be seen from the seven day treatment. Dr. Garman and Mr. Zappe have already worked two seasons on the five-year program for the study and control of this insect in apple orchards.
The currant aphid, Myzus ribis Linn., was present as usual on currant bushes, and specimens were received from Hebron on May 9, and from Colchester on May 16.
A particularly striking case of injured currant twigs attacked by the currant stem girdler, Janus integer Nort., was brought to the Station from Woodbridge in April.
VEGETABLE INSECTS. Most of the common insect pests of the vegetable garden were present in 1924, but on account of the backwardness of the season, appeared two or three weeks later than usual. The absence of rain during July, August and September was favorable to some
ds of insect life and unfavorable to plant growth.
The usual amount of injury was caused by cutworms. During June, reports were received of injury to nearly all kinds of vegetable plants in New Haven County, but probably such injuries were not confined to one county but occurred all over the State. A more