Digitized by the Internet Archive in 2011 with funding from LYRASIS members and Sloan Foundation http://www.archive.org/details/reportofstateent445conn S 3 n^> Bulletin 445 July, 1941 E^ Connecticut State Entomologist fortieth report 1940 R. B. FRIEND, Ph.D. State Entomologist (Ktmuecttcui Agricultural ^fccpertmati jitfatirm To the Director and Board of Control Connecticut Agricultural Experiment Station: I have the honor to transmit, herewith, the fortieth report of the State Entomologist. This gives an account of the activities of the Department of Entomology, both regulatory, as prescribed by Sta- tute, and research, for the year ending October 31. 1940. In addi- tion to the accounts of progress in research given in this report, members of the Department have published several papers in journals, bulletins, circulars, etc., a list of which is appended. Respectfully submitted, R. B. Friend, State and Station Entomologist. CONTENTS Page Insect Record for 1940 295 Conference of Connecticut Entomologists 297 Inspection of Nurseries, 1940 299 Number and Size of Nurseries 300 Connecticut Nursery Firms Certified in 1940 300 Other Kinds of Certificates Issued 307 Inspection of Imported Nursery Stock 307 Japanese Beetle Quarantine Activities, 1940 308 Scouting 309 Inspection and Certification 309 Inspection of Apiaries, 1940 310 Statistics of Inspection 312 Financial Statement 313 Registration of Bees 313 Report on the Gypsy Moth, 1939-1940 313 Introduction 313 New Equipment 315 Control Operations 315 Work performed by state men 315 Work performed by C.C.C. men 317 Work performed by W.P.A 317 Scouting for Brown-Tail Moth 317 Dutch Elm Disease 322 Mosquito Control in Connecticut, 1940 322 Rodent Control 324 Pine Mice 324 Meadow Mice 326 Rabbit Repellent Study 327 Report on Parasite Work for 1940 328 Oriental Fruit Moth Parasites 328 Japanese Beetle Parasites and Disease 330 Nematode Parasites 331 Continued Study of Stickers for Spray Matelials 331 Experimental Control of the Oriental Fruit Moth 336 Experimental Control of the Apple Maggot 339 Laboratory Work 339 Field Studies 340 Notes on the Codling Moth in Connecticut 347 Observations on the European Corn Borer (Pyrausta nubilalis Hubn.) 348 ^ 1 CONTENTS— Continued Page European Corn Borer Insecticide Investigations 357 First Generation Tests 357 Second Generation Tests 359 Control of the Cabbage Maggot 361 Seasonal Development of the Japanese Beetle and Spraying for the Adult Insect $63 The Black Vine Weevil and Its Control 367 Notes on the Control of Mound-Building Ants 870 Control of the Hairy Chinch Bug, Blissus hirtus Montandon &72 Chemical Repellents to Bark Beetle Breeding 374 Notes on the European Earwig for 1940 875 Miscellaneous Notes 376 An Infestation of a European Sawfly, Gilpinia frutetorum L 376 Calomycterus setarius Roelofs 376 Clover Mites, Bryobia praetiosa Koch 377 Notes on the House Cricket, Gryllus domesticus L 377 A Hemlock Looper, Ellopia athasaria Walker 377 Mastophora cornigera (Hentz), a Spider New to New England .... 379 Publications, 1940 381 Index 383 Dusting corn during the evening for control of the borer. CONNECTICUT STATE ENTOMOLOGIST FORTIETH REPORT 1940 R. B. Friend INSECT RECORD FOR 1940 HP HE Japanese beetle (Popillia japonica Newm.) is increasing in A abundance in the State and will probably so continue for the next few years. It is already a serious pest in certain towns and has been very injurious to ornamental trees and shrubs, vineyards, and at least one orchard. The insect is most abundant in and around Hartford and in Branford, New Haven, Hamden, Bridgeport, and Greenwich. The gypsy moth (Porthetria, dispar L.) caused no noticeable defoliation of trees during 1940, although present in much of the State. The severe outbreaks in the Granby-Simsbury area and on the Southbury-Roxbury line, where extensive control operations were carried out in 1939, have subsided to an innocuous level. The elm leaf beetle {Galerucella luteola Muller) was unusually abundant and injurious to elms. Large numbers of trees were com- pletely defoliated. A geometrid caterpillar (Ellopia athasaria Walker) defoliated hemlock stands in Woodbridge and Branford. A grasshopper {Melanoplus punctulatus Uhler) defoliated num- bers of small white pines in plantations in Rainbow and Branford. The Dutch elm disease has continued to spread, and infected trees were discovered in 17 new towns in Litchfield, Fairfield, and New Haven counties, and in one town, Preston, in New London County. Scolytus multistriatus Mars., the principal vector, has never been found in Preston. The apple maggot (Rhagoletis pomonella Walsh) was very abundant and injurious. A disconcertingly severe outbreak of the codling moth (Carpo- capsa pomonella L.) occurred in an orchard in Middlefield. Injury to the peach crop by the Oriental fruit moth (Grapholitha molesta Busck) was somewhat greater than in 1939. 296 Connecticut Experiment Station Bulletin 445 The red-banded leaf roller (Argyrotaenia velutinana Walk.) was less abundant than in 1939. Pears in an orchard in Fairfield County were infested with mealybugs {Pseudococcus comstocki Kuw.). This pest has not previously been found on fruit in the State, although it has injured apples in Virginia in recent years. The European corn borer (Pyrausta nubilalis Hubn.), although not generally so abundant as in 1939, severely injured the corn crop. Investigators of the Federal Bureau of Entomology and Plant Quar- antine estimated the loss in Connecticut in 1940 due to this borer at approximately $43,000 and $416,000 to grain corn and sweet corn, respectively. | The European earwig (Forficula auricularia L.) was fairly common in a restricted locality in New Haven. The pine mouse (Pitymys pinetorum) and meadow mouse {Microtus pennsylvanicus) populations in the State were generally rather low during the year. During 1940, 576 samples of insects were received at this office about which information was desired. These are classified under th^ following economic groups: Specimens Received — 1940 Fruit pests 31 Field, vegetable, and truck crop pests 11 5 Forest and shade tree pests 173 Pests of shrubs and vines 32 Flower and greenhouse pests 29 Household and stored food products pests 97 Timber and wood products pests 74 Soil and grassland inhabiting pests 48 Insects annoying man and domesticated animals 15 Parasitic and predaceous insects 20 Miscellaneous 46 576 This list does not show the relative abundance or economic im- portance of the different groups in the year's survey of the insect pests of the State. Many of these insects are sent in by residents of the urban sections of the State who do not have direct contact with members of the department, while many of the farmers, fruit grow- ers, and market gardeners may obtain their information direct from department members when examining their crops or attending local gatherings of these various groups. Termites or their work, as in the past six years, head the list, having been sent in 29 times from 21 different localities. The elm leaf beetle was received 24 times from 19 different localities. Many of the specimens were hibernating adults from houses, indicating Insect Record for 19 UO 297 early in the spring that the pest was widespread and would probably cause more than the average amount of injury to elms. The black carpet beetle, an important household pest of woolens, was next on the list, with 22 records. Carpenter ants were sent in 15 times. The spruce mite, which often injures the foliage of a variety of ornamental evergreens, was received 1 1 times. Japanese beetle adults and grubs were represented by 9 lots. There were 8 samples of euonymus scale, an injurious pest especially of the evergreen vine, Euonymus radicans, on which it is difficult to control. The following insects were each received five or six times: Calomycterus setarius Roelofs, an introduced weevil which is espe- cially troublesome due to its habit of crawling into houses. This insect, previously reported from Fairfield and Litchfield counties, was received in 1940 from Farmington and West Hartford in Hart- ford County. The pine leaf scale, Chionaspis pinifoliae Fitch, a conspicuous pest on the needles of various ornamental pines. Tulip tree scale, Toumeyella liriodendri Gmel., one of our largest scale insects, which attacks the tulip tree. Phymatodes variabilis Fabr., a long-horned beetle often found emerg- ing from firewood in basements. Bladder maple gall, Phyllocoptes quadripes Shim., a conspicuous mite gall on soft maples. Gouty maple gall, Dasyneura communis Felt, a midge gall on sugar maple. Tetralopha robustella Zell., a moth, the larvae of which produce con- spicuous frass masses on pine. Birch leaf-mining sawfly, Fenusa pumila Klug, abundant on gray and white birch. Pavement ant, Tetramorium caespitum L., frequently a pest in houses. Cicada killer, Sphecius speciosus Drury. Chinese praying mantid, Paratenodera sinensis Sauss. In addition to these insects, about which individuals requested information regarding control methods, over 50 species of insects have been identified for amateur collectors. The Station insect collection now contains about 7,500 species. The most important recent additions have been a number of parasitic Hymenoptera and between 3,000 and 4,000 specimens of Connecticut Lepidoptera. The Lepidoptera were donated by Mr. Harry L. Johnson of South Meriden, who has so generously contributed to our collection in the past. CONFERENCE OF CONNECTICUT ENTOMOLOGISTS The seventeenth annual conference of Connecticut Entomologists was held at the Massachusetts Agricultural Experiment Station Field Station at Waltham, Massachusetts, December 13, 1940, at the invi- 298 Connecticut Experiment Station Bulletin 445 tation of Professor W. D. Whitcomb. Professor Whitcomb was elected chairman, and 50 persons registered. The program was as follows: Notes on Codling Moth and Apple Maggot in Connecticut. Philip Garman, New Haven, Conn. Notes on the Chinch Bug. J. P. Johnson, New Haven, Conn. The Place of Statistics in Entomological Research. C. I. Bliss, New Haven, Conn. Some Insect Pests of Onions in the Connecticut Valley. A. I. Bourne, Amherst, Mass. The Present Status of the European Spruce Sawfly in the United States. P. B. Dowden, New Haven, Conn. Biological Control of the Japanese Beetle. C. H. Hadley, Moorestown, N. J. HOMOPTERA OF NEW ENGLAND — A SUMMARY AND SUGGESTIONS FOR Future Inquiry. C. H. Blake, Cambridge, Mass. Cranberry Insects. H. J. Franklin, East Wareham, Mass. The Apple Leaf-Curling Midge. W. D. Whitcomb, Waltham, Mass. Inspection of Nurseries, 19 UO 299 INSPECTION OF NURSERIES, 1940 M. P. Zappe ' I 'HE annual inspection of nurseries started on July 1, 1940, as A required by Section 2136 of the General Statutes. The writer, assisted by Messrs. A. F. Clark, W. T. Rowe and R. J. Walker, inspected all the larger nurseries during July and August. The smaller ones were inspected in September, and Mr. L. A. Devaux assisted for a few days during this month. All regular inspection was completed by the end of the month. Several of the nurseries were reinspected to check on the eradication of pests. Most of the nurseries were in good condition but a few which do not carry on a very active business were rather neglected. Altogether, 96 different insect pests and 52 plant diseases were found in the nurseries during the inspection period of 1940. Most of them, however, were of minor importance. San Jose scale is very scarce at the present time, perhaps due to the fact that most of the nurseries that handle fruit stock burn up their surplus stock at the end of the selling season rather than keep it for a number of years. Spruce gall aphids were slightly more abundant than last year. European pine shoot moth continues to be a troublesome pest, especially in the southwestern part of the State. Pine leaf scale was about as abundant as last year. The presence of "X" disease of peach was detected in one block of peaches, and these trees were immediately destroyed. The stringent regulations under which peach stock is grown should completely eradicate this trouble from nur- series. Some of the more important pests that may be carried on nur- sery stock, with the number of nurseries infested by each for the past 10 years, are shown in the following table: Table 1. Ten-Year Record of Certain Nursery Pests Pest 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 Oyster-shell scale 73 68 78 104 93 87 84 53 49 57 San Jose scale 11 10 13 19 17 11 8 2 1 2 Spruce gall aphids" 124 141 231 244 285 337 306 312 216 231 White pine weevil 74 70 61 67 98 82 101 97 93 70 Pine leaf scale 20 26 46 66 42 72 60 25 50 4& European pine shoot moth .... 32 77 137 120 121 108 128 130 110 108 Poplar canker 23 40 34 39 28 28 26 20 14 15 Pine blister rust 13 12 11 7204533 Nurseries uninfested 32 24 22 21 16 26 25 32 19 33 Number of nurseries 327 351 362 381 373 380 377 402 399 376 'Includes both Adelges abietis and A. cooleyi. (3Q0 Connecticut Experiment Station Bulletin 445 Number and Size of Nurseries The list of nurserymen for 1940 contains 376 names, a decrease of 23 since 1939. A classification of nurseries by size is given in the following table. • Area Number Percentage 50; acres or more ;....... .'..•■ ..„.....;.... „. 19 5 lO. acres to 49 acres ;. 47 12 .5. acres to 9 acres 34 9 2j acres to 4 acres 94 25 Vl] acre or less ....;.' 182 49 ■ : . 376 • 100 Of the 376 nurseries listed for 1940, three new nurseries were registered and inspected before the spring shipping season and again in late summer. These are marked "(2)" after the name because each was inspected twice and was granted two certificates during the year. Thirty- four nurserymen failed to register before July 1, 1940, and, as provided by Section 2137 of the General Statutes, were charged for the cost of inspection, a minimum of $5.00 in each case. All but 10 have paid the inspection fee, and $120 has been turned over to the Treasurer of the Station to be sent to the State Treasury. The area of Connecticut nurseries receiving certificates in 1940 is 4,859 acres, an increase of 26 acres since 1939. Altogether 11 new nurseries have been added, and 34 have discontinued business either temporarily or permanently since last year. Some of these r4gistered late and were inspected but refused to pay the cost of in- spection as required by the General Statutes. Therefore, they were not issued certificates and cannot legally sell their stock. A few nur- series listed in 1939 are on the 1940 list under different names, thus changing the alphabetical arrangement. The nursery firms receiving certificates in 1940 are as follows: Connecticut Nursery Firms Certified in 1940 Name Adamcyk, Frank Adamec Evergreen Nursery, George Aldrich, Edward Aldrich, Miss Inie E. Allen, Henry L. Amato, Rose Andover Gardens Anstett Nursery, Louis Artistree Nursery Austin, Jr., Irving M. Austin, Mrs. Charles Backiel, Adolf Bailey's Nursery, Ralph Bikhmeteff, Boris A. Banak Nurseries Banigan, R. D. Certificate Address Acreage Number Deep River 1 7155 East Haven 1 6075 Guilford 1 6024 Plymouth 1 6009 Pawcatuck 1 7152 Cromwell 2 4840 Andover 1 5934 Norfolk 2 6019 Branford 3 6031 Glenville 2 6054 Yalesville 1 6031 Southport 1 6037 West Cornwall 1 5938 Brookfield 10 6047 New Britain 4 6018 Danielson 4 4837 Inspection of Nurseries, 1940 301 i- d: i.Name ■ ■• Barnes Bros. Nursery Co., The Barton Nursery Beach, Roy G. Beattie, W. H. Bedford Gardens Bedini, Vincent Beran Landscape-Developers-Florists Berg, Fred Berkshire Gate Nurseries Bertolf Brothers Biehler, Mrs. Augusta Blue Hills Nurseries, Inc. Boggini Nursery, L. Bollerer, F. G., Anderson Ave. Nursery Bonnie Brook Gardens Booy, H. W. Boschen, Goerge E. Brack Nursery Brainard Nursery & Seed Company Branford Nurseries Bretschneider, A. Bridgeport Hydraulic Company Brimfield Gardens Nursery Bristol Nurseries, Inc. Brookfield Nurseries, Inc. Brooklawn Conservatories Brooklawn Nursery Brookside Nurseries Brouwer's Nurseries Brouwer Nursery, Jack Brouwer's Nurseries, Peter Burnett's Corners Farm, The Burnside Avenue Greenhouse & Nursery Burr, Morris L. Burr & Co., Inc., C. R. Byram Nursery Candlewood Nursery Cannavo, Tony Cardarelli, E. J. Cascio Nursery, The Peter Case Company, Inc., The Centerbrook Landscape Service (2) Charlie's Stand Cherry Hill Gardens Cherry Hill Nursery, Inc. Chiapperini & Sons, Michele Child's Gardens Chippendale Nurseries, Inc. Choate School, The Chudy, Peter Clark, Arthur H. Cleary's Gardens Clinton Nurseries Clyne Nursery & Florist Coley, H. W. Compton, Margaret Conine Nursery Co., Inc. Conn. Agr. Expt. Station (W. O. Filley, Forester) Address Acreage Yalesville - ■ 200 Hamden • 1 Forestville 1 New Haven 1 Plainville 1 Ridgefield 3 New London 1 Stamford 4 Danbury 1 Old Greenwich 40 Plainville 1 Avon 30 Manchester 1 West Haven 1 Rowayton 2 Yalesville 4 West Haven 1 New Milford 3 Thompsonville 16 Branford 6 Danielson 1 Bridgeport 15 Wethersfleld 8 Bristol 65 Brookfield 3 Bridgeport 1 Bridgeport 1 Darien 5 New London 25 New London 10 New London 4 Groton 2 East Hartford 4 Westport 1 Manchester 500 East Port Chester 1 Danbury 1 Winsted 1 Cromwell 5 West Hartford 15 Ridgefield 1 Centerbrook 1 East Hartford 1 Waterbury 1 Rockfall 15 Groton 2 Kent l Old Lyme 2 Wallingford 4 Danbury 1 Yalesville 1 Bethel 1 Clinton 60 Milldale 1 Westport 1 Norwalk 2 Stratford 75 New Haven 2 Certificate Number 5922 7199 4836 7159 6034 7126 7181 7125 4842 5953 6051 4887 6042 6096 6014 6039 7142 5930 4899 7190 6030 5961 6027 4841 7189 5915 7166 4892 5964 6081 6073 4855 6000 6059 7111 7198 5949 4880 4872 5917 4869 5960 7185 4831 5987 6089 4868 7140 6044 7153 7148 7106 4867 5972 7192 7171 5967 5973 302 Connecticut Experiment Station Bulletin 445 Name Address Connecticut Forestry Nurseries Deep River Connecticut State Forestry Dept. Hartford Connecticut State Highway Dept. Hartford Connecticut Valley Nurseries Manchester Cooke, C. W. Branford Cronamere Alpine Nurseries, Inc. Greens Farms Cylkowski, B. Simsbury Daisy Hill Gardens Derby Damen, Peter J. East Haven Daniel, Joseph Bridgeport Davis Gardens Ansonia Daybreak Nurseries Westport DeMars Nursery Winsted Dewey, V. E. Groton Dietrich Nursery, Benjamin Greenwich Dillon, Thomas Greenwich Dingwall, Joseph N. West Haven Doane, David F. Haddam Dobel, Paul Union City Donovan, Daniel Talcottville Donovan, John N. Rocky Hill Drenckhahn, Ernest J. Cos Cob Dunlap's Dollar Evergreens Cromwell Dunn, John Danbury Eager, Edward M. Bridgeport East Haven Nursery East Haven Elfgren Nurseries East Killingly Ellington Evergreen Nursery Ellington Elliott, Jesse M. & Grace E. Litchfield Ellmer, Karl Cannondale Ellsworth Nursery Newington Elm Grove Cemetery Association Mystic Evergreen Nursery Co., The Wilton Fairlawn Nurseries Darien Fairway Gardens Woodmont Farmington Valley Nursery Avon Ferchau, Hugo Milford Ferruci, Joseph Bridgeport Flower City Rose Company Manchester Follett Nursery Westport Forbes Street Greenhouse East Hartford Fountain Nurseries Farmington Foxon Park Nursery East Haven Frank & MacArthur Ansonia Fraser's Nurseries & Dahlia Gardens Willimantic Frede, Wm. Frederick Danbury Galligan, Clarence W. New Haven Garden Exchange, The Bridgeport Garden of Romance, The Old Savbrook Gardner's Nurseries Rocky Hill Geduldig's Florist & Nurseryman Norwich George's Hill Nursery Southbury German, Peter B. Fairfield Giana, John F. Kensington Giant Valley Nursery Mount Carmel Glastonbury Gardens Glastonbury Gledhill Landscape & Tree Service West Hartford Glenbrook Greenhouses Glenbrook Glen Echo Farm Bridgeport Certificate Acreage Number 15 7143 8 5998 18 7119 39 7112 1 5955 5 5923 2 5944 1 4889 2 4850 1 5916 1 5900 3 7202 1 4885 2 7204 4 5978 1 7135 1 7186 1 7133 1 7196 1 5926 3 6010 10 7208 3 7164 1 6005 1 4849 1 5969 3 5925 2 7178 1 7109 5 7139 1 7151 1 5997 30 4883 8 7177 1 7120 5 7123 2 7100 1 7209 23 7113 10 6057 1 7207 10 6066 1 4886 1 7105 3 5975 1 5939 1 7145 1 7183 3 7195 300 5914 7 7124 1 7130 1 7157 1 4848 1 6098 4 4882 1 7205 1 4854 1 4830 Inspection of Nurseries, 19 W 303 Name Glen Terrace Nurseries Glenwood Nurseries Godfrey, George R., Stratfield Nursery Godfrey Tree Expert Co. & Garden Shop Golden Hill Nurseries Goodwin Nurseries Goshen Nurseries Gosnell, Evelyn Great Pond Nursery Green Acre Farms, Inc. Grillo, N Gunn, Mrs. Charles Haas, Florist Hamden Nursery Hansen's Florist £> Nursery Hansen's Garden Hearn, Thomas H. Heath & Company Henninger, Christ. Hettinger, Joseph O. Hildebrand's Nursery Hilding Brothers Hillcrest Gardens Hilliard, H. J. Hilltop Nurseries Hinckley Hill Nurseries Hiti Nurseries Hoffmann's Nursery Hofmann, William T. Holcomb's Evergreen Nursery Holdridge & Sons, S. E. Hope Street Nursery Horan, J. F. Horan, Kieran W. Horowitz, Ben Hosking, James S. Hotchkiss, H. L. Hotchkiss, Sr., Wallace M. Houston's Nurseries Hoyt, Charles E. Hoyt's Sons Co., Inc., Stephen Hurlburt Nursery Hutt, Robert F. Hyatt, Thaddeus Isselee's Sons, Inc., Charles Jennings, Sereno G. Johnson, Lincoln Johnson, Tom Joyosa Gardens Kateley, Milton M. Kelley & Son, James J. Kellner, Arthur H. Kennedy, Wellington Keso Nursery Key Rock Gardens Knobling, Edmund Certificate Address Acreage Number Hamden 70 4858 Clinton 2 6048 Bridgeport 50 5919 Fairfield 1 5996 Shelton 2 5948 Bloomfield 13 5937 Goshen 6 7203 Westport 1 6067 Hartford 1 4857 Waterford 1 6008 Milldale 1 4856 Kent 1 7129 Milford 1 4846 Hamden 1 7138 Fairfield 5 7167 Newington 2 7122 Washington 3 7146 Manchester 15 7114 New Britain 1 6063 Manchester 1 7117 Norwich 1 4893 Amston 1 6094 Woodbridge 4 5962 Sound View 1 5999 Orange 1 4845 Stoning ton 1 6074 Pomfret Center 11 4874 Hartford 2 7107 Cromwell 3 6056 Winsted 6 4865 Norwich 3 6023 Springdale 1 7188 Hartford 1 7104 West Hartford 1 7210 East Hampton 1 6087 Watertown 2 5947 North Haven 1 7184 Norfolk 1 6071 Mansfield Depot 5 6040 Bethel 40 6011 New Canaan 500 4864 Hamden 1 6082 Glastonbury 3 6090 Stamford 3 7213 Darien 5 5911 South port 2 6001 Stamford 15 5929 Stratford 1 6077 Cornwall Bridge 1 4863 East River 1 4862 New Canaan 6 5909 Norwalk 1 6032 Greenwich 20 7154 Clinton 1 7194 Newtown 2 6061 Danbury 3 6017 304 Connecticut Experiment Station Bulletin 445 Name LaBell, Harold (2) Lanedale Farm Nurseries Langstroth Nurseries Laviola & Sons Leghorn's Evergreen Nursery Leramon, Robert S. Lewis & Valentine Landscape Corp. Lewis Gardening Service Lipari, V. Lovely Garden Lowescroft Gardens Luce, Mrs. Charles L. Luckey, Ada Mae Luckner, Jr., William Lynch, Mrs. John H. Marigold Farm Marlboro Nurseries Mather Homestead McCarthy, John P. McConville's Greenhouses & Nurseries Meier, A. R. Melville Nurseries Merwin Lane Nursery Meyer Nursery, Ludwig Middeleer Midway Nurseries (2) Milford Nursery Millane Nurseries & Tree Experts, Inc. Mill River Nursery Millstone Garden Montgomery Ward & Company Moore Hill Nurseries Moraio Bros. Morgan, Everett E. Morgan & Sons, Wm. F. Mountain Grove Cemetery Association, The Mount Carmel Nursery Mount Phillip Nursery Munro, Edward A. New England Water Lily Gardens New Era Seed Company New Haven Park Commission New Haven Park Department, Bureau of Trees Newington Gardens & Nurseries New London Cemetery Association New London County Nurseries Newton's Nursery New York, New Haven & Hartford Railroad Niantic Bouquet Shop North-Eastern Forestry Co., The North Greenwich Nursery North Street Gardens Northville Gardens Norwalk Perennial Garden Nyveldt's Nursery Oakland Nurseries Oldfield Nursery Certificate Address Acreage Number East Haven 5 7110 New Canaan 10 6007 Danbury New Haven 6 2 5968 7180 Cromwell 40 6095 New Canaan 1 7173 Darien 9 5991 Kensington Bridgeport Unionville 3 4861 7201 7127 Manchester 7102 Newington Greens Farms 7175 6036 Stepney Ridgefield 3 6038 5984 New Canaan 20 5983 East Hampton Darien 2 2 6070 4859 Danbury Manchester 2 4 5971 5908 West Hartford 1 5956 Bridgeport East Norwalk 1 3 6002 5931 Bridgeport Darien 5 10 5928 6076 New Haven 10 7168 Milford 2 7136 Cromwell 100 4844 Fairfield 8 4898 Terryville Manchester 1 5 6099 7172 New London 2 6029 Old Greenwich 5 5986 Stonington North Stonington 1 2 5924 6072 Bridgeport Mount Carmel 1 1 4894 7141 Weatogue New Haven 2 1 7206 5903 Manchester 1 4860 Clinton 2 5901 New Haven 6 4847 New Haven 7 6045 Hartford 1 7197 New London 1 7179 New London 10 5935 West Granby 1 7150 Stamford 3 4843 Niantic 1 7163 Cheshire 96 4895 Greenwich 1 5995 Milford 1 • 7160 New Milford 1 6092 Norwalk 4 4891 New London 3 5945 Manchester 20 7115 Stratford 1 7211 Inspection of Nurseries, 191+0 305 Name Outpost Nurseries, Inc. Ouwerkerk, Dirk K. Over-the-Garden-Wall Oxoboxo Nursery Palmieri Nursery & Florist Parker, Mrs. Elizabeth Partrick Nursery Pendleton's Flower Gardens Pestretto, Frank Pestretto, Salvatore Peterson's Flower Shop Pierson, Inc., A. N. Pinchbeck Brothers, Inc. Pine Hirst Gardens Pine Plains Greenhouses Piatt, Kenneth M. & Norman E. Pleasure Gardens Polen, Romuald Polish Orphanage Farm Pomeroy Nurseries Prospect Nurseries, Inc. Q Garden Farms Nursery Rabinak Flower Farm Race Brook Gardens Reliable Nursery, The Rengerman's Garden Reveley Landscaping Service, The Reynolds' Farms Richmond, Gordon L. Ridgewood Nurseries Riese, F. K. Riverside Farm Robinson Estate, Seymour N. Rockacres Nursery Rockfall Nursery Company, The Rose Hill Nursery Russell Street Perennial Garden Sage Brothers Sakson's Nursery Sandelli Greenhouses Sasco Hill Nursery Savanella Brothers Nursery Scarano Nursery, Alphonse Schleichert Nursery Schmidt, Walter A. Schneider, Adolf Schuller, John Schulze, Edward E. Scott's Nurseries Scotty's Landscape Service Sears, Roebuck & Company Seltsam's Pequonnock Gardens Seymour Garden, Prudence Sharon Valley Nursery Silver City Nursery Silver Lane Nursery Simonsen, H. C. Sipocz Arrowhead Farm Certificate Address Acreage Number Ridgefield 700 4888 Yalesville 10 5941 West Hartford 3 6006 Montville 2 6055 New Haven 1 4839 Bridgeport 4 5982 Sandy Hook 1 7101 Norwich 1 5989 West Hartford 1 7176 Hartford 1 7170 West Hartford 1 7174 Cromwell 300 5951 Ridgefield 10 6088 Guilford 1 6043 Norwich 2 7193 Milford 1 5993 Guilford 1 4866 Southport 2 6026 New Britain 1 6062 New Milford 1 6020 Cromwell 30 5976 Milford 1 4875 Deep River 4 5940 Orange 1 4838 East Hartford 2 6021 Granby 2 5920 Clinton 1 5965 South Norwalk 2 4870 New Milford 10 4876 Milford 1 5907 Watertown 1 7134 Milford 1 6012 West Hartford 2 6093 Stamford 2 5990 Rockfall 10 5980 Gildersleeve 3 7118 South Manchester 1 5952 Woodbury 1 7137 Greenwich 1 6060 New Britain 1 5921 Fairfield 1 5988 Torrington 2 7169 Groton 1 4871 Bridgeport 4 5966 East Glastonbury 1 7200 Milford 1 6078 Higganum 4 6097 Bethel 1 7165 Bloomfleld 10 6064 Woodbury 1 6004 Manchester 10 7116 Bridgeport I 4873 New Milford "T 4853 Sharon 1 5932 Meriden 6 7131 East Hartford 1 7191 Plainville 2 6085 Fairfield 1 4884 306 Connecticut Experiment Station Bulletin 445 Name Smith, Edward A. Soltes Nursery, M. }. Southbury Nursery, The Southington Nursery Southport Nursery South Wilton Nurseries Stafford Conservatories Standish, Norman S. Stannard, Julia State Street Nursery Steck, Charles A. Steck Nursery Steele's Nurseries, Charles Stocking, Milton C. Sunny Valley Nursery Sunridge Nurseries Sun Rise Nursery Swendson, Hans Sylvan Greenhouse & Nursery Taylor, Walter G. Thomson Company, W. W. Tobin, Daniel J. Tollgate Nursery Torizzo, P. A. Tow Path Gardens, Inc. Tracy, B. Hammond Triangle Nursery Twin Pines Gardens University of Connecticut Valentine, William Valley View Nursery van der Bom, Mrs. F. Vanderbrook & Son, C. L. Van Horn & Harrington Van Wilgen, Wm. Van Wilgen Nurseries Vasileff Nurseries Verkade's Nurseries Vernick's Nurseries & Landscape Service Wagner, William H. Wallace Nursery Wallingford Nurseries Ward & Son, J. F. Watertown Nurseries Wayside Garden Wayside Nursery Weinberger, William West Cornwall Nurseries Westerly Nurseries West Mystic Gardens Westover Trading Corp. Westville Nurseries Wethersfleld Nursery Wheeler, Charles B. Whipple, Earle G. Whittemore Company, J. H. Wildflower Nurserv, The Wild's Nursery, Henry Certificate Address Acreage Number Mystic 1 4833 Shelton 2 4897 Southbury 4 6028 Southington 15 6016 Southport 35 5906 Wilton 9 4877 Stafford Springs 1 5904 Hanover 1 6091 Wilton 1 7149 Hamden 5 6049 Newtown 20 5913 Bethel 4 6046 Greenwich 3 5933 Avon 1 6053 New Milford 15 4878 Greenwich 55 7156 North Haven 1 4835 Cheshire 1 5902 Bridgeport 1 6068 Wallingford 1 6050 West Hartford 4 5977 Ridgefield 2 4834 Avon 1 5942 West Hartford 5 5957 Hartford 5 5918 West Hartford 1 7214 Yalesville 2 5992 New Milford 1 6035 Storrs 1 5981 Pomfret Center 1 6033 Southington 1 6052 Bethel 5 7121 Manchester 60 4881 Suffield 1 6084 Branford 1 6025 Branford 22 5912 Greenwich 6 6079 New London 60 5974 Bridgeport 2 5994 Woodbury 1 5946 Wallingford 2 6015 Wallingford 75 5950 Windsor 1 5927 Watertown 1 7158 Canton 1 5936 Naugatuck 2 5979 Ridgefield 1 5910 West Cornwall 1 5943 Pawcatuck 2 6058 West Mystic 1 5985 Stamford 1 5954 Westville 2 4832 Wethersfleld 3 6083 Stonington 1 6086 Danielson 1 7132 Naugatuck 3 5970 Brookfleld 1 7108 Norwalk 23 4890 Inspection of Nurseries, 19 AO 307 Name Willow Gardens Willson, Stewart H. Wilridge Nurseries Wilson, M. L. Wilson Nurseries, C. E. Wilson Landscape Company, The Woodbridge Nurseries Woodcrythe Nursery (W. S. Sloan) Woodmont Nurseries Wyllie, David Yale University School of Forestry Nursery Yale University Landscape Dept. Young's Nurseries Zack Company, H. J. Total Certificate Address Acreage Number Darien 1 6003 Thompsonville 1 7212 Ridgefield 5 7128 Litchfield 5 6013 Manchester 75 6041 Hartford 1 5958 New Haven 15 4896 New Canaan 1 7162 Woodmont 60 4879 North Haven 1 7147 New Haven 1 7161 New Haven 10 4851 Wilton 4 5963 Deep River 10 7144 376 nurseries 4,859 acres The cost of inspecting these nurseries, including certain addi- tional visits to make sure that the pests had been properly eradi- cated, was approximately $1,835.65, exclusive of traveling expenses. Other Kinds of Certificates Issued During 1940, 208 duplicate certificates were issued to Connecti- cut nurseries to be filed in other states. One hundred and two dealers permits were issued to dealers, who do not grow the nursery stock which they sell. All this stock is purchased from certified nurseries for resale. Shippers' permits to the number of 264 were issued to out-of-state nurserymen who wished to ship stock into Connecticut. Also, 212 parcels of nursery stock and other plant material were inspected and certified for shipment to accommodate individuals. There were also issued 208 miscellaneous certificates and special permits. 173 blister rust control area permits. 1.051 corn borer cer- tificates, and 3.665 certificates for packages of shelled corn and other seeds, most of which were consigned to foreign countries. Inspection of Imported Nursery Stock Foreign nursery stock enters the United States at designated ports of entry under permits issued by the Federal Bureau of Ento- mology and Plant Quarantine and is released for transit to destina- tion points, where it is examined by State inspectors. Importation permits are usually granted for rose stocks only. These stocks are used almost entirely by florists for grafting purposes. The number of shipments of imported rose stocks entering Connecticut from for- eign countries was less during 1939-1940 than in the previous year. Rose stocks are now being grown in larger amounts in the United States and less foreign material is coming into the State. Six ship- ments containing 29 cases and 239,400 rose plants, all of which were for propagation purposes, were imported. All of them were Rosa 308 Connecticut Experiment Station Bulletin 445 manetti. These plants were all imported by three commercial rose growers who received 164,400, 40,000, and 35,000, respectively. They came from the following sources: Country No. shipments No. -'plants Holland 5 199,400 England 1 40,000 The time required to inspect this rose stock was equivalent to four days' work for one man and this, together with travel (320 miles) and other necessary expenses, amounted to a cost of approximately $56. Reports of the results of inspection of the six shipments were sent to the Federal Bureau of Entomology and Plant Quarantine. Of the six shipments inspected, only one was found infested with larvae of a sawfly, Emphytus cinctus Linn., which enters the pith of the cut stems seeking a place to pupate. No crown gall, a bacterial disease, was found. In addition to the rose stocks mentioned above, the following miscellaneous plants and seeds entered Connecticut after Federal inspection at ports of entry. None of these was inspected in Con- necticut. This material is allowed entry into the United States in small lots under a special permit issued by the Bureau of Entomology and Plant Quarantine, and is sent to Washington, D.C., for inspec- tion. 7,796 orchid plants 24 rose plants 2,794 pounds of seeds 5 holly plants 46 dahlia tubers 15 English walnut trees 66 iris plants 2 spruce trees 135 perennials 2 lilac bushes 9,450 gladiolus JAPANESE BEETLE QUARANTINE ACTIVITIES, 1940 M. P. Zappe Since the establishment of the Japanese beetle quarantine in Connecticut, the Department of Entomology of the Connecticut Agri- cultural Experiment Station has cooperated with the Bureau of Ento- mology and Plant Quarantine of the United States Department of Agriculture in administering this quarantine. The work consists of seasonal scouting of certain nursery and greenhouse properties and their sources of sand, soil and manure for classification purposes; the inspection and certification of all articles included in the quaran- tine regulations; and other tasks necessary to the operation of the quarantine. The State is divided into two sections, using the gypsy moth quarantine line as a boundary. That section of the State within the gypsy moth quarantined area, which includes Hartford, Middlesex, New London, Tolland and some towns in eastern Litchfield and New Haven counties, is under the supervision of Mr. H. N. Bartley, in charge of the Federal Japanese beetle office at Waltham, Mass. His inspectors make the necessary inspections to comply with the ,'.;•-.; '. Japanese Quarantine Activities, 1940 309 Japanese beetle and gypsy moth quarantines, and European corn borer inspections as required by certain states. In the rest of the State the inspections are made from the New Haven office at the Experiment Station. During the rush of the shipping season in the spring, when Mr, Bartley's inspectors are very busy, the towns of Branford and North Haven are often placed under the supervision of the New Haven office. Scouting Scouting for the Japanese beetle has been conducted yearly, and the procedure followed during the summer of 1940 to determine whether or not adult beetles were present on classified properties was similar to that of preceding years. Three crews were used to carry on this work, two of which were under the supervision of the Waltham office, each consisting of one foreman and two scouts. They began scouting on July 9 and finished on August 31. The third crew, consisting of one foreman and one scout, under the super- vision of the New Haven office, began on July 15 and finished on September 6. Each crew followed a prepared itinerary as in pre- vious seasons. They scouted 33 nursery, greenhouse or other similar establishments and their subdivisions, a total of 66 units, three to five times. The minimum distance examined around each establishment was 500 feet. A total of 887 adult beetles was found on or within 500 feet on 31 of the units scouted. The crews also scouted the premises of 21 dealers in sand, soil and manure and found one beetle on one of these establishments. The finding of infestations on scouted premises resulted in 10 changes in classification and 22 estab- lishments dropping their classified status under the quarantine regu- lations. Beetles were found in Orange, Middlefield and Woodbridge for the first time. There are 83 towns now known to be infested and probably many others that have not come to our attention. Inspection and Certification The district inspectors are responsible for the inspection and certification of quarantined materials on account of the gypsy moth and Japanese beetle quarantines. The following is a list of these men and the towns in which they make inspections: R. L. Emrick, Box 63, Sta. A, Manchester. Telephone Manchester 4482. Avon Enfield Stafford Barkhamsted Farmington Suffield Bloomfield Granby Tolland Bolton Hartford Torrington Burlington Hartland Union Canton Harwinton Vernon Colebrook Manchester West Hartford Coventry Mansfield Willington East Granby New Hartford Winchester East Hartford Simsbury Windsor East Windsor Somers Windsor Locks Ellington South Windsor 310 Connecticut Experiment Station Bulletin 445 J. F. McDevitt, Box 45, Andover Berlin Branford Bristol Chester Clinton Colchester Columbia Cromwell Durham East Haddam East Hampton Essex Glastonbury Middletown. Telephone Guilford Haddam Hebron Killingworth Lebanon Madison Marlborough Meriden Middlefield Middletown New Britain Newington North Branford North Haven Middletown 1 61 3. Old Saybrook Plainville Plymouth Portland Rocky Hill Saybrook Southington Thomaston Waterbury Westbrook Wethersfield Wolcott Daniel Harrington, Ashford Bozrah Brooklyn Canterbury Chaplin Eastford East Lyme Franklin Griswold Groton Hampton Killingly Box 63, Westerly, R.I. Telephone Westerly 2604. Ledyard Lisbon Lyme Montville New London North Stonington Norwich Old Lyme Plainfield Pomfret Preston Putnam Salem Scotland Sprague Sterling Stonington Thompson Voluntown Waterford Windham Woodstock L. A. Devaux and A. S. Beecher, Box 1106, New Haven. Telephone New Haven 5-6191. All towns not listed above. The total number of plants inspected and certified for shipment to other states and foreign countries was 7,308,128. The number and kinds of certificates issued are shown in the following table: Table 2. Number of Certificates Issued, 1940 Kind Farm Pn aducts Cut Flowers Nursery and Ornamental Stock Sand Soil Manure Total "A" "B" 0 0 0 28 0 28 38,188 7,839 2 0 2 0 1 1 38,218 7,840 Total 46,027 46,058 As in past seasons, the district inspectors were able to make the necessary farm products quarantine inspections in addition to their regular duties. These were few in number and consisted of 28 boxes of cut flowers. No inspections were made of farm products material because the Town of Greenwich was the only town in the State where such inspections were required and no shipments were made therefrom. INSPECTION OF APIARIES, 1940 M. P. Zappe Mr. H. W. Coley, who had been the bee inspector in Fair- field, New Haven, Middlesex and New London counties, retired Inspection of Apiaries, 1940 311 from service in 1940 and Mr. Roy Stadel of Southington was appointed on April 15, 1940, to inspect bees in the above mentioned parts of the State. Mr. H. W. Kelsey of Bristol inspected bees in the four northern counties. A total of 1,719 apiaries containing 8,552 colonies were in- spected in 1940. These averaged 5.0 colonies per apiary, as against 5.5 in 1939. There were 366 colonies in 161 apiaries infected with American foul brood, a considerable increase over the number found in 1939. Most of this increase occurred in the four southern coun- ties. Several of the apiaries were inspected twice, as in order to burn the diseased colonies it was necessary for the inspectors to make a second visit to these apiaries. Only one colony was found infected with sacbrood. Table 3. Thirty-One Year Record of Apiary Inspection Average Average Number Number No. colonies cost of inspection Year apiaries colonies per apiary per apiary per colony 1910 208 1,595 7.6 $2.40 .28 1911 162 1,571 9.7 1.99 .21 1912 153 1,431 9.3 1.96 .21 1913 189 1,500 7.9 1.63 .21 1914 463 3,882 8.38 1.62 .19 1915 494 4,241 8.58 1.51 .175 1916 467 3,898 8.34 1.61 .19 1917 473 4,506 9.52 1.58 .166 1918 395 3,047 7.8 1.97 .25 1919 723 6,070 11.2 2.45 .29 1920 762 4.797 6.5 2.565 .41 1921 751 6,972 9.2 2.638 .24 1922 797 8,007 10.04 2.60 .257 1923 725 6.802 9.38 2.55 .27 1924 953 8,929 9.4 2.42 .25 1925 766 8,257 10.7 2.45 .22 1926 814 7,923 9.7 2.35 .24 1927 803 8,133 10.1 2.37 .234 1928 852 8,023 9.41 2.12 .225 1929 990 9,559 9.55 2.19 .227 1930 1,059 10,335 9.76 2.01 .206 1931 1,232 10,678 8.66 1.83 .212 1932 1.397 11,459 8.2 1.60 .195 1933 1,342 10,927 8.1 1.69 .208 1934 1,429 7,128 4.98 1.40 .28 1935 1,333 8,855 6.64 1.556 .234 1936 1,438 9,278 6.45 1.429 .221 1937 1,437 10,253 7.1 1.28 .18 1938 1,609 10,705 6.7 1.18 .177 1939 1,627 8,936 5.5 1.12 .204 1940 1,719 8,552 5.0 1.33 .268 Table 3 shows the number of apiaries and colonies inspected, the average number of colonies per apiary, and the average cost of inspecting each apiary and colony for each year since inspection began in 1910. 312 Connecticut Experiment Station Bulletin 445 In 1940 apiaries were inspected in 143 towns. No inspections were made in the following 26 towns owing to shortage of time and money: Bridgeport, Canaan, Chester, Columbia, Darien, Franklin, Griswold, Groton, Killingworth, Lebanon, Ledyard, Lyme, Madison, Manchester, New Haven, North Stonington, Norwalk, Old Lyme, Saybrook, Sprague, Stafford, Union, Voluntown, Westbrook, West Haven, and Weston. American foul brood was discovered in the following 76 towns: Fairfield County: Bethel, Brookfield, Danbury, Greenwich, Monroe, New Canaan, New Fairfield, Newtown, Redding, Ridgefield, Shelton, Sherman, Stamford, Wilton. New Haven County: Beacon Falls, Branford, Cheshire, Derby, East Haven, Guilford, Hamden, Meriden, Middlebury, Milford, Nau- gatuck, North Branford, North Haven, Orange, Oxford, Prospect, Seymour, Southbury, Wallingford, Woodbridge, Wolcott. Middlesex County: Durham, East Hampton, Middlefield, Middle- town. New London County: East Lyme, Colchester, Lisbon, Montville, Norwich, Preston, Stonington, Waterford. Litchfield County: Bethlehem, Bridgewater, Harwinton, Litchfield, Morris, Plymouth, Salisbury, Torrington, Washington, Watertown. Hartford County: Berlin, Bloomfield, Bristol, East Hartford, East Windsor, Farmington, New Britain, Simsbury, Southington, West Hartford, Windsor. Tolland County: Coventry, Ellington, Somers, Stafford, Tolland, Vernon. Windham County: Ashford, Windham. Statistics of Inspection The statistics of apiary inspection are given below. Table 4. Inspection of Apiaries, 1940 Number of Apiaries Colonies County towns Inspected Diseased (Am. f. b.) Inspected Diseased (Am. f. b.) Fairfield 18 199 45 1,121 106 New Haven 25 238 46 1,385 130 Middlesex 10 98 7 682 8 New London 11 95 16 643 44 Litchfield 25 296 16 1,321 24 Hartford 28 472 20 2,315 34 Tolland 11 169 7 467 15 Windham 15 143 152 4 161 618 5 1,719 8,552 366 Report on the Gypsy Moth, 1939-1940 Summary of Inspection 313 Apiaries Colonies Inspected, 1940 1,719 8,552 Infected with American foul brood 161 366 Percentage infected 9.4 4.3 Colonies treated 14 Colonies destroyed 352 Average number of colonies per apiary 5.0 Average cost of inspection $1.33 $ .268 Total cost of inspection, 1940 $2,291.95 Financial Statement January 1, 1940 — December 31, 1940 Disbursements January 1 to June 30, 1940: Salaries $582.00 Travel (outlying investigations) 458.60 $1,040.60 July 1 to December 31, 1940: Salaries $702.00 Travel (outlying investigations) 549.35 1,251.35 Total disbursements for 1940 ■. $2,291.95 Registration of Bees Section 2129 of the General Statutes provides: That each bee- keeper shall register his bees on or before October 1 of each year with the town clerk of the town in which the bees are kept; and that each town clerk, on or before December 1, shall report to the State Entomologist whether or not any bees have been registered, and if so, shall send a list of the names and number of colonies belonging to each. In 1940, 1,719 apiaries containing 8,552 colonies were inspected. However, only 904 apiaries and 6,117 colonies were registered. After checking the registrations and inspections, and deducting duplications, the following figures were obtained show- ing that at least this number of apiaries and colonies were kept in Connecticut in 1940. Apiaries Inspected 1,719 Registered but not inspected 60 1,779 Colonies 8,552 428 8,980 REPORT ON THE GYPSY MOTH, 1939-1940 R. B. Friend, J. T. Ashworth and 0. B. Cooke Introduction The gypsy moth is the most serious insect pest of hardwood trees in the State. Unfortunately it attacks some of our most use- 314 Connecticut Experiment Station Bulletin 445 ful and abundant species. Although all trees attacked during an outbreak do not die, a severe retardation of growth follows defoli- ation, which means a decrease in the production of wood. More- over, defoliated trees markedly lessen the attractiveness of the recre- ational areas in the State. This insect is now firmly established in Connecticut and occurs in greater or less abundance over much of its area. The prospect of eliminating it from the entire State is too remote for practical consideration, so our main concern is to prevent serious injury to our forests and shade trees. In order to accomplish this it is necessary to prevent the development of out- breaks, during which the trees may be stripped of foliage for two or more successive years. The prevention of outbreaks is based on a knowledge of the insect and of the effect of environment factors on its activities and abundance, a thorough understanding of the effect of the insect on trees under various growing conditions, and on efficient control methods. Since control work started with the discovery of the gypsy moth in the State in 1906, only three serious outbreaks have oc- curred. The largest of these, involving about 1,500 acres in the towns of Granby, Canton, and Simsbury in 1938 and 1939, has been described in the two previous reports of this office. Although the insect has increased in abundance in many towns during the last few years, an attempt is being made to handle the situation without increasing the personnel involved. Work now being carried out by this department, by investigators in other states, and by the Federal Bureau of Entomology and Plant Quarantine should be of distinct aid in increasing the efficiency of operations. Gypsy moth control work has been carried on during the past year (1939-1940) in much the same manner as in previous years. During the fall, winter and early spring, trees are inspected for egg-masses. These egg-masses are destroyed when found. During the late spring and early summer, the larger infestations are sprayed to reduce or possibly eradicate them. During the summer months, areas infested with the gypsy moth are patrolled to detect gypsy moth caterpillars. With the cooperation of the United States Bu- reau of Entomology and Plant Quarantine, and the C.C.C., control work in one form or another was performed in 59 towns in all sections of the State during the past year. To the following persons the writers here express thanks for their hearty cooperation: Mr. A. F. Burgess, who has general su- pervision of gypsy moth and brown tail moth control for the Federal Bureau of Entomology and Plant Quarantine; Mr. H. L. Blaisdell. in charge of field work under Mr. Burgess; Mr. S. S. Crossman, under whose direction gypsy moth control work was carried on in the various C.C.C. camps in the central section of the State; and to Mr. A. F. Hawes, State Forester, who has general supervision of the C.C.C. camps. Report on the Gypsy Moth, 1939-1940 315 New Equipment Just prior to the spraying season, one length of suction hose was purchased to replace a length that had become worn out, and considerable repair work, which was badly needed, was done on the two sprayer pumps, putting them in good condition. There was no replacement of department vehicles during the past year. The usual number of small wrenches and other tools that had become worn out or broken were replaced. Control Operations Following is a brief report of gypsy moth control operations carried on by the different agencies during the past year. Work Performed by State Men The regular state gypsy moth crews operated in Windham, New London, Tolland. Hartford and Litchfield counties. Windham County: Scouting work was performed in the towns of Brooklyn. Killingly and Plainfield. Gypsy moth infesta- tions were found in all towns visited. No other type of control work was performed in this County. New London County: The towns of Colchester, East Lyme. Groton, Lisbon, Montville, New London, North Stonington. Old Lyme and Stonington were visited, gypsy moth egg-masses or larvae (caterpillars) being found in all of them. There was no spraying work carried on in the County. Tolland County: Two towns, Stafford and Union, were in- spected and gypsy moth infestations were found in both. No spray- ing or patrolling (larvae) work was carried on in this County. Hartford County: Gypsy moth control work in the form of scouting or patrolling for larvae was performed in the towns of Bloomfield, East Granby, Enfield, Granby, Hartford, Manchester, Simsbury, South Windsor and West Hartford, egg-masses being found and larvae taken in all towns visited with the exception of Hartford. Only a small section in the northern part of Hartford was scouted, and this mainly because it was adjacent to infested territory in the town of Bloomfield. Hence this does not indicate that Hartford is free from gypsy moth infestation. Litchfield County: Two towns were scouted during the past season, gypsy moth infestations being found in both. There was no spray work performed in the County by state crews this season. There was no gypsy moth control work carried on in Middle- sex, New Haven and Fairfield counties, by state crews in the past year. During the year, state men scouted 304 miles of roadside, 1,493 acres of woodland and open country, and destroyed 26,320 egg-masses and 19,722 larvae and pupae. 316 Connecticut Experiment Station . Bulletin 445 During the month of September, 1939, some of the crews were started on a type-mapping project, and, coincidentally, a survey to determine the density of the gypsy moth population in the towns that were being type-mapped. The type-mapping consisted of a' survey of the wooded and open areas of a town to determine the percentage of favored and unfavored food plants of gypsy moth lar- vae. This information is placed on outline maps of the towns, using different colors to indicate the different percentages of favored food plants in each block. These maps, together with the data received from the survey made to determine the density of gypsy moth pop- ulation in the same town, are filed, and it is expected that frequent study of this information will enable us to anticipate where the greatest increase in the gypsy moth is likely to occur, and, by peri- odic inspection of the most dangerous areas, to prevent the gypsy moth infestations in these areas from reaching the stage where large areas of woodland are defoliated. It will also be the means of en- abling a small force, such as we have at the present time, to cover, in one season, a much larger portion of the State than has been done previously. This work was carried on in the towns of Brooklyn, Groton, Killingly, North Stonington, Plainfield, Pomfret, Stonington, Thompson, and Woodstock, during the past year. During the spraying season, state men were engaged in control operations at a large infestation at "West Peak", Meriden, and a large infested area, located in the towns of Granby, Simsbury and Canton, previously reported in 1938-1939. Again this year, it was necessary for the State to obtain the loan of spraying equip- ment from the Federal Bureau of Entomology and Plant Quar- antine and to secure the use of C.C.C. men to assist in the spray- ing operations. Due to the size of the area involved at the Granby- Simsbury-Canton infestation, and the time available to complete the work, four power spraying machines, working two shifts a day, were used. This operation required the use of approximately 120 C.C.C. men and all available state men each day. Smaller infested areas in the towns of Barkhamsted, Berlin, Burlington, and Hart- land were also sprayed. Altogether 1,574 acres of woodland were sprayed and 43,786 pounds of arsenate of lead used. For the first time in Connecticut, an autogiro was used to dust two plots, 461 -acre total, in the Granby-Simsbury-Canton area during the past spraying season. This autogiro, the property of the U. S. D. A., Bureau of Entomology and Plant Quarantine* is equipped with special apparatus which enables it to fly over a Report on the Gypsy Moth, 1939-19W 317 marked area and expel a mixture of arsenate of lead and fish oil on the foliage much more quickly and with much less effort than can be accomplished with a ground spraying machine. A more complete report of the dusting by autogiro will be published when all the data have been compiled and analyzed. Work Performed by COG. Men During the past season, details of men from the C.C.C. camps located in the central part of the State performed gypsy moth con- trol work in the following towns: Durham and Middletown in Middlesex County; Berlin, Burlington, Canton, Granby, Hartland. Simsbury, and Southington in Hartford County; Branford, Guilford and Meriden in New Haven County; and Barkhamsted, New Hart- ford and Winchester in Litchfield County. This control work con- sisted of scouting, thinning, and spraying. During the course of the work year they creosoted 862,299 egg-masses, destroyed 10,426 lar- vae and pupae, scouted 129 miles of roadside and 51,494 acres of woodland. Work Performed by W.P.A. A gypsy moth control project financed by funds furnished by the Works Progress Administration and supervised by the U. S. D. A., Bureau of Entomology and Plant Quarantine, was carried on in the western part of the State in Hartford, New Haven and Litchfield counties. With the exception of a small supervisory force, all the labor employed on this project was received from the relief rolls of the towns in the vicinity of which control work was carried on. Control work in the form of scouting, thinning, banding and spray- ing was performed in 23 towns in these three counties, during the course of which 30,236 egg-masses were found and destroyed, 119,513 larvae and pupae were destroyed, and 346 miles of roadside and 85,799 acres of open and wooded country scouted. During the spraying season, 21 infestations were sprayed, 71,537 pounds of arsenate of lead being used during the operations. Scouting for Brown-Tail Moth There was no brown-tail moth scouting project carried on in this State during the 1939-40 season. 318 Connecticut Experiment Station Bulletin 445 < Eh w to 01 c u re < * "3 -o 01 t~ 0 < 01 3 0 o W *; o> 3 1 O o EQ to •tt -c 0) c re ft OQ ft 0/ 0) T3 re re 01 > c. J3 re 3 3 J Pi T3 ■c J re 01 Oi H^ § tl 13 0) 01 0) J2 c c >> £ 3 c4 c a o to ■a to 01 01 +J M 0 to W W re s 0 01 u o re n XI c c 0) c 3 o c i—i CO C * o H OOOOOOOOO IO OO IO — — I CM ou-iooooor^o ~ CM OOOOOOOOO o r^oooooooo v£> OOOOOOOOO o OO o o O O OOOOOOOOO (S — H (^ — < CM Ol CT\ CM -H 00 en ■*■ cm - OS c c h 12 6 r — i o t>T cnT c4 ^r OCtNOKO on o on ^r on in oo in rj tN. tN. in (n. in oo oo tt< on ro O oo — rN. >o — OOOO ON O CO OO nO O CN OO — " in ro cn O O O oo in On O CN OOn O — oo O OO — — — O ootM-no I ^ J3 ot " -o '- a -£" 2c o -• ro- 10 ^12 1? ^ °^ >. u 3 ^ 3 c >~"0 z 320 Connecticut Experiment Station Bulletin 445 u 0) V C s ni G - Pi -d T3 1-1 01 01 3 u T3 Ol 0) 01 £i '3 o >> i ni 3 o o Pi 03 n 01 01 -p w. o to m W ni £ o 01 o i W T) fi S 01 C d «H o fi l-l R is o H OOinOOOOOoOOOOOOONOOOOOOcO inNO—«NCCNin<-^cN — -oiAao\*owooo«on i—i (^inOv^inOoO^t^HOCNtnKyDoO N. — t)-i ■T1 r^ no — oouimiN — -ir^ooJf — vo no co o -^H „ _ , rT) -r-i ON " CN ~ -i ON OOO- C(NOO^« OOOOOCN — O O^f ^i"1 ~ o r-» CN C^ OOnoO -f OO (Ni OOoO ON in — _ ^,-N NU)q NiriN co in co — O -*< in vd co on O ^ in — (^ — i " iCOinC^O^OMiOOONVOlnKOOvO^rfiO O cn r^ -*i o in — i cnvoooo r^ cxd 1*1 CO i— i OnnocO ^i ^f CN i— i—i f^~i—i mocNCooooooooor^omooooi-HOo co in co Tji vo co in o >o on in co oo in vo co i— no on >OO^C(NOCOi OOO-^— i — ^- — oot^oo f J3 ro qj ±£ '>£ c :U b >i O aJ.dJ.O.O 0 Did 3 9 «i.a U X a "■cqoqUUUOX^^S^ZZZoJww (h 03 (0 .~ O £££££ Report on the Gypsy Moth, 1 9 39-1 9 W 321 < * a § ft -S M — 3 ■gfi C O vo rsi cm oo oo ■*■ oo -"-MONK — — nOK^ CN ON rs" en O "1 N O oo ^O f — CM ro oo WN r^ NO ON O — ■*" O NO l-^ — ^O <^J ON NOWN -T1 000 O OO O in OJ oo U-N O NO — — o «n m vo no vo o rsi r" rO N ^ r^ r^i — < — < m'rJo" — vO(N(N oo — CM « t>!5t} i. ? y ~~ ON OJ < to „ Q o . C/J «^ "UCO>-' c ro -a " c c ,-- re re :zj << UQQUU >£, 322 Connecticut Experiment Station Bulletin 445 DUTCH ELM DISEASE M. P. Zappe During the past year this Station has continued its cooperation with the United States Bureau of Entomology and Plant Quarantine in the control of the Dutch elm disease. The Bureau of Entomology does the actual control work and the Station carries on research and assists in obtaining permission of the land owners when control measures are necessary on their property. This Station also takes samples from certain new diseased trees found by the federal scouts, particularly in towns not previously known to be infected. Cul- tures are made from these samples and, if found to be positive, the trees are cut and burned. Dr. F. A. McCormick of the Department of Plant Pathology and Botany made a total of 123 cultures in 1940. With the increasing scarcity of W.P.A. labor, the sanitation work has been somewhat curtailed. The ice storm in late winter of 1940 left many elm branches broken and hanging in the trees. All these were potential beetle breeding material and had to be re- moved. This added to the amount of work which had to be done to prevent an increase of bark beetles. Three hundred seventy-eight diseased trees were found and destroyed during 1940. This makes a total of 1,686 trees which have been found infected with Dutch elm disease and removed since the work first started in Connecticut in 1933. Forty-one of those discovered in 1940 were in 17 towns in which the disease was de- tected for the first time. They are as follows: Town Bethany Bethel Bethlehem Brookfield Harwinton Middlebury No. of diseased trees 2 2 10 1 1 2 Town Morris Naugatuck New Haven New Milford Orange No. of diseased trees 1 1 1 1 1 Town Preston Torrington Wallingford Waterbury Watertown Woodbridge No. of diseased trees 1 1 3 4 2 7 None of the new towns were far from the area generally in- fected with the exception of Preston, where one diseased tree was discovered. This town is 25 miles from the Old Lyme area where no diseased trees have been found since 1937. The Preston tree was about 50 miles from the nearest diseased tree found in 1940 in Guilford. The federal and state quarantines will probably be ex- tended to include the towns where diseased trees were found this year. MOSQUITO CONTROL IN CONNECTICUT, 19401 R. C. Botsford, Field Agent State Board of Mosquito Control No serious mosquito nuisances were observed or reported in the state-maintained areas during 1940. Mosquito Control in Connecticut, 1940 323 Routine duties of maintenance comprised the principal activity of the control crews this season. Your agent regularly inspected key points of control and potential breeding areas, and kept in constant touch with the crew foremen by telephone and personal contact in the field. Thus, jammed tide gates, damage to outlets, and complaints of mosquito nuisance, all of a minor nature, were promptly serviced. No set plan of maintenance of the 11,000 acres of salt marsh could be followed because the crews were moved from place to place as the emergency required. Your agent attended the annual convention of the New Jersey Mosquito Extermination Association at Atlantic City, New Jersey, March 20-22, 1940, and read a short paper on mosquito control work in Connecticut. He also conducted a Connecticut field trip June 27, 1940, under the auspices of the Eastern Association of Mosquito Control Workers, showing some important W.P.A. projects associated with mosquito control. Mosquito breeding developed in Fairfield in the Pine Greek Marsh, and oiling was necessary, the Town of Fairfield furnishing the oil. Breeding also developed near the Branford River and at East River, both of which areas were oiled. Other small breeding places were eliminated by spur ditching. Tide gate construction would improve areas in Branford, at Sybil Creek; in Fairfield, at Pine Creek; and in Clinton, at Indian River. Federal aid mosquito control projects under the W.P.A. were reduced in number this year. Inability to secure the necessary spon- sors' share of the cost and the reduction in numbers of relief labor were the principal reasons for this. On December 10, 1940, the Board was notified that the statewide projects sponsored by the Board would no longer be operated by the Ditching, Draining and Pest Control Project, also that no agency of the W.P.A. could ren- der further engineering services, nor aid in obtaining releases. The individual projects are to be administered by the local area offices of the W.P.A. Three sub-projects of the statewide project remain in operation under local W.P.A. administration: Canoe Harbor, Madison; Great Harbor Dike, Guilford; and Pitkin Street, East Hart- ford. The Pitkin Street job is 80 percent completed and the remain- ing engineering work may be completed by the town engineers. The Canoe Harbor and Great Harbor jobs are more complex and will require periodical engineering services. The year 1941 will prob- ably see the end of W.P.A. assistance in mosquito control work. The following is a list of projects completed in 1940 or now in operation by W.P.A. transferred from the Pest Control Project to local area offices. All are town-sponsored excepting as noted. Ansonia: Beaver Brook, slope paving and retaining walls. Colony Street; completed. The mosquito control work in Connecticut is now administered by a State Board of Mosquito Control of which the Director of this Station is chairman. Since the Board has no means of publication, the report of its Agent is given here. 324 Connecticut Experiment Station Bulletin 445 East Hartford: Panzy's Pond and Pitkin Street, correcting drain- age; 80 percent completed. Board sponsored by request. Fairfield: Pine Creek Bridge; completed. Rooster River, storm water improvements. Groton: Benham Road and Warren Street, draining swamp. Guilford: Great Harbor Dike, rebuilding dike damaged by hurri- cane. Sponsored by Board. Madison: Canoe Harbor, marsh outlet and draining swamp. Spon- sored by Board. New Britain: Piper Brook, corrective work. Bass Brook; completed. New Haven: Lawncrest Brook, drainage completed. West River and Wilmot Brook, temporarily sus- pended. Little River, tide gate construction. East Shore Meadows, improving outlet; 80 percent completed. North Haven: Blakeslee Road, swamp drainage; completed. Norwalk: Lockwood Lane, swamp drainage; 75 percent completed. Plymouth: Pequabuck River, corrective work; 60 percent com- pleted. Stratford: Sniffen's Meadow, new outlet; 95 percent completed. Bruce Brook, bridge and corrective work. West Haven: Cove River, tide gate and sea wall. Westport: Town Dump Swamp, drainage; completed. Pussy Willow Swamp, ditching and corrective work. RODENT CONTROL Howard A. Merrill, Assistant District Agent Fish and Wildlife Service, U. S. Department of the Interior During the year research has been continued on the ecology and the control of pine! mice {Pity my s pinetorum); the fluctua- tion or cyclic tendency of the population of meadow mice (Microtus pennsylvanicus) ; and the use of repellents as a protection for trees and shrubs against rabbits. Although a great deal is yet to be accomplished on all of these projects, progress is being made. Obser- vations will be required for a period of several seasons before defi- nite conclusions can be drawn. Pine Mice Research in the control of pine mice has entered its "stubborn" phase. Proper baits and poisons for control have been determined. The proper placing of these baits in the field under varying cultural practices has been fairly well established. However, the seasonal activity and behavior of pine mice, their rate of breeding and rein- Rodent Control 325 festation, and the general population cycle or fluctuation, do not form as simple and well known pattern as in the case of meadow mice. Upon these factors depend the time of year and number of applications of the control method. Such information is gained prin- cipally through long term investigations on the ecology of pine mice. Research studies have been in progress in three widely separated sectors of the eastern fruit belt: in New York, Pennsylvania, and Delaware by D. A. Spencer; in the Shenandoah Valley, Virginia, by H. J. Spencer; and in Connecticut by H. A. Merrill. In Connecticut during the early part of the winter (1939-1940) the pine mouse population was reasonably high, as determined by trapping in several orchards and by observations in others. During the latter part of February and March the population was reduced greatly. The exact cause of this reduction is not known; climatic conditions, however, were severe. During the first two weeks in February an examination of a 10-acre block of mature apple trees was made at South Windsor, Connecticut. Numerous signs of pine mice were observed fairly evenly distributed over the entire block. One row selected at ran- dom, approximately in the center of the orchard, was trapped on February 13 and 14, most of the traps being set in underground burrows just below the sod. Pine mice were caught under 10 of the 17 trees in the row. A severe snow storm made it impossible to do further trapping at that time. An attempt was made to continue the trapping during March. However, a heavy layer of ice under the snow made this attempt unsuccessful. A few days of warm weather had melted some of the snow, allowing the water to run down into the burrows where it froze into solid cylinders. Trapping was resumed again in April, as by this time the ground had thawed and conditions were more favorable for making under- ground sets. However, no mice were caught after trapping the entire block. No poisons had been used on the area. Similar conditions were found in other orchards throughout the State, and this low population in the spring made many of our projects difficult. The area established to study the rate of drift or reinfestation was made valueless because of the natural reduction in population in the sur- rounding area. The effectiveness of concentration stations, in the form of tar paper squares and burlap squares, has been checked under various conditions. Under sandy soil conditions with light vegetative cover, pine mice were found to mound up the sand under the concentration station, making poisoning practically impossible. Under loam condi- tions with heavy vegetative cover, the concentration station did not give satisfactory results even after exposure for several months. In conjunction with the collection of pine mouse stomachs, which are to be used in determining the general food habits and the months when the mice are feeding on apple tree roots, certain breed- ing data have been obtained, as indicated in Table 6. 326 Connecticut Experiment Station Bulletin 445 Table 6. Pine Mouse Breeding Month Total Males Total Females Juveniles' Females Average Examined Examined Examined Pregnant Litter (adult) (adult) April 21 23 6 6 2.00 May 21 20 12 7 2.14 June 9 12 3 4 2.50 July 11 12 1 4 1.75 August 11 10 6 5 2.20 Sept. 14 10 7 6 2.66 Oct. 14 11 5 2 2.00 Nov. 11 14 1 0 Dec. 16 13 3 0 Tine mice weighing 20 grams or less are classified as juveniles. Meadow Mice The meadow mouse population was checked twice during the year, once during May and again in September. This census in- cludes the work of 1 1 investigators reporting from 13 widely sepa- rated districts in the northeastern fruit belt. Field studies were made on approximately 150 different Microtus habitats and inten- sive trapping on 18 selected acre quadrats. To standardize this Microtus population survey so that the readings of each investigator would be comparable, the following plan was followed: (1) In orchard areas, 50 tree bases in a block were examined for Microtus trails. (2) In meadow areas, six quadrats measuring 10 feet on the side and spaced at 20-foot in- tervals were read for the linear length of Microtus trails contained thereon. All surveys were required to be of areas representative of at least five acres of similar cover. (3) Supporting these trail sign surveys, each investigator trapped free an acre that he judged above the average in Microtus infestation in his district. Extreme Variation in Microtus Numbers. The peak in the Microtus cycle terminated in late spring of 1939, through causes unknown. This was followed by a summer of severe drought in most of the Northeast that prevented any appreciable recovery during that breeding season. The winter of 1939-1940 was severe, the late spring replete with ice storms, and the population density was further depressed. With three successive blows it is no wonder that Microtus practically disappeared from many habitats. Thus, we may consider that the breeding foci in the spring of 1940 were not only low in numbers but scattered according to protection af- forded by very localized habitat conditions. April, May and June of 1940 had above normal temperature and rainfall which resulted in excellent cover and food. Conditions then sharply reversed to below normal rainfall during July and August, checking plant growth. Several investigators made note of the fact that where mulching was practiced in an orchard the Microtus populations were no- ticeably higher. Such cultural practice aids in moisture conservation Rodent Control 327 and improvement of plant growth. It is reasonable to suppose that the mice on such mulched areas benefited during the July-August dry spell. So, with (1) an uneven breeding-stock beginning, (2) followed by variable habitat conditions, and (3) with no outside population pressure resulting in drift, it was not surprising to find two favorable habitats in September only a few miles apart, one with 50 Microtus per acre, the other with three. The high population records in May, 1940, were in northern New York, and it is in this same region that the highest September population of 78 Microtus per acre was recorded. The Microtus population in September, 1940, was generally low but exhibited extreme variations. The general mouse population had not increased over the figures for September, 1939; however, the dis- tribution was more variable. Infestations of 10 per acre were usual; but in every sector very localized infestations of 75 to 150 per acre were encountered. The 1940 breeding season was not too favorable for increase despite the improved cover and food conditions over the preceding year. From the investigations made, only 32 percent of the best Microtus habitats were infested. In other words, population pressures have not reached a point where Microtus occupy more than half of the best habitats, thus leaving marginal areas almost devoid of mice. Studies from other years of rapidly expanding population indi- cate that the number of immature mice is triple that of breeding adults. The records for September, 1940, show that the number of breeding adults exceeded that of immature mice by a small margin. (Microtus below 28 grams in weight are considered immature, as it is exceedingly uncommon to find pregnancy below that level.) At the time of the September, 1940, census, 66.2 percent of the adult females were found to be pregnant, the average litter size be- ing 5.17. On the basis of no deaths, the population reported would have doubled by October 1. Rabbit Repellent Study To determine the efficiency of rabbit repellents and the effect of these materials on the cellular structure of the trees, numerous tests have been started. The repellents being used are developed by the Fish and Wildlife Research Laboratory. Tests were first made under cage conditions at the University experimental rabbit pens at Storrs, and later field applications were made on trees in the University experimental orchard, the Hale Orchard in Oxford, Connecticut, and Gardner's Nurseries in Rocky Hill, Connecticut. During the coming year more extensive tests will be made, using spray and brush applications on a variety of trees and shrubs frequently damaged by rabbits. During the spring of 1939, 40 apple trees (three-fourths-inch to one-inch stock) of various varieties were planted in the University 328 Connecticut Experiment Station Bulletin 445 experimental rabbit pens. Four pens were available and 10 trees were planted in each pen. These pens are 15 feet by 30 feet and have a heavy vegetative cover as well as considerable sprout growth. Piles of pine boughs have been placed in each pen to provide pro- tection during the winter months. Repellents were applied as a paint to 22 trees and 18 trees were left untreated for checks. Fre- quent inspections are being made regarding the effectiveness of re- pellents as well as their effect upon the cellular structure of the plants. One field application was made on apple and peach trees at the University experimental orchard during the spring when the newly planted trees were in a growing stage. Fall applications were made on apple trees in the Hale Orchard and Gardners Nurseries. Two hundred fifteen trees were treated in the Hale Orchard and 50 trees were treated in Gardner's Nurseries. In both cases severe rabbit damage was being done at the time of application. REPORT ON PARASITE WORK FOR 1940 Philip Garman, J. C. Schread, W. T. Brigham and G. R. Smith During 1940, as in previous years, parasite work was carried on in cooperation with the Connecticut Pomological Society and the U. S. Bureau of Entomology and Plant Quarantine. Oriental Fruit Moth Parasites We received 73 orders for parasites from peach growers and placed a total of 119 colonies representing 66.185 individuals, all Macrocentrus ancylivorus. Extensive egg, twig and band collections were made in order to determine the degree of parasitism that occurred throughout the State. In this work, 14,000 twigs were collected, bands were placed in 22 orchards, and egg collections were made in 32. Egg parasitism was low in June, increased to a high point during July, and receded to moderate figures in August. There was great variation from orchard to orchard. Larval parasit- ism was likewise low in June and highest in July collections, and showed similar variation in degree from orchard to orchard. Infesta- tion counts continue to show correlation between size of population combined with degree of parasitism and fruit infestation. Figures for four orchards where complete data were obtained are shown in Table 7. One of these orchards (Hanford) showed a very high in- festation last year and observations indicate that it is being brought under control by parasites. In this 300-tree orchard, a total of 1,800 parasites {Macrocentrus) were placed on the following dates dur- ing 1940: June 14, July 8, July 10, and July 25. Band collections made in August indicate that many parasites were present in numerous orchards and that secondary parasites were scarce. Table 8 gives an idea of the amount of parasitism as determined by band collections. The method consists of placing corrugated paper bands on the trunks about one foot from the ground Report on Parasite Work for 19 UO 329 and removing them before the moths emerge, usually in about one month. It is believed that orchards showing low parasitism in band collections will need particular attention in 1941. Table 7. Oriental Fruit Moth Parasite Work — 1940 Rating after Percentage Orchard Population deduc ting losses infested fruit estimate1 from parasites2 at harvest Bussa 15.0 1.89 2.1 Andrews 29.5 8.6 15.2 Hanford 45.0 5.0 15.2 Musante 44.7 18.7 73.53 Estimate based on number of fruit moth eggs collected per hour on several dates during July and adjusted to conform with collection of larvae in tips during the same period — also on an hourly basis. 2Obtained by deducting from column headed "Population estimate" the per- centage egg, larval and pupal parasitism as determined by laboratory breeding from field collected tips. 3Short crop and later variety than Elberta possibly account for the high infes- tation in part. Table 8. Parasitism Determined by Band Collections During August — 1940 Fruit Moth Orchai'd and Location % parasitized Burns — Oronoque 28.9 Farmill — Shelton .». 84.2 Hanford — Fairfield 71.8 Conyers — Greenwich 35.9 Hurlbut — Wilton 74.9 Warncke — Cannondale 62.1 Josephy — Bristol 48.2 Andrews — Glastonbury 75.6 Bussa — Glastonbury 80.8 Rogers — Southington 36.7 Root ■ — Farmington 27.5 Pero — Manchester 69.5 Peters — Hamden 92.4 Piatt — Milford 67.5 Musante — Seymour 3.7 Recoveries. A great many parasites were found during the course of the 1940 work. Inareolata (Diodes) molestae was recov- ered in eight orchards, and Bassus diversus in only one (Table 9). There is some indication that Inareolata (Dioctes) molestae may survive longer than formerly suspected, but our data are too meager to draw conclusions at the present time. Our best results with this parasite appear to be in the Pytka and Spicer orchards, which are adjacent. Here the parasitism has continued at about the same level during 1939 and 1940. Recoveries of Bossies diversus in 1940 were disappointing compared with those in 1939. 330 Connecticut Experiment Station Bulletin 445 Breeding. During 1940 Mr. A. DeCaprio collected a large quantity of strawberry leaves infested with parasitized leaf rollers in New Jersey, and as a result we doubled the usual production of Macrocentrus ancylivorus. Considerable credit is due Mr. DeCaprio for the way the work was handled. Miss Mary A. Root assisted in laboratory work during both 1939 and 1940. Her help has released men from the laboratory, increasing the amount of field work pos- sible. Table 9. Foreign Parasite Recoveries 1940. Orchard and location Date of last liberation Harwig — Mill Plain 1938 Josephy — Bethel 1939 Shepard — Danbury 1938 Bassus diversus Orkil — W. Simsbury 1939 Number of specimens Inareolata (Diodes) molestae Musante — Seymour 1939 Kneuer — Guilford 1933 Farmill — Shelton none Pytka — Deep River 1938 Spicer — Deep River 1938 males females male female male female males female males females male females male males 1 female Japanese Beetle Parasites and Disease This work was carried out entirely in cooperation with the U. S. Bureau of Entomology and Plant Quarantine, on whom we have been dependent for supplies of parasites and disease. During the season, locations were scouted and dug to determine grub infesta- tions. Twenty-five colonies of Tiphia vernalis were liberated. Localities where previous liberations (with a few exceptions) had been made were scouted. Tiphia vernalis was recovered in six lo- calities and parasites, presumably this species, were observed in three others. It is apparent that at least one colony has become well established in Bridgeport and is spreading rapidly. Investigation of the larval disease recommended for control by the Federal Bureau was started. Inoculation work consisted of inject- ing the disease into 15,000 to 20,000 grubs which were then sent to Moorestown for processing and mixing with talc carrier. A total of 15 one-acre plots have now been laid out in different parts of the State and systematic diggings are being made to determine the pro- gress of the disease. In addition to this work, laboratory inoculations of the Asiatic beetle were made successfully, and several field plots laid out near New Haven. Outline Map 331 332 Connecticut Experiment Station Bulletin 445 lliliiiiliillyillLiiJlililiiililiiiilil^s ^^M Study of Stickers for Spray Materials 333 Nematode Parasites Through the courtesy of the New Jersey Department of Agri- culture we secured a quantity of nematodes for experimental lawn treatments against Asiatic and Japanese beetles. As with the disease work, it is too early to make any statement regarding effectiveness of the treatment. Altogether four plots were laid out. The outline maps (Figures 1 and 2) show the location of nema- tode and disease plots as well as Tiphia vernalis liberations. CONTINUED STUDY OF STICKERS FOR SPRAY MATERIALS Philip Garman and C. E. Shepard During the 1940 season experiments were continued with stick- ers for lime-lead arsenate and lead arsenate alone. As in pre- vious years oils seem to increase the amounts adhering after one month in the case of lime-lead arsenate combinations, but aluminum sulfate and aluminum acetate have closely approximated the results obtained with oils. The percentages remaining are shown in Table 10, which gives comparative figures for the last three years. The percentage gain in many cases is not large and would probably not be reflected in readily observable increases in insect control. How- ever, in a complete schedule of lime-lead arsenate sprays where three or more applications are made, this difference might easily be- come important. In another series, "dynamite' sprays have been used with the idea of reducing the total number of sprays applied throughout the season. In addition, for the first time this year, we used a modified formula containing aluminum acetate1 and a small amount of benzoic acid. It has been found possible to emulsify white oils with this combination in place of soaps or other agents. Results of insect control and sticking properties have been gratifying, the new mixture comparing favorably with "dynamite". It was noted during the sea- son that the modified formula did not show the leaf drop that was evident on the "dynamite" treated trees, and as a result the fruit appeared to be larger at harvest. All trees were thinned alike dur- ing the season to avoid discrepancies occurring from varying amounts of fruit. The size of apples is reflected in the number per 100 pounds (last column of Table 11). In the "dynamite" series only three sprays were applied, whereas the normal summer schedule calls for six and some growers apply 2The Department of Analytical Chemistry reports this to be aluminum aceto- borate. 334 Connecticut Experiment Station Bulletin 445 more than that. The situation for the experiment is an extremely difficult one from the standpoint of both curculio and apple maggot control. Table 1 1 gives the figures obtained from examination of the fruit at harvest, and indicates that the modified formula is fully as good as the straight "dynamite" sticker. The type of cover is different, however, the poison being deposited in spots instead of being continuous (Figure 3). Various growers examined the trees during August and expressed satisfaction with the foliage and fruit. Figure 3. Spray residue remaining on apple foliage sprayed with modified dynamite on June 12. Photograph made September 16. It is evident, however, that much more work needs to be done with this type of material before it can be considered of commercial value. There is, for example, the fungicide problem, which, although partly solved with the mixture, is not solved for situations where scab is serious or for varieties that scab badly, such as Mcintosh. This and other problems need attention before this promising mixture can be released from the experimental field. Study of Stickers for Spray Materials 335 Table 10. Comparison of Stickers for Lime-Lead Arsenate. % AS2O3 ' % AS2O3 Year Sticker remaining Year remaining % gain after 1 month after 1 month for sticker 1940 Fish oil 25.7 1940 Check 22.8 2.9 1940 45.8 1940 45.7 .1 1939 22.0 1939 14.0 8.0 1939 51.0 1939 35.0 16.0 1938 25.4 1938 13.6 11.8 1938 47.4 1938 25.4 22.0 1939 Perilla oil 28.0 1939 14.0 14.0 1939 65.0 1939 35.0 30.0 1939 Soybean oil 21.0 1939 14.0 7.0 1939 60.0 1939 35.0 25.0 1939 Aluminum sulfate 25.0 1939 14.0 11.0 1939 61.0 1939 35.0 26.0 1940 Aluminum acetate 48.0 1940 45.7 2.3 1940 28.1 1940 22.8 5.3 ^Analyses made immediately following sprays and again at the end of one month. Table 11. Summary of Results with Dynamite Sprays — 1940. Variety, Baldwin. Total Tree fruits % clean % curculio % codling moth % maggot Apples per 100 lbs. Treatment per tree M6 3371 L6 3583 70.1 72.0 22.2 23.5 2.4 4.5 13.9 6.0 299 369 Western "dynamite" 3 sprays Averages 71.0 22.8 3.4 9.4 334 U7 5223 L7 3950 M8 2544 L8 4636 83.2 70.2 77.5 74.6 11.5 18.5 12.9 20.3 3.5 4.0 6.1 3.9 8.0 4.0 4.0 7.8 281 275 296 297 Modified "dynamite" 3 sprays Averages 76.3 15.8 4.3 5.7 287 L9 " 1053 8.4 72.7 29.6 70.0 Check — no spray Treatment — Modified "dynamite" as Aluminum acetate Benzoic acid White mineral oil Lead arsenate Water follows: 1 lb. .25 lb. 1 qt. 1.5 lbs. 50 gals (doubled at Calyx spray) Western "dynamite": White oil with 5% oleic acid Monoethanolamine .7% solution Lead arsenate Water Vi gal. 3 lbs. 100 gals. (6 lbs. at Calyx) Sprays applied: May 17 (Pink), May 29 (Calyx), June 12 (1st Cover) 336 Connecticut Experiment Station Bulletin 445 Table 12. Adhesion of Arsenic in Dynamite Spray Tests — 1940. Figures Are Micrograms As20-, per 100 One Sq. Cm. Discs. Dates of Examination % AS2O31 Tree 6/16 7/16 8/16 9/16 remaining 9/16 Treatment M6 2858 2571 1431 1612 56.4 Western "dynamite" M7 2331 2571 2000 1725 74.0 Modified "dynamite" N6 2369 2047 1875 1463 61.76 Western "dynamite" N7 2124 2161 1741 1500 70.6 Modified "dynamite" 'Percentage of the amount found by analysis to be present on the foliage June 16. NOTES: Spray schedule given in Table 11. Rainfall June 16 -Sept. 16, 8.66 inches. EXPERIMENTAL CONTROL OF THE ORIENTAL FRUIT MOTH Philip Garman Through cooperation with Mr. Walker of the General Chemi- cal Company of New York, a quantity of an insecticide known as "Genicide" was obtained for experiment. This material was ana- lyzed by Doctor Fisher of the Department of Analytical Chemistry and found to contain Xanthone. Cooperative experiments were con- ducted, using two commercial orchards and the Experiment Station plot at Mount Carmel. The plots at Mount Carmel and Milford were set up so that counts could be made of fruit from adjacent sprayed and unsprayed trees in different parts of the orchard. These data are set forth in Tables 13 to 15. From them, it is apparent that there was considerable gain in fruit free of new injury. While this was not great enough to be practical in the case of the Hale Orchards, there is considerable consistency throughout the experi- ment. In the case of Piatt's at Milford, the fruit approached a rea- sonably satisfactory point. The difference between treated and checks appeared to be very significant by statistical analysis. The orchards at Mount Carmel and Milford were sprayed with our Experiment Station outfit. Applications at Seymour were made by Mr. Scott of the Hale Orchards. In order to check more fully on the field results, laboratory tests were conducted using small green apples and infesting them arti- ficially by placing a number of fruit moth eggs on each. Analysis of variance indicates that the difference among treatments is significant, and that Genicide is better than either checks or lead arsenate (Table 16). Experimental Control of the Oriental Fruit Moth Table 13. Oriental Fruit Moth Control — 1940. Platt's Orchard, Milford. Picked Fruit — Elberta. Ou i Sprayed Unsprayed Difference Tree Percent "new" Tree Percent "new" Tree plot injury plot injury plot 1 5.8 1 33.0 1 27.2 2 8.4 2 24.4 2 16.0 3 8.1 3 24.1 3 16.0 4 13.3 4 44.3 4 31.0 5 10.5 5 25.6 5 15.1 6 5.2 6 24.3 6 19.1 7 8.8 7 23.4 7 14.6 8 16.5 8 36.1 8 19.6 9 3.0 9 29.5 9 26.5 10 12.5 10 23.4 10 10.9 Averag* i 9.2% 28.8% 19.6% Control approaching satisfactory from a commercial standpoint. -Four sprays applied as follows: August 5, August 13, August 23, and Sep- tember 10. Genicide diluted 2 lbs. to 100 gals, water. Table 14. Oriental Fruit Moth Control — 1940. Experiment Station Farm, Mount Carmel. Picked Fruit — Elberta. Unsprayed Sprayed Difference Tree Percent "new" Tree Percent "new" Tree plot injury plot injury plot Percent 1 2.3 1 .9 1 1.4 2 7.0 2 .0 2 7.0 j 5.3 3 .8 3 4.5 t 2.2 4 1.8 4 .4 5 4.5 5 1.0 5 3.5 6 3.1 6 3.4 6 -.3 7 3.7 7 1.7 7 2.0 3 1.8 8 1.1 8 .7 9 2.1 9 1.1 9 1.0 10 4.1 10 1.1 10 3.0 11 5.1 11 2.4 11 2.7 12 .9 12 .6 12 J 13 7.8 13 3.6 13 4.2 Averages 3.8% 1.5% 2.3% Sprays same as in preceding table. 338 Connecticut Experiment Station Bulletin 445 Table 15. Oriental Fruit Moth Control — 1940. Hale Orchards, Seymour. Picked Fruit. Percent Percent Tree "new" injury- Tree "new" injury Tree Difference Sprayed Checks % 1 39.9 1 52.0 1 12.1 2 29.7 2 36.6 2 6.9 3 33.9 3 58.1 3 24.2 4 15.3 4 46.6 4 31.3 5 14.1 5 67.4 5 44.3 6 32.7 6 68.4 6 36.7 7 30.5 7 53.1 7 22.6 Averages 28.0% 54.6% 25.4% Average "new" injury from all fruit cut from Sprayed plots 31.1% and 30.2% Check areas 48.3% and 70.8% Differences 17.2% and 40.6% Notes: Control still considered unsatisfactory here because of the high infestation in sprayed plots. "New" injury does not include conspicuous second generation work which would have been done before spray operations began. Three sprays applied approximately August 5, 15 and 25. Dilution same as in two preceding tables. Table 16. Control of the Oriental Fruit Moth. Laboratory, 1940. Lead arsenate Genicide (Xanthone) Check — no 3 lbs. to 100 gals. 2 lbs. to 100 gals. treatment Eggs Larvae Eggs Larvae Eggs Larvae used matured % used matured % used matured % 30 5 40 4 33 20 30 14 30 2 36 19 29 23 36 2 36 12 19 7 35 0 28 28 32 16 37 3 44 17 25 17 38 1 — 36 7 37 1 177 96 54.2 37 24 39 10 40 17 33 2 38 20 39 2 316 150 47.4 368 25 6.8 General summary of the experiment % matured Check — no treatment 54.2 Lead arsenate 47.4 Genicide (Xanthone) 6.8 Notes : Green apples about 1 inch in diameter were punctured with 30 holes each, the bottoms tanglefooted and the calyces paraffined. Thirty to forty Oriental Experimental Control of the Apple Maggot 339 fruit moth eggs were then placed on each apple and allowed to hatch. The figures in the "eggs used" column represent only those eggs that hatched. After the larvae had entered, the apples were each placed in an individual jar and kept in an incu- bator until the larvae left the fruit and spun their cocoons. Formulae: Lead arsenate 1.5 grams in 416 ml. water. Genicide 1 gm., sodium oleate .5 gm., and zinc sulfate (monohydrate) .125 gm. in 416 ml. water. Table 17. Oriental Fruit Moth Control — 1940. Laboratory Experiments. Number eggs Number Percent Treatment hatched entered entered Check — no treatment 295 132 44.7 400 191 47.7 392 157 40.0 Totals and averages 1087 480 . 44.1 Genicide 228 14 6.1 282 74 26.2 230 68 29.5 1043 13 1.2 Totals and averages 1783 169 9.4 Lead arsenate 243 78 32.0 201 73 36.3 Totals and averages 444 151 34.0 Procedure — 60 holes made in small apples about 1 inch in diameter; apples then tanglefooted below and Oriental fruit moth eggs placed on top. "Entries" determined by digging into the fruit several days after hatching. EXPERIMENTAL CONTROL OF THE APPLE MAGGOT Philip Garman Continued study of the apple maggot in 1940 gave interesting results. Laboratory Work Our laboratory work consisted largely of attempts to determine whether rotenone dusts could be improved, especially in their resist- ance to action by light. A commercial sun lamp was obtained for this purpose. The source of light in this apparatus is an S4 Mazda bulb, furnishing ultra violet rays said to be considerably stronger than sunlight. Material tested was dusted on 3.25 x 4.25-inch glass slides and placed 12 inches from the bottom of the bulb. After the period of exposure the slides with exposed dust were placed in small cages where they served as windows, with the insecticide turned inwards. Counts of dead and paralyzed flies were made after 24 and 48 hours. In some cases the slides were replaced by clean ones after 48 hours and the reading taken two days later. Experiments given in Table 18 were made with stabilized derris compared with unstabilized derris from the same source, the dusts being mixed both with and without white lubricating oil. The amount 340 Connecticut Experiment Station Bulletin 445 of material on each slide was weighed carefully. The figures obtained do not show any striking differences in favor of the stabilized derris and the data were analyzed statistically by Dr. C. I. Bliss without discovering significant differences. A number of materials were then tried for reducing the effect of light, some of which appeared promising. Dusts with 10 percent lamp black were not destroyed as rapidly, a fact well known since the work of Campbell. However, dusts made up with iron hydroxide appeared to be better than those with lamp black (Table 19), and this led to an investigation of red clays for the purpose. One of these, known as Hall clay from the United Clay Mines of Trenton, offers some promise. Formulae were made up with this red clay instead of pyrophyllite and exposed to rays of the sun lamp, Tables 20 - 22. In these tests there appears to be a consistent advantage for the red clay which increases with length of exposure to the sun lamp within the experimental limits. Later, exposed and unexposed slides were submitted for chemical analyses to the Department of Chemistry. Doctor Fisher's report is given in Table 23. The re- sults confirm our biological tests showing definitely that rotenone is less rapidly destroyed when mixed with the red clay. A number of new materials have been tested, some of which show toxicity for the apple maggot fly. Perhaps the most promising of these are pyrethrum-oil dust, two soluble antimony compounds, and Phthalonitrile. Acetone semicarbazone also has some toxicity. Pyrethrum-oil is not quite so efficient as rotenone dusts though it has some repellent or deterrent action, reducing the number of egg punctures in the fruit. The materials have not been sufficiently studied to comment further. Field Studies Field experiments were conducted in two different orchards using rotenone dusts prepared from derris by Apothecaries Hall Company of Waterbury. These dusts, prepared to contain .5 per- cent rotenone, were analyzed by Doctor Fisher and reported to con- tain one and a fraction percent of rotenone, a figure probably high because of the presence of deguelin which is not separated in the analyses. Counts continued to show control of the apple maggot in the Burton orchard at Mount Carmel, Tables 24 and 26, and indi- cate fairly consistent results for the last three years. We also em- ployed here some rotenone dust with lamp black but were forced to discontinue it after two applications, owing to unfavorable appear- ance of the fruit. In the Westwoods Orchard, Cortlands, very heavily infested in 1939, were dusted six times. The infestation on dusted trees was considerably reduced in spite of the fact that the orchard as a whole was heavily infested and nearly all untreated fruits dropped from the trees by September (Table 25). It is evident that .5 percent rotenone-oil dusts may have a place for late season work, especially since flies were seen this year in Experimental Control of the Apple Maggot 341 various orchards until late in September. The rapidity of destruc- tion of the insect continued to be apparent, although loss of effec- tiveness occurred within four or five days, after which period flies could again be seen in the trees. It is with this in mind that experi- ments are being continued. Table 18. Experiment to Determine Value of a "Stabilized" Derris. Mortality of Apple Maggot Flies in Laboratory Cages — 1940. Material Exposed to S, Sun Lamp at Uniform Distance from Insecticide (12 inches). Date Expt. number Material Exposure to light in hours Mortality 24 hours Mortality 48 hours Number flies in cage Weight of material on slide. grams Jan. 16- 18 D 1 2 3 4 0 0 0 0 17 17 22 19 17 17 22 19 17 17 22 19 .0052 .0041 .0059 .0055 Jan. 17- 19 F 1 2 3 4 2 2 2 2 11 8 14 10 13 11 15 13 13 18 19 16 .0049 .0046 .0048 .0054 Jan. 18-20 G 1 2 3 4 2 2 2 2 12 9 14 17 19 12 14 19 19 20 14 19 .0054 .0051 .0030 .0050 Jan. 18-20 H 1 2 3 4 2 2 2 2 13 6 9 6 18 13 14 12 20 20 22 19 .0057 .0053 .0049 .0053 Jan. 18-20 I 1 2 3 4 2 2 2 2 6 6 6 5 10 10 11 9 17 19 18 19 .0041 .0058 .0047 .0047 Jan. 16-18 E 1 2 3 4 4 4 4 4 2 0 1 4 7 2 4 5 18 19 19 19 .0045 .0043 .0047 .0041 Jan. 15- 17 C 1 2 3 4 8 8 8 8 0 0 0 0 3 0 1 1 12 15 19 21 .0041 .0045 .0033 .0044 Jan. 13-15 A 1 2 3 4 20 20 20 20 0 0 0 0 0 0 0 0 17 17 22 19 .0037 .0030 .0023 .0026 Notes : Insecticide dusted on slide with settling tower and exposed to action of S4 Mazda bulb 12 inches from the plate. Slides so treated were used to make a 342 Connecticut Experiment Station Bulletin 445 window in a small cage with the insecticide turned inwards. Data analyzed by statistical methods show no significant differences. Formula No. 1. Unstabilized derris, 10 gms.; pyrophyllite, 90 gms. No. 2. Stabilized derris, 10 gms.; pyrophyllite, 90 gms. No. 3. Unstabilized derris, 10 gms.; pyrophyllite, 86 gms.; 85 vis. white oil, 4 gms. No. 4. Stabilized derris, 10 gms.; pyrophyllite, 86 gms.; 85 vis. white oil, 4 gms. Table 19. Comparison of Three Dust Formulae for Killing Apple Maggot Flies. Light Exposure 20 Hours, S4 Sun Lamp. Mortality Mortality Gain for Dates Formula 48 hrs. % Formula 48 hrs. % No. 7 over No. 12 % Feb. 12-16, 1940 12 46 7 41 + 6 Feb. 10-14, 1940 12 30 7 78 + 38 Feb. 1-3. 1940 12 41 7 73 + 32 Feb. 1-3, 1940 12 44 7 100 + 56 Feb. 10-14, 1940 1 0 Feb. 12-16, 1940 1 0.7 Jan. 13-15, 1940 1 0 NOTES: Formula No. 7 contains (90%) Ferric hydroxide, .5% rotenone. No. 12 contains 10% lamp black, 80% pyrophyllite, .5% rote- none. No. 1 contains 90% pyrophyllite, .5% rotenone. Table 20. Comparison of Pyrophyllite (Formula 1) and Hall Clay (Formula 15) as Carriers for Rotenone. Summer 1940. Light1 exposure Mortality in 48 hours Formula 1 % Formula 15 % Gain for No. 15 % 4 hours 8 hours 16 hours 24 hours 96.1 92.2 61.5 62.8 92.5 96.9 20.1 10.7 3.6 5.3 41.4 52.1 *Sun lamp, S4 bulb, 12 inches from slide with insecticide. .5% rotenone in both formulae. Experimental Control of the Apple Maggot 343 Table 21. Comparison of Two Dust Formulae for Killing Apple Maggot Flies. Laboratory Tests, 1940 — .5% Rotenone in all Formulae. Formula No. l Formula No. 15 Gain for Number Mortality % Number Mortality % No. 15 Date of flies 48 hrs. kill of flies 48 hrs. kill % 8 hour exposure to sun lamp Aug. 12 21 16 76.1 19 16 84.2 + 8.1 Aug. 12 10 8 80.0 12 11 91.6 + 11.6 July 26 20 20 100.0 15 15 100.0 00.0 July 26 24 22 91.6 16 hour 20 exposure 19 95.0 + 3.4 Feb. 18 1 5.5 15 10 66.6 + 61.1 Mar. 6 17 4 23.5 16 11 68.7 + 45.2 Mar. 1 14 1 7.1 21 20 95.2 + 88.1 July 29 13 4 30.7 15 9 60.0 + 29.3 July 29 13 4 30.7 14 10 71.4 + 40.7 Aug. 1 12 4 33.3 18 14 77.7 + 34.4 Aug. 1 17 2 11.8 24 hour 13 exposure 10 77.9 + 66.1 Aug. 8 20 6 30.0 20 17 85.0 + 55.0 Aug. 8 17 2 11.7 13 8 61.5 + 49.7 Aug. 3 15 0 0.0 28 14 50.0 + 50.0 Notes: Formula No. 1 — Derris (5% rotenone) 10 grams, pyrophyllite 90 grams. No. 15 — Derris (5% rotenone) 10 grams, Hall clay (red) 90 grams. Table 22. Comparison of Different Strengths Rotenone in Red and White Carriers, Each Exposed 24 Hours to Sj Mazda Sun Lamp. Experiment Number of replicated tests Carrier % rotenone Average mortality 48 hrs. 1 6 Pyrophyllite (white) .5 49.2 2 6 " 1.0 58.2 3 5 a 2.0 89.4 5 4 Hall Clay (red) .25 40.7 6 5 .50 70.5 7 4 1.0 92.5 344 Connecticut Experiment Station Bulletin 445 Table 23. Result of Chemical Analyses1 for Light Exposed Rotenone Dusts Compared with Unexposed. Carrier Color Exposure to sun lamp Weight on slides Rotenone found % rotenone Pyrophyllite White None Averages Pyrophyllite White 24 hours Averages 00652 gm, Hall Clay Red None .0066 gm. .0062 .0072 .0074 Averages 00685 gm Hall Clay Red 24 hours .0072 gm. " " .0072 " " .0065 " " .0064 Averages 00682 gm .0061 gm. ■ .00016 gm. 2.5 .0053 .00011 2.0 .0069 .00019 2.8 .0057 .00019 2.9 .0060 gm. .000156 gm. 2.5 .0065 gm. .00005 gm. .8 .0062 .00007 1.2 .0066 .00009 1.3 .0068 .00008 1.2 .00007 gm. 1.1 .00014 gm. 2.1 .00011 1.8 .00016 2.2 .00017 2.3 .000145 gm. 2.1 .00010 gm. 1.4 .00012 1.6 .00010 1.5 .00010 1.6 .000102 gm. 1.5 Percentage reduction of rotenone by 24-hour sun lamp exposure: Hall Clay (red) 28.6 Pyrophyllite (white) 57.3 Difference in favor of Hall Clay 28.7% 'Chemical analyses by Dr. H. J. Fisher of the Dept. of Analytical Chemistry. Experimental Control of the Apple Maggot 345 Table 24. Control of Apple Maggot — 1940. Burton Orchard, Mount Carmel. Variety — Gravenstein. Tree Number cut open Infested % infested Treatment Picked fruit 14 155 12 7 1 200 12 6 2 160 6 3 3 180 25 13 4 180 13 7 5 140 6 4 6 160 20 12 7 160 20 12 5 ( 8 180 10 5 9 200 9 4 Jul 10 239 3 1 11 170 11 6 12 120 20 16 13 100 3 3 14 155 12 7 5 dusts of oil-rotenone-pyrophylliie July 5, 15, 25, August 1, 14 Totals 2344 170 7.2 Dropped fruit 1 160 34 21 2 120 23 19 3 160 40 25 4 120 26 26 5 100 21 21 6 120 20 17 7 160 41 24 8 160 90 56 S.rr 9 160 41 31 ban 10 140 36 26 11 140 33 24 12 100 25 25 13 40 12 30 14 100 20 20 Totals 1780 462 25.9 Same as above. Checks 120 105 Picked and Drops 87.5 None 346 Connecticut Experiment Station Bulletin 445 Totals Table 25. Control of Apple Maggot — 1940. Westwoods. Variety — Cortland. Number % Tree cut open Infested infested Treatment Picked fruits — ■ Dusted B 1 1 200 131 65.5 B2 2 150 130 86.6 B3 3 200 189 94.5 B5 4 200 122 61.0 B7 5 200 81 40.5 B9 6 200 140 70.0 6 dusts of .5% oil-rotenone dust B 11 7 B 13 8 200 200 107 140 53.5 70.0 July 5, 15, 25, August 1, 8, 26 B 15 9 200 88 44.0 B17 10 200 148 74.0 B 19 11 200 96 48.0 Totals 2150 1372 63.7 Picked fruits Gain + 35.6% in sound fruit — Check D 3 12 140 140 100 D 19 13 55 54 98 O20 14 300 300 100 L 15 15 L 17 16 200 200 199 199 99 99 No maggot sprays or dusts L 21 17 200 200 100 1095 B2 2 100 B5 4 100 B9 6 100 B13 8 100 B17 10 100 1092 99.3 Infestation in dusted plot during 1939 94 94 97 97 97 97 99 99 No maggot sprays or dusts 99 99 Totals 500 486 97.2 NOTES: Treatment covered 29 trees out of approximately 180 in the orchard. Additional sources of infestation included orchards on neighboring property only a short distance from the dusted plot. Crop in 1940 about H tnat or 1939. Table 26. Apple Maggot Control, 1938-1940. Burton Orchard, Mount Carmel. Variety — Gravenstein. Kind of Percent injured Treatment Year fruit by maggots .5% rotenone dust 1938 Drops 37 4 applications 1938 Picked 16 .5% rotenone-oil-pyrophyllite dust 1939 Drops 21 4 applications 1939 Picked 3 .5% rotenone-oil dust 1940 Droos1 26 5 applications 1940 Picked1 7 'Checks in this orchard during 1940 showed 87.5 percent infested fruit. All fruit dropped from the trees before counts could be made. Notes on the Codling Moth 347 NOTES ON THE CODLING MOTH IN CONNECTICUT Philip Garman Compared with other localities, the abundance of the codling moth in Connecticut is normally low. The reason for this situation is obscure but is probably linked in some way with climate or natural enemies, or both. Cool temperatures at sundown probably have con- siderable influence. Dampness and rainfall may also be important. We learn on reviewing the literature that outbreaks threatened dur- ing the period between 1871 and 1873. At that time P. M. Augur, Connecticut Pomologist, reported that the "Codling moth was par- ticularly destructive in last year's fruit. The depredations of this insect are becoming more and more general." Since then we find relatively few references to it in Connecticut literature though it is mentioned in Connecticut Entomological Reports for 1903, 1904, 1917, 1920, and 1925. Experiments by Messrs. Stoddard and Zappe in 1926 indicate that an infestation of about 26 percent developed on check trees near a packing shed. This is the highest figure we have seen until last summer when one of our check trees at Mount Carmel went to 29 percent. About the only similarity in the weather between 1871 to 1873 and 1940 is the fact that all were in periods of abnormally high summer temperatures. The earlier period lasted from 1860 to 1880, whereas the present period apparently began about 1930. Whether or not temperatures are the primary influence, it will be noted that both records of infestation came about 10 years after the beginning of the warmer summer averages. The worst infesta- tion that I have yet seen in Connecticut occurred this year in Middle- field. In the orchard mentioned, about three acres of Mcintosh were so heavily infested that the owner put in his thinning crews and picked off and destroyed all fruits. The trees in a block of some 10 to 15 acres were then scraped and banded, as well as dusted, to catch any late stragglers of the second generation. How effective this program will be remains to be seen, but the grower concerned is energetic and resourceful and, if it is at all possible, will get control of the situation. The infestation occurred on a relatively high knoll near a pack- ing shed. No signs of moths could be seen within the shed in spite of the fact that it was filled with apple crates at the time of inspec- tion. Alongside the shed were piled a number of cords of wood, mainly trunks of apple trees removed from another part of the same orchard. The stumps were two years old, however, which should eliminate them as a source of trouble this year although they might have concentrated the moths during 1939. The owner admits that some of the early sprays were skipped in 1940, and at the time of inspection little spray deposit could be found on the trees. Possibly this may be a more serious element tending to build up the population than any others, but it is evident 348 Connecticut Experiment Station Bulletin 445 that the insect is on the increase over the entire area, 100 - 150 acres. If the increase is due to high summer temperatures and these tem- peratures continue, the trouble will continue. Also, if the strain of codling moth proves to be imported from other localities where the insect is more vigorous, trouble may be expected to continue. If, on the other hand, it is merely due to concentration of moths and orchard practices, we look for a decline to its original status before long. At least two other growers have reported codling moth damage in 1940, and the situation will doubtless be watched with increasing interest by many Connecticut growers during 1941. OBSERVATIONS ON THE EUROPEAN CORN BORER (Pyrausta nubilalis Hubn.) R. L. Beard To achieve satisfactory control of an insect by chemical means it is essential for the insecticide to be applied in the proper place at the proper time. In the case of the European corn borer (Pyrausta nubilalis Hubn.), standard procedure has been to apply dual-fixed nicotine dust to the developing whorl and to the leaf axils at five- day intervals, beginning soon after the eggs hatch. The application of the dust to the whorl and to the leaf axils, particularly those in which the ears form, is based on such observations as reported by Neiswander, Polivka, Balduf, and Huber.1 These workers noted that although the feeding habits change somewhat coincident with changes in the correlation between the development of the corn and the development of the insect, in gen- eral the young borers feed into the whorl at the base of the unroll- ing leaves. As the tassel emerges, the young larvae feed in and among the pollen buds. As the tassel grows away from the leafy portions of the plant and spreads out, the larvae leave the tassel, some of them boring directly into the stem of the plant, where they remain. Other larvae move downward to enter the stalk at a point under a leaf sheath or feed in the angle formed by the base of the leaf and the stalk. Presumably these latter larvae are those which later infest the ears, although the authors did not so specify. In order to determine for Connecticut the feeding habits of the corn borer with a view toward improving the effectiveness of insecti- cidal treatment, observations on both generations of the corn borer were made during the 1940 season. For the first generation borer, corn of the Marcross variety was planted on April 25 and May 1. As regards the feeding of the borer, the difference in plant growth due to planting dates was not sufficient to demand separate considerations of the two lots. Three procedures were followed in tracing the activities of the borers. In one, 70 plants were dissected in groups of 10 at five- aIn Huber, L. L., Neiswander, C. R., and Salter, R. M. 1928. The European Corn Borer and its Environment. Ohio Agr. Expt. Sta., Bui. 429. Observations on the European Corn Borer 349 day intervals following the first hatching of corn borer eggs. After the first eggs hatched, subsequent eggs deposited were removed by frequent examination of the plants. In another series of 40 plants on which the first eggs alone were allowed to hatch, dissections in groups of 10 were made when the plants reached certain stages of growth, namely, plants having early ear shoots, those in silk, at the time of harvest, and plants with corn in the hard dough stage. In the third series, eggs were allowed to hatch on certain plants at one time, and on other plants at other times in such a way that through- out the oviposition season of the insect, different groups of plants became infested at different times. Portions of each group were dissected at intervals in point of time rather than at particular growth stages. At the time of dissection the stage of growth of the plant was noted and all borers were recorded both as to stage of development and as to position on the plant. In an effort to decrease migration from plant to plant, plants adjacent to those under observation were kept free from eggs except in such cases in which the infestation coincided in time with that of the observed. Although the plants were very carefully examined at intervals frequent enough to observe eggs before hatching, it was found that an occasional egg-mass was overlooked. Moreover, it was impos- sible to distinguish individual borers which had migrated from plants other than those under observation except in instances where age differences were obvious. Accordingly, the data presented here show trends and not absolute relationships, particularly when comparable populations, rather than identical populations, are measured at differ- ent times. One further qualification must be made. Although 325 corn plants were dissected for the first generation borer alone, so many categories were considered that the number of plants in each was small, and in most cases the number of borers was such that the expression of the data in terms of percent represents an extension of the observed figures, and must be considered as such. Although the first eggs to be deposited must necessarily be placed on the main portion of the plant, tillers soon develop upon which eggs are commonly laid. The effect of this upon the ultimate distri- bution of the borers is important in that marketable ears of corn are produced on the main stalk. On plants observed for the first gen- eration borer, 1,842 eggs on the main portions of the plant were recorded. Dissections of the plants yielded a total of 484 borers, of which 22 percent were located in the tillers, and 78 percent in the main plant. On the other hand, 1,309 eggs were noted on the tillers of other plants. These plants upon dissection yielded 379 borers, of which 54 percent were located in the tillers and 46 percent in the main portion of the plant. These figures suggest that regardless of the position of the eggs, the borers hatching therefrom tend to dis- tribute themselves over the whole plant, but there appears to be a greater tendency for the borers borne on the main plant to remain on the main plant than there is for the tiller-borne borers to remain on the tillers. In other words, the main stalk is apparently more attractive to the larvae. Tillers, on the other hand, appear more 350 Connecticut Experiment Station Bulletin 445 attractive for oviposition, as judged from a consideration of 140 egg-masses, of which 86 were deposited on tillers and 54 on the main plant. (Only plants possessing tillers were included for these figures.) At the time of harvest. 100 infested ears of corn were examined, and the position of borer entrance was noted. In only one case had a borer reached the ear by boring from the stalk through the shank of the ear. In three cases infestation was by way of the silk. In 39 cases, entrance to the ear was made at the area of contact be- tween the ear and the stalk. And in the remaining 57 cases, the borers entered through the exposed portions of the husk. These figures show that the possibility of borers resident in the stalk itself reaching the ear by boring through the shank is a negligible factor. In the tabulations below, the infestation of borers in the ears and ear shoots is that with which we are most concerned. The in- festation of the leaf sheaths immediately surrounding the potential ears is likewise important in that the borers are there readily avail- able for ear attack. Although the borers in that portion of the main stalk supporting the potentially marketable ears are recorded separately, there is little real need for it for the reason mentioned above: that larval migra- tion from the central stalk to the ear is negligible. In fact, observa- tion indicates that normally, borers have little tendency to leave the stalk once they become established there. All other portions of the main stalk are grouped together, and all parts of the tillers are considered as a unit. The following tabulation represents, at each of four stages of plant growth, the percent infestation of these plant regions, based on the total number of borers in 10 corn plants. Only the first eggs deposited were permitted to hatch. Table 27. Distribution of Borers in Plants at Different Growth Stages. Plants Infested Early in Season. Stage of growth Ear Shoot Silk Time of Hard dough harvest Number of borers 61 114 89 41 Position of borers in plant: Ears and ear shoots 5% Leaf sheaths around ears Portion of stalk supporting ears Other portions of main stalk 79 Tillers 16 100% 100% 100% 100% 18% 33% 17% 6 2 5 1 14 34 42 12 27 33 39 17 Observations on the European Corn Borer 351 These figures show, for the first three stages of plant growth, an increasing concentration of borers in the ears, ear shoots, adjacent parts of the stalk, and in the tillers, with a corresponding decrease in the other portions of the main plant. The 70 plants dissected in groups of 10 at five-day intervals following the first hatching had borers distributed as follows: Table 28. Distribution of Borers in Plants at Different Times After Initial Infestation. Days after first hatching 5 10 15 20 25 30 35 Number of borers 35 56 87 58 62 90 44 Percent borers found in: Ears and ear shoots 2% 10% 14% 36% 21% 32% Leaf sheaths around ears .... 1 7 .... 1 Portion of stalk supporting ears 1 8 18 26 25 Other portions of main stalk 89% 80 34 54 27 15 25 Tillers 11 18 54 17 19 37 18 100% 100% 100% 100% 100% 100% 100% These data show the same general tendency, though less definite than the above, of an increasing concentration of borers in the ears. The borer infestation in the tillers shows no definite trend. If these same data are considered in terms of stage of plant growth at the time dissections were made instead of units of time, the following relationships pertain: Table 29. Distribution of Borers in Plants at Different Growth Stages After Initial Infestation. Stage of growth Early Tassel Ear shoots. Silk. No Ears No silk real ears Number of borers 54 70 96 212 Percent of borers found in: Ears and ear shoots 6% 11% 27% Leaf sheaths around ears .... 5 Portion of stalk supporting ears .... 5 22 Other portions of main stalk 92% 64 37 23 Tillers 8 30 42 28 100% 100% 100% 100% This treatment of the data emphasizes the concentration of the borer population in the ears coincident with a progressive decrease in the proportion of borers found in the other portions of the plants as growth occurs. 352 Connecticut Experiment Station Bulletin 445 The data covering dissections of corn infested at different times throughout the oviposition period of the borer adult are summarized as follows: Table 30. Distribution of Borers from Eggs Deposited June 4-9. Date of dissection 6/24 6/28 7/3 7/8 7/16 7/19 7/26 7/29 8/2 Number of borers 8 12 6 22 32 27 34 9 16 Percent of borers found in: Ears and ear shoots 17% 23% 22% 11% 53% 56% 12% Leaf sheaths around ears .... .... .... .... 4 3 .... 6 Portion of stalk sup- porting ears .... .... .... 22 7 12 22 19 Other portions of main stalk 88% 100% 83 73 28 45 23 11 19 Tillers 12 4 28 33 9 11 44 100% 100% 100% 100% 100% 100% 100%, 100% 100% Table 31. Distribution of Borers from Eggs Deposited June 10 - 14. Date of dissection 6/24 6/28 7/3 7/16 7/24 7/29 8/2 Number of borers 13 3 23 43 25 9 48 Percent of borers found in: Ears and ear shoots 16% 24% 45% 15% Leaf sheaths around ears .... 4% Portion of stalk supporting ears .... .... .... 16 20 22 21 Other portions of main stalk.... 100% 100% 35 28 36 11 25 Tillers 61 40 20 22 39 100% 100%, 100% 100%, 100% 100% 100%, Table 32. Distribution of Borers from Eggs Deposited June 14 - 20. Date of dissection 6/28 7/8 7/16 7/19 7/26 7/29 Number of borers 3 36 36 34 26 53 Percent of borers found in: Ears and ear shoots 8% 25% 44% 11% 28% Leaf sheaths around ears .... 3 3 4 Portion of stalk supporting ears .... 3 6 4 19 Other portions of main stalk 100% 64 2 21 27 19 Tillers 28 67 26 54 34 100% 100% 100% 100%, 100% 100%, Observations on the European Corn Borer 353 Table 33. Distribution of Borers from Eggs Deposited June 21 - 27. 7/13 Date of dissection 7/16 7/25 8/2 Number of borers 13 Percent of borers found in: Ears and ear shoots 39% Leaf sheaths around ears Portion of stalk supporting ears Other portions of main stalk 15 Tillers 46 24 34% 4 4 25 33 23 17 4 57 100% 100% 100% 32 22% 28% 31 31 10 100%, Table 34. Distribution of Borers from Eggs Deposited June 28 - July 1. Date of dissection 7/8 7/20 7/29 Number of borers 26 Percent of borers found in: Ears and ear shoots 19% Leaf sheaths around ears Portion of stalk supporting ears Other portions of main stalk 8 Tillers 73 100% 36 36% 3 8 11 42 47 30%, 19 26 25 100% 100% Table 35. Distribution of Borers from Eggs Deposited July 2-5. Date of dissection 7/15 7/25 8/2 Number of borers 43 Percent of borers found in: Ears and ear shoots 23% Leaf sheaths around ears 2 Portion of stalk supporting ears Other portions of main stalk 12 Tillers 63 59 22% 3 9 10 56 34 17% 15 9 59 100% 100% 100%, 354 Connecticut Experiment Station Bulletin 445 Table 36. Distribution of Borers from Eggs Deposited July 6 - 10. Date of dissection 7/20 7/29 Number of borers 6 Percent of borers found in: Ears and ear shoots 50% Leaf sheaths around ears Portion of stalk supporting ears Other portions of main stalk Tillers 50 100% 30 27% 13 20 40 100% In the above, the ears and ear shoots were considered together. An infestation in the ears or ear shoots destined to form marketable ears is of more serious nature than one later in the season in a rudi- mentary ear which will never reach maturity. In the corn used in this experiment, five ear shoots commonlv form, the first one of which regularly develops into a marketable ear, the second one usually does, and the third infrequently does. Inasmuch as the best ear develops from the first ear shoot to appear, it is available for insect attack for a somewhat longer period of time than the other ear shoots. This results in a relatively greater infestation in the poten- tial ears than in the other ear shoots, as can be seen from a consid- eration of 170 corn plants on each of which were present two poten- tial ears and from none to four additional ear shoots. The infesta- tion of the ears and rudimentary ears is tabulated as follows: Table 37. Borer Infestation in Ears Relative to Number of Ear Shoots Present. Number Number of borers Number of borers of in two ears or in all other plants potential ears ear shoots Plants with: Two ears, no ear shoots 46 Two ears, one ear shoot 87 Two ears, two ear shoots 27 Two ears, three ear shoots 6 Two ears, four ear shoots 4 55 83 21 9 20 25 6 10 6 Analysis of detailed data clearly shows that, in the early stages of plant growth, the green tassel is the most attractive region of the plant to the borers. Most of the newly hatched larvae immediately seek that structure, in most cases penetrating the pollen buds, there to remain embedded until the third or even fourth larval instar is reached, when the borers migrate downward. Although, as Neis- Observations on the European Corn Borer 355 wander (et al, I.e.) found, this migration was correlated with the spreading out and yellowing of the tassel, it is not clear whether the stage of plant growth, the stage of insect growth, or the exhaustion of food is responsible for the larval movement. A point of interest, but one difficult of estimation, is the propor- tion of the larvae involved in this migration which reach the various regions of the plant. The tillers appear to absorb a large proportion of the migrating larvae. If it is assumed, in those tabulations above in which borer eggs were deposited early in the season, that the increase in borer population in the ears and ear shoots is due entirely to this migration, the figures, as given, represent the proportion for these plant structures. Certainly the chief source of the borers in the ears of plants early infested is from the tassel buds. A certain amount of migration from other plants may account for some of the borers in ears, but it is reasonable to suppose that emigration from one plant compensates for immigration from others. The possibility of a primary infestation of the ears by borers from eggs overlooked in routine examination of plants is minimized by the fact that the detailed data show few larvae younger than the third instar present in the ears. In plants infested later in the season, when ears are developing on the plants, a marked attraction for the borers is noted in the ear shoots. For the corn under consideration, June 20 dated the begin- ning of ear shoot development, and it is obvious from the tabulations above that plants infested after this date showed a large primary infestation in the growing ears, and that the attraction of these structures for the borer superceded that of the tassels. That the infestation of ears was primary and not a result of migration is evi- denced by the fact that the larvae present at the first dissections after attack were predominantly in the first or second instar. It may be stated summarily, then, that in the early stages of plant growth, the chief infestation by the corn borer occurs primarily in the tassel and the subsequently developing ears become secondarily infested by the migrant larvae from the tassels. If, however, ear shoots are present at the time the corn borers hatch, they become primarily infested and the tassels no longer are attractive to the young borers. According to the oviposition trend based on observations of 20 hills of corn in an adjacent plot by the Bureau of Entomology and Plant Quarantine of the U.S.D.A., approximately 30 percent of the corn borer eggs of the first generation presumably hatched before ear shoots were present on the plants. Consequently, borers result- ing from these eggs infested the developing ears only secondarily. The bulk of the eggs hatched subsequent to June 20, the ears then being infested directly. The peak of oviposition occurred between June 17 and June 20. Similar observations on the second generation of corn borer 356 Connecticut Experiment Station Bulletin 445 were made on Golden Cross Bantam corn planted about June 25, and on Carmelcross planted on July 2. By the time the borers started feeding, the corn was well developed with ear shoots appearing. Bearing out the observations on the first generation borer, the corn tassels lost their attraction for the larvae coincident with the development of ear shoots. Because of this, the ears, with minor exceptions, showed a relatively uniform percent infestation through- out the season, suggesting that the infestation was primary. This is seen in the following tabulation, in which only the infestation in the potentially marketable ears is considered: Table 38. Second Generation Borer Infestation in Ears. All eggs deposited allowed to hatch. Time dissected, in days after first infestation 10 days 15 days 20 days 25 days 30 days Total borers present in 10 plants .... 79 56 84 115 83 Percent borers in potential ears 11% 5% 19% 10% 11% All eggs deposited allowed to hatch. Stage of plant at time of dissection Ear shoot Silk Harvest Total borers present in 10 plants 90 92 128 Percent borers in potential ears 0 3% 20% Plants infested August 5-9 Date of dissection 8/22 9/5 9/10 9/13 9/16 9/26 Total borers present in plants dissected.. 26 89 77 33 65 133 Percent borers in potential ears 12% 10% 10% 15% 12% 9% Plants infested August 10-15 Date of dissection 9/2 9/5 9/9 9/13 9/17 9/22 Total borers present in plants dissected.. 36 27 35 53 76 89 Percent borers in potential ears 11% 44% 34% 38% 12% 26% Plants infested August 16-22 Date of dissection 9/5 9/13 9/17 9/22 9/26 Total borers present in plants dissected.. 11 25 38 22 51 Percent borers in potential ears 18% 12% 3% 23% 16% Plants infested August 23 - 27 Date of dissection 9/11 9/26 Total borers present in plants dissected.. 22 40 Percent borers in potential ears 32% 10% The application of the information obtained in this study will depend upon further observations involving the reactions of larvae of different stages to insecticide placed in restricted regions of the plant. But the fact that in 1940 the ears were primarily attractive to first generation larvae, when 70 percent of the borer population was being established, and secondarily attractive when only 30 per- cent was being established, may explain in part the favorable results in control obtained by Turner1 in spraying the ears alone, leaving the rest of the plant untreated. 'See pp. 358-359. European Corn Borer Insecticide Investigations 357 EUROPEAN CORN BORER INSECTICIDE INVESTIGATIONS Neely Turner A large-scale experiment in controlling the European corn borer (Pyrausta nubilalis Hubn.) by means of dusts was carried out on early market sweet corn. A detailed account of this test has been submitted for publication elsewhere. In brief, it proved both practical and profitable to dust such corn. When dual-fixed nicotine dust (the more effective material) was used, treated corn sold for $343.00 an acre and the cost of treatment was estimated at $42.50. Corn from untreated plots sold at the rate of $100.00 an acre for borer-free corn only, and infested untreated ears could be sold only with difficulty. Grading corn as borer-free and infested was suc- cessful because the borer-free ears brought a premium price on the market. The technical studies of insecticides were made on small plots of sweet corn, in both the first and second generations. The plots for hand application were four rows wide and 25 feet long, and those for machine application were 50 feet long. The design was one of randomized plots in replicated blocks. The sample for results was 20 plants taken at random from the two inside rows of each plot and dissected to determine the number of borers. There were two untreated plots in each block to afford adequate numbers for comparison with treated plots. Hand application of dusts was made with a knapsack bellows duster. For machine application, a power, two-row, self-propelled duster was used. Compressed air hand sprayers were used in the spray tests. The infestation of corn borers was lower than in previous years. The cool spring weather retarded development somewhat. The early emergence of moths appeared to be normal in numbers. How- ever, exceptionally cool weather late in June prevented a large in- festation. The second generation developed more normally but was still fewer in numbers than usual. Rainfall was abundant but did not interfere seriously with the schedules. First Generation Tests Two fields were used in these tests. In Field I dual-fixed nico- tine dust (the commercial preparation containing not less than 3.75 percent nicotine) and derris dust (commercially prepared, containing 358 Connecticut Experiment Station Bulletin 445 1 percent rotenone) were compared. Both dusts were applied by machine and by hand to wet foliage in the early morning and to dry foliage in late evening. The dates of application were June 11, 16, 21 and 27-28. The evening series of the last treatment was applied June 27 and the morning series on "the following day. A summary of the results is given in Table 39. Statistical analy- sis of the results showed that hand application was significantly bet- ter than machine, and that dual-fixed nicotine dust was more effec- tive than derris dust. The difference between application to wet and dry foliage was suggestive but not statistically significant. Table 39. Summary of Results — Field I. Treatment Number larvae % reduction in 100 plants of borers % No. 1 ears borer-free Dual-fixed nicotine dust by hand on dry leaves 98 by hand on wet leaves 141 by machine on dry leaves 134 by machine on wet leaves 173 Derris dust by hand on dry leaves 176 by hand on wet leaves 167 by machine on dry leaves 184 by machine on wet leaves 221 No treatment 336 70.7 77.0 58.0 74.6 60.0 58.8 48.4 59.8 47.6 72.4 50.3 64.6 45.1 57.1 34.2 56.4 37.9 In Field II both dual-fixed nicotine and derris dusts were applied by hand: (1) four applications at intervals of five days (June 13, 18, 25 and 30); and (2) three applications at intervals of seven days (June 13, 21 and 30). Pure ground derris root (4.7 percent rote- none) was used in the same schedules, mixed with the Ultrawet spreader at the rate of two ounces to a pound of derris root sus- pended in 25 gallons of water. Applications of a spray to the ears only were made on June 28, when young ear shoots had formed; July 8, just prior to silking; and July 15, when the ears were in full silk. Two varieties of early corn, Spancross and Marcross, were used, with four blocks of plots in each variety. European Corn Borer Insecticide Investigations 359 Table 40. Summary of Results — Field II. Number larvae % reduction % No. 1 ears Treatment in 100 plants of borers borer-free Spancross Dual-fixed nicotine dust 4 applications, 5-day interval 66 82.2 76.7 3 applications, 7-day interval 121 67.5 64.4 Derris dust 4 applications, 5-day interval 141 62.2 57.9 3 applications, 7-day interval 188 49.8 60.6 Derris spray 4 applications, 5-day interval 110 70.9 64.5 3 applications, 7-day interval 196 47.5 48.5 3 applications, ears only 64.2 No treatment 374 38.6 Marcross Dual-fixed nicotine dust 4 applications, 5-day interval 129 71.3 66.7 3 applications, 7-day interval 117 73.8 62.7 Derris dust 4 applications, 5-day interval 169 62.4 52.1 3 applications, 7-day interval 303 32.3 30.0 Derris spray 4 applications, 5-day interval 221 50.7 42.9 3 applications, 7-day interval 120 73.2 67.6 3 applications, ears only 59.7 No treatment 449 37.7 A summary of the results is given in Table 40. Statistical analysis of the combined results from the two varieties showed that in the dust tests four treatments at intervals of five days were more effective than three applications at intervals of seven days. In the spray test, the reversal of results on Spancross and Marcross was unexpected and inconclusive. The application of spray to ears only was surprisingly effective. Second Generation Tests In these tests dual-fixed nicotine dust was applied by hand in comparison with the machine, and to wet and dry foliage on a stand- ard schedule of five applications at intervals of five days (August 12, 360 Connecticut Experiment Station Bulletin 445 17, 22, 27 and September 2). Hand applications were also made at intervals of seven days on wet and dry foliage (August 12, 19, 26 and September 1 ) . In addition two materials were tested by hand applications on dry foliage on the five-day schedule: ( 1 ) a dust made of 2.5 pounds Agicide Concentrate and 7.5 pounds pyrophyl- lite (approximately .15 percent rotenone and .5 total extractives); and (2) a commercially prepared dust of Dry Pyrocide labelled No. 10 (.2 percent pyrethrins). The results are summarized in Table 41. Machine applications were significantly better than hand, and application to wet foliage gave better (but not statistically significant) results than to dry. Four applications at intervals of seven days were as effective as five applications at intervals of five days. Derris, Dry Pyrocide and Agicide dusts were significantly less effective than dual-fixed nico- tine dust. Table 41. Summary of Results — Second Generation. Number larvae % reduction % No. 1 ears Treatment in 100 plants of borers borer-free Dual-fixed nicotine dust 5-day schedules by machine on dry leaves 175 by machine on wet leaves 105 by hand on dry leaves 217 by hand on wet leaves : 217 7-day schedules by hand on dry leaves 205 by hand on wet leaves 187 By hand on dry leaves — 5-day schedules Derris dust 337 Dry Pyrocide dust 404 Agicide dust 428 No treatment 828 Discussion. The most consistent difference was that between dual-fixed nicotine and derris dusts, which was uniform in all tests. In the first generation there were definite indications that the stan- dard four applications at intervals of five days were more effective than three applications at intervals of seven days. No such differ- ence occurred in the second generation tests. The results regarding application to wet and dry foliage are somewhat in conflict, but at least it can be concluded that evening applications may be as satis- factory as those made early in the morning. 78.8 78.4 87.3 84.0 73.7 74.4 73.7 74.9 75.2 78.0 77.3 77.7 59.3 64.3 51.2 53.7 48.2 55.8 37.6 Control of the Cabbage Maggot 361 The more effective use of the machine as compared with the hand duster in the second generation might well be due to better operation and adjustment of outlets. The first generation tests were made with the new machine of a type which had not been available previously. One very encouraging result was the comparatively high effec- tiveness of the spray applied to ears only. This will be investigated further since it offers a less expensive treatment than the standard applications of sprays or dusts. CONTROL OF THE CABBAGE MAGGOT Neely Turner The cabbage maggot {Hylemyia brassicae Bouche) is by far the most destructive insect pest of early cabbages, cauliflower and related crops in Connecticut. In some seasons few maggots appear, but as a general rule enough are present to justify treatment every year. The development of the bichloride of mercury treatment has enabled growers to control the cabbage maggot successfully. How- ever, this material is difficult to dissolve and handle in the field, because only wooden, glass or enameled containers can be used to handle the solution. Furthermore, the solution injures roots of young or newly-set plants (Glasgow, 1929). The search for other effec- tive materials resulted in the discovery by Glasgow that calomel (monochloride of mercury) is a satisfactory chemical. Furthermore, calomel has been used successfully in dust form, which eliminates the necessity of handling quantities of water. The standard practice has been to apply a dust containing 4 percent calomel diluted with 96 percent talc, clay, or gypsum around the stem of the plant two or three times during the egg-laying period in May. This appears to be a simple control measure, but many growers have not obtained satisfactory results. Application too late to protect the plants has been the most common failure, with use of a much too small amount of dust of almost equal importance. Glasgow also demonstrated that pure calomel applied to the stems of plants before setting is effective, providing the coating is not destroyed during the planting operation. In actual practice the coating of calomel is usually broken or destroyed during planting. For this reason a series of tests was started, using other methods of application. In 1938 the roots of plants ready for setting in the field were dipped in calomel dust just before planting. For comparison, a tea- spoonful of calomel dust was placed around the stems of the plants immediately after setting. Both treatments were effective, and the application of dust around the stem after setting seemed to be more practical from the growers' standpoint. In 1939 this method was compared in a preliminary test with the standard treatment of two applications of dust around the stem of the plants during the ovipo- 362 Connecticut Experiment Station Bulletin 445 sition period in May. The planting time application was made by hand and the May treatments by a small hand duster of a type used commonly by growers. The treatment at planting time was more effective in controlling cabbage maggots than the surface applica- tions. In 1940 the tests were made on a larger scale in randomized plots. The treatments were applied to Copenhagen Market cabbage, set April 25, as follows: 1. Four percent calomel mixed with 96 percent Bancroft clay, applied by hand to the surface of the ground around the stem of each plant immediately after setting. Material was used at the rate of 106 pounds to the acre. 2. A similar treatment using 8 percent calomel, at the rate of 96 pounds to the acre. 3. Surface treatments on May 14 and 24, using 4 percent calomel dust applied by a small hand duster. The total amount of dust used in both applications was 66 pounds. 4. No treatment. Each treatment was applied to six plots and a plot consisted of two rows of 10 plants each. The heads were harvested as they matured, and records kept of the weight per row. A summary of the results is given in Table 42. Analysis of variance of the origi- nal figures on which the summary is based showed highly significant differences between treated and untreated in regard to number of heads and total yield, and no difference between number of heads and yield among the three treatments. Table 42. Yield of Cabbage and Maggot Treatment. Average weight Treatment Number heads Total weight per head (lbs.) (lbs.) 4% calomel — planting time 115 8% calomel — planting time 115 5% calomel — May treatment 112 No treatment 81 Discussion. The amount of calomel per acre applied by surface application was slightly more than half that used in planting time treatments. There is no information in this experiment to indicate the minimum amount of calomel necessary to protect the plants. The facts that surface treatment with a smaller amount of material was effective, and that increasing the amount of calomel from 4 percent to 8 percent was unnecessary, indicate that the planting time dosage might be reduced. Regardless of this point it is evident that surface treatments at planting time were effective. The planting time treat- ment is highly advantageous to the grower. It avoids the always difficult task of timing May applications during the oviposition dates 302.31 2.63 325.44 2.83 312.06 2.79 196.12 2.42 The Japanese Beetle, Seasonal Development — Sprays 363 of the maggot flies. It enables the grower to complete planting and treatment in one operation. When the plants are small it is much less trouble to apply the dust around the stems than when they have grown larger. Furthermore, the month of May is perhaps the busiest of the year for the average vegetable grower, and transfer of the treating date for cabbage to April should be a distinct advantage. Summary. The two preliminary tests followed by a larger scale plot test have demonstrated that an application of 4 percent calomel dust around the stems of newly-set cabbage plants is a satisfactory treatment. Such an application is as effective as the standard treat- ments usually applied in May. Literature Cited Glasgow, Hugh, 1929: Mercury salts as soil insecticides. Jour. Econ. Ent., 22: 335-340. SEASONAL DEVELOPMENT OF THE JAPANESE BEETLE AND SPRAYING FOR THE ADULT INSECT J. Peter Johnson Several lots of immature stages of the Japanese beetle were obtained from diggings made in Bridgeport and New Haven during the month of June, 1940. The majority of the insects were in the third larval instar, but prepupae and pupae also were present. The results of the diggings are given below. Table 43. Results of Spring Diggings, 1940. 3rd Instar Location Date Larvae Prepupae Pupae Total East Rock Park, North End, New Haven June 12 East Rock Park, Rice Field, New Haven June 19 Municipal Golf Course, New Haven June 19 Seaside Park, Bridgeport June 19 The most advanced stages were found at the Municipal Golf Course, and the place where the diggings were made was in a pro- tected area having a southern exposure. None of the pupae were in the advanced stage. The adult beetles began to emerge from the soil approximately two weeks later than usual in the summer of 1940. This was probably due to adverse temperature and moisture conditions earlier in the season. April had a mean temperature (Hamden) of 3° F. below normal and the precipitation was about normal. The mean temperature for May was 1° F. below normal while the precipita- tion was about three times normal. During June the mean tempera- 46 21 4 71 29 24 6 59 18 18 34 70 66 14 4 84 364 Connecticut Experiment Station Bulletin 445 ture was 1° F. below normal and the precipitation was about nor- mal. However, the coolest period during this last month occurred between June 20 and June 27 at the time when the adult beetles usually emerge from the soil. During this period the daily mean temperature rose above 59° F. only twice and on one of these days it was 63° while three days later it was 61°. The first beetle reported in the vicinity of New Haven was found on July 6. For the next few days the beetles observed were few in number but on and after July 1 1 they were becoming more abundant. The beetles were abundant in old areas of infestation and continued to cause defoliation until about the first week in September. However, in localized areas beetles were numerous un- til October, feeding on low growing plants. The last adults were observed in the field on October 15. Freezing temperatures occurred for the next several nights and no further observations were made. As the beetles were late in emerging, the experimental spray program was delayed accordingly. The areas selected for spraying were situated in an urban section where many favorite host plants were growing and beetle feeding had been general the preceding season. One-half of a city block was selected as a unit for each spray, and all host plants, together with other non-attractive plants which were incidental in the group plantings, were sprayed. 1. Lead arsenate at the rate of 6 pounds, plus 4 pounds of wheat flour and 1 quart of soybean oil to 100 gallons of water was applied July 1 1 to the first unit. Among the host plants sprayed were sweet cherry, sassafras, Norway maple, Virginia creeper, linden and white birch. Heavy showers occurred only a few hours after the spray was applied, and heavy rains continued throughout the night and the next morning. Altogether 2.16 inches of rain fell within the 24 hours following the application. 2. The second unit was sprayed on July 13 with a mixture com- posed of 4 pounds of lead arsenate, 4 pounds of wheat flour, and 1 quart of soybean oil to 100 gallons of water. Sweet cherry, Chinese elm, white birch and mountain ash were among the host plants treated. 3. The third unit was sprayed on July 15 with a mixture of lead arsenate 4 pounds, wheat flour 4 pounds, water 100 gallons. Among the host plants treated were weeping willow, apple, Norway maple, Japanese red maple, althea and purple leaf plum. 4. The fourth unit was sprayed six times at intervals of seven days with pure ground derris root (containing 4 percent rotenone) at the rate of 6 pounds, plus 1 quart of rosin residue emulsion, to 100 gallons of water. The beetles were present in numbers suffi- cient to cause defoliation for a period of approximately six weeks. It was observed that the beetles would return in numbers to the most favored host plants, such as Chinese elm, roses and Virginia creeper, by the sixth and seventh day after each spray, and cause slight The Japanese Beetle, Seasonal Development — Sprays 365 additional damage. This would indicate that if it were desirable to obtain the best results with the derris spray, it would be necessary to make an application every fifth or sixth day, depending upon the degree of beetle infestation. A single application of the derris spray leaves very little visible residue, but as only 1.35 inches of rain fell (Hamden) during the period, the accumulated residue from the six applications was very noticeable. The units sprayed with the lead arsenate, flour, and soybean oil, and with the lead arsenate and flour mixture were adequately pro- tected and no appreciable damage occurred to treated foliage. Un- sprayed new growth was attacked and eaten on some of the primary host plants but this was not general. A few trees left unsprayed as checks were partially defoliated and the beetles attacked the fruit on unsprayed peach trees located on one of the properties. Due to the small amount of rainfall only one spray of these materials was applied. It would be necessary in seasons of heavy rainfall, when the spray was washed off the foliage, to make one or two additional applications. A number of trees, namely sassafras and mountain ash, in East Rock Park, New Haven, were sprayed July 15 with tetramethyl thiuram disulfide at the rate of 2 pounds, plus 2 pounds of pheno- thiazine, to 100 gallons of water. The sprayed sassafras foliage was definitely protected for a period of approximately two weeks. A small number of beetles then reinfested the foliage and the accumu- lative light feeding was apparent by the end of August. The un- sprayed new growth on most of the sassafras trees was attacked as soon as it developed. The mountain ash foliage was reinfested within a few days after being sprayed and some defoliation occurred before the end of the season. There was a total of 2.19 inches of rainfall (Hamden) from July 16 until September 10. Small amounts of rain fell on 17 different days, 0.66 inches being the largest amount on any one day. Observations were made in a commercial vineyard in Greenwich, where two applications of tetramethyl thiuram disulfide and pheno- thiazine were made approximately two weeks apart on one variety, the Delaware grape, which is very susceptible to Japanese beetle attack. The first application was made in the first week of July when the first adults were expected to emerge, and the second one was applied on July 16 when the insects were becoming very num- erous. On July 18 many beetles were observed throughout the area in which the vineyards were located. The sprayed vines were com- paratively free of infestation as only one beetle was observed on them. However, as the season progressed, the beetles returned and ate all of the new foliage and some of the older sprayed foliage. Sufficient of the older foliage remained to enable the fruit to mature, whereas in the preceding year it was reported that the vines were defoliated to such an extent that the grapes failed to develop properly. 366 Connecticut Experiment Station Bulletin 445 Beetles were more numerous than in preceding seasons, and defoliation occurred over larger areas. These conditions were very noticeable in Branford, Bridgeport, East Hartford, Greenwich, Ham- den, Hartford, New Haven and West Hartford. Nectarine and plum trees were defoliated in one orchard in Greenwich. Ripening peaches were eaten by the beetles in the same orchard, resulting in a considerable loss to the grower. The derris and rosin residue emul- sion mixture, used at the same rate as given above, was applied to a number of the trees attacked and protected the foliage and fruit for a period of five to six days. Below is a list of ornamental trees and shrubs sprayed during the season of 1940 with lead arsenate at 6 pounds, wheat flour 4 pounds, and soybean oil 1 quart to 100 gallons of water. Azalea amoena Bush honeysuckle Shrub-althea American linden Butterfly bush Dogwood, Flowering Dogwood, Red flowering Dogwood, Red osier Deutzia, Slender Birch, Gray Birch, European white Birch, Sweet Cherry, Sweet Crab, Flowering (white) Crab, Flowering (pink) Apple, Mcintosh Coralberry Forsythia, Border Forsythia, Weeping Kerria Hugonis rose Hawthorn, White Elm, American Elm, Chinese Elm, Dwarf Asiatic Apple, var. Hydrangea, Peegee Maple, Norway Maple, Japanese red Maple, Schwedler's Maple, Silver Maple, Sugar Lilac, Hort. var. Lilac, White Mockorange, Big Mockorange, Sweet Japanese barberry European mountain ash Purpleleaf plum Siberian pea tree Silverberry Spirea, Anthony Waterer Spirea, Vanhoutte Snowberry French tamarix Rhododendron obtusum var. amoenum Lonicera sp. Hibiscus syriacus (pink and white) Tilia americana Buddleia magnified Cornus florida Cornus florida rubra Cornus stolonifera Deutzia gracilis Betula populifolia Betula alba Betula lenta Prunus avium var. Malus var. Malus var. Malus sylvestris sp. Symphoricarpos vulgaris Forsythia intermedia Forsythia suspensa Kerria japonica Rosa hugonis Crataegus var. Ulmus americana Ulmus parvifolia Ulmus pumila Malus sylvestris sp. Hydrangea paniculata grandiflora Acer platanoides Acer palmatum rubrum Acer platanoides schwedleri Acer dasycarpum Acer saccharum Syringa var. Syringa persica alba Philadelphus coronarius grandiflora Philadelphus coronarius Berberis thunbergi Sorbus aucuparia Prunus cerasifera pissardi Caragana arborescens Elaeagnus argenta Spirea Anthony Waterer Spirea vanhouttei Symphoricarpus racemosa Tamarix gallica The Black Vine Weevil and Its Control 367 Tuliptree Liriodendron tulipifera Weigela, Red flowering Weigela Eva Rathke Weigela, Pink Weigela rosea Willow, Weeping Salix babylonica Willow, Laurel Salix pentandra Winged euonymus Euonymus alatus Rugosa rose Rosa rugosa Flowering quince Cydonia japonica Lancaster heart nut Juglans sieboldiana Sassafras, Common Sassafras variifolium The trees and shrubs are listed according to "Standard Plant Names". THE BLACK VINE WEEVIL AND ITS CONTROL J. Peter Johnson The first record of the occurrence of the black vine weevil. Brachyrhinus sulcatus Fabr., in Connecticut is that of an adult, now in the Station collection, found in New Canaan on September 19, 1910. During that year, a few other specimens also were found in New Haven and one in Litchfield. Taxus plants were injured so severely in Pomfret, in 1913, that many of them died. The injury was caused by the weevil larvae feeding upon and cutting off the roots. Occasional specimens of the insect were collected during the next few years. Since 1927 there are records of the weevils occur- ring annually, being found in nurseries and greenhouses or sent in for identification. In 1939 they were found in five nurseries. How- ever, in 1940, due to an intensive inspection of all commercial Taxus plantings, weevils were found in 19 nurseries. As the insect appears to be increasing in abundance and as it is capable of doing consid- erable damage in localized areas, a study of its habits and methods of control was inaugurated. Reports have been made by other workers on the use of lead arsenate as a spray, baits containing sodium fluosilicate or calcium arsenate for the control of the adults, and lead arsenate as a soil insecticide for the control of the larvae, as well as on the life history of this insect. Smith's (2) report on the use of lead arsenate in potting soil is about the most extensive one concerning the use of this poison as a soil insecticide for the control of the larvae. Gambrell ( 1 ) has reported on the use of various baits, sprays and soil treatments for the control of the straw- berry root weevil, Brachyrhinus ovatus (L.), a closely related spe- cies, which is often associated with the black vine weevil about the roots of Taxus. Fifteen diggings were made on May 27, 1940, in a block of Taxus cuspidata capitata, which was heavily infested, removing entire plants. There were a few spreading hemlocks and Taxus baccata repandans growing adjacent to the block of T. capitata, and one each of these plants was dug for examination. In each case the entire plant was removed and the soil excavated to include all of the root system. The results of these diggings are given in Table 44. 368 Connecticut Experiment Station Bulletin 445 Table 44. Seasonal Development, May 27, 1940. Tree l 2 3 4 5 6 7 8 9 10 n 12 13 14 15 16 17 Total Percent Larvae 9 33 34 2 8 7 4 18 2 7 1 0 7 20 3 37 47 239 60.66 Pupae 7 7 11 2 16 6 9 12 3 1 0 0 0 4 4 17 51 150 38.07 Adults1 0 0 0 0 0 0 0 1 0 0 0 0 4 0 0 0 0 5 1.27 Total 16 40 45 4 24 13 13 31 5 8 1 0 11 24 7 54 98 394 Collected during examination of debris under trees prior to digging. All of the pupae collected in these diggings were white in color and not one was in an advanced stage of development. A few of the larvae were small but most of them were fully grown or pre- pupae. The adults found were dissected in a few days and some of them contained eggs. As the spring season was cool and late, con- ditions were not conducive for early transformation from larvae to adults. The adults collected on May 27 were not fresh and clean in appearance, and as they were ready to deposit eggs, it is evident that they had hibernated successfully. The hibernation of adults has been reported from 'Pennsylvania and Oregon. Apparently only a small number are successful in passing the winter, as the above fig- ures indicate and as verified by the reports of other workers. Adult emergence from the soil was well under way by June 20. A number of observations were made during the season to note their habits. On June 28, the debris in the crotches of the trees was examined. There was a considerable amount in one tree, and upon removing about one-third of it, 20 live adults were found. Adults also were found in a similar situation in several of the other trees. Evidently the insects prefer to hide during the daytime in locations which do not remain damp and wet and will take shelter above the ground in the leaves and debris in the crotches of the trees. Most of the adults are found in the leaves and debris on the ground im- mediately around and close to the trunks. On July 5, 32 adults were found under one tree, and 22 of these were under a loose clump of soil against the base. A number were found in the cracks of the soil against the trunks. Five adults were found on September 28 in debris in two different trees and one adult in the debris under a third tree. Upon being disturbed in the daytime, the adults will play possum and remain immobile for some time. If exposed to light, they will soon try to gain shelter in debris or under loose clumps of soil. The adults feed upon the leaves of Taxus, chewing notches in the edges. Feeding has been observed between 6 and 7 feet above the ground on large, upright trees, but most of it is lower. Appar- ently a considerable amount of feeding takes place at first on the small inner branches, close to or on the trunk or main stem. If there are great numbers of adults present, feeding will be very general on all parts of the plant. The Black Vine Weevil and Its Control 369 The larvae feed upon the roots of the trees. When they are small, they eat the finer roots, and as they approach full growth attack the larger roots and oftentimes partially girdle the trees just below the crown. Heavy feeding on the finer roots causes the foliage to acquire a yellowish, unhealthy color, while severe root damage will cause leaf drop and the tree will become shabby in appearance. Severe root feeding kills the trees. A series of experiments on the control of this weevil was started during the season of 1940 to investigate the value of lead arsenate as a spray, lead arsenate as a soil insecticide, a commercial bait con- sisting of dried apple flakes and sodium fluosilicate, and bran baits containing sodium fluosilicate or calcium arsenate. Lead arsenate at the rate of 5 pounds to 100 gallons of water was used as a spray on the foliage of Taxus cuspidata and T. cuspidata capitata. As the weevils are apt to feed on any or all parts of the foliage and espe- cially that near the trunk, it is necessary to spray thoroughly to cover those portions of the plant subject to attack. Lead arsenate was used at the rate of 3 pounds to 100 square feet as a soil poison. This was applied to the surface of the soil under the plants over an area slightly larger than the diameter of the entire tree and then mixed with the upper two inches of soil. The baits were applied at the rate of about one cupful per tree, distributed evenly. Most of the trees treated were 24 to 36 inches in height, but there were a few 5 to 7 feet high. The amount of bait placed under the larger trees was increased so that the areas under the plants were ade- quately treated. The baits and lead arsenate soil treatment were applied on June 20, while the lead arsenate spray was applied on June 21, as the adults were then appearing in considerable numbers. Much rain fell and the humidity was high during the next few days, and the baits became moldy. Fresh bait was applied on June 28. Again the material became moldy and one-half of the plots received another application on July 15. The bran baits deteriorated more rapidly than the commercial bait containing the dried apple flakes. Only one application of the sprays was necessary during the season as the residue persisted throughout the summer months. The treatments were replicated four times in blocks containing from 15 to 25 trees each. Five trees were dug in each block to obtain a count of all larvae present. All the soil was removed from the roots of each plant and every digging included the entire root system. The diggings were made on September 26, 27, 30, and October 1 and 4. The results indicated that the baits containing sodium fluosilicate and the lead arsenate spray were more promising than either the bait containing calcium arsenate or the soil treatment with lead arsenate. However, all of the treatments were of merit, but further work is necessary before conclusive comparisons may be drawn. 370 Connecticut Experiment Station Bulletin 445 Literature Cited -(1) Gambrell, F. L., 1938: The Strawberry Root Weevil as a Pest of Conifers in Nursery Plantings. Jour. Econ. Ent, 31: 107-113. (2) Smith, Floyd F., 1932: Biology and Control of the Black Vine Weevil. U. S Dept. of Agr., Tech. Bui. 325. NOTES ON THE CONTROL OF MOUND-BUILDING ANTS J. Peter Johnson and R. B. Friend During the summer of 1940 many active nests of the moun- building ant, Formica exsectoides Forel., were reported in a pine plantation of the Eli Whitney Forest, in the town of Prospect. In one section of the plantation 17 mounds were situated between the pine stand and a main road and in a barway leading into the pines. They were located in areas exposed to sunlight during most of the daylight hours. The nests varied in size, the smallest being 8 inches in height and 18 inches in diameter, while the largest was 12 inches in height, 8 feet in width and 12 feet in length. The latter nest was a composite of five nests which had become contiguous. All of the mounds were very active, evidently inhabited by strong colonies. In another part of the plantation new colonies in small nests were injuring and killing young plantings of pine. The presence of these nests afforded an opportunity to check several methods of control. Eight of the mounds were treated and the results are given in Table 45. The treatments were made on August 2 when the soil tempera- ture at a depth of 3.5 inches was 72° Fahrenheit. The carbon bisul- fide in each case was applied in equal amounts in five holes in mounds 4 and 5. Each hole was closed immediately after the insecti- cide was applied. Equal amounts of methyl bromide were placed in each of five holes in mound 1, while mound 2 received the fumigant in seven holes. The top 4 inches of mound 3 was removed, the methyl bromide was poured as evenly as possible over the exposed surface, and the removed material was replaced immediately. Mound 6 was treated with pure ground derris root (containing at least 4 percent rotenone). This was broadcast by hand in a band about 12 inches wide, completely encircling the mound. Freshly cut pine boughs were placed over mounds 7 and 8 to form a blanket 12 to 18 inches in depth. Approximately six weeks after the treatments were made, the three mounds treated with varying amounts of methyl bromide were inactive and the ants dead. One mound that had been treated with carbon bisulfide was very active, while in the other the ants were dead. The large colony treated with the pure ground derris root was all but exterminated, with only a few living ants in one end of the mound and thousands of dead ants present in a band encircling the mound. Many dead ants were also found in the galleries near the exits. In both cases where the pine boughs were used to cover mounds 7 and 8, the nests were built up through the boughs so as to be exposed to the sunlight. Mound 7 had also been increased in size so as to extend beyond the periphery of the boughs. 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