PLANT BOARD May 1943 E-597 UNITED STATES DEPARTMENT 0? AGRICULTURE A GP I C ULTU RAL RESEARCH ADMINISTRATION BBREATJ OF ENTOMOLOGY AND PLANT QUARANTINE INSECTICIDAL USES OF NICOTINE AND TOBACCO A condensed Summary of the Literature, 1690-1934 By N, E, Mclndoo, Division" of Insecticide Investigations CONTENTS Page Introduction ------------------------- 2 History of insectieidal uses of tobacco and nicotine ----- - 2 I, Classes of insecticides --------------- 2 Contact insecticides --------------- 3 Fumigants- -------------------- 3 Stomach poisons- ----------------- 4 II, Repellents, or deterrents -------------- 4 III, Kinds of nicotine preparations- ----------- 4 Nicotine compounds ---------------- 4 Proprietary nicotine compounds ---------- 4 Other nicotine preparations- ----------- 5 IV, How nicotine kills insects- ------------- 5 V # Kinds of animals against which nicotine was effective 6 Insects, mites, and ticks controlled by nicotine ------- 6 I, Homoptera ---------------------- 6 Plant lice, or aphids (Aphiidae) --------- 6 Jumping plant lice (Psyllidae) ---------- 10 Leafhcppers (Cicadellidae) ------------ 11 Mealybugs, scale insects, and coccids (Coccidae) - 11 Species belonging to other families of Honoptf:ra - 12 II, Heteroptera --------------------- 12 Leaf bug$ or capsids (Miridae) ---------- 12 Lacebugs, or tingitids ( Tingitidae )- - -- -- -- 13 Chinch' bug and other lygaeids (Lygaeidae)- - - - - 13 Squash bug and other coreids (Coreidae)- ----- 13 Pentatomid bugs (Fentatcmidae) and other Heteroptera 13 III, Thysanoptera, or thrips --------------- 13 IT, Diptcra » - - 14 V, ' Hymenoptera --------------------- 14 VI, Coleoptera- --------------------- 14 VII, Lepidoptera --------------------- 14 VIII, Acarina ----------------------- 15 IX, External parasites on animals and man -------- 16 - 2 - INTRODUCTION In September 1936 the Bureau of Entomology and Plant Quarantine of the United States Department of Agriculture issued Part II of "A Bibliography of Nicotine" under the subtitle "The Insecticidal Uses of Nicotine and Tobacco," by N. E. Kclndoo, R. C. Roark, and R, L. Busbey. This Part II was issued as E-392, a mimeographed circular of 628 pages in three sections, containing 2,497 abstracts, which include the published information from 1690 to the fall cf 1934, In trying to compress the most important data contained in the original 623 pages into this brief sum- mary, the writer had a difficult task, chiefly because much of the infor- mation was fragmentary and contradictory, and the information on a given species was often widely scattered under two or three different scientific names. In the present summary the information on the most important species that had been controlled more or less successfully before 1934 by the use of nicotine is stated as briefly as possible. Nicotine has been recommended!/ against a wide range of insects which are here grouped by orders, families, and species. The unversed reader might infer from this large list of insects that nicotine is a universal insecticide and that it is the most effective means of controlling the majority of the species discussed. To the contrary, nicotine has a limited use and plays a minor part in the control of many of the species mentioned in this review. Prior to 1934 nicotine was the best remedy known for certain species, but' more recently other insecticides, particularly oil sprays and rotenone, have taken that place. To emphasize the importance of the species mentioned, the present circular includes the geographic distri- bution of many of them, the countries being arranged in the chronological, order of the references. HIS TOE Y OF IFSECTICIDAL USES OF TOBACCO AND NICOTINE I. CLASSES OF INSECTICIDES Insecticides are generally divided into three classes, based on the way they are applied to the insects. The contact insectici des com- prise both liquids and solids. In the literature on nicotine the liquids are described as washes, tobacco water, infusions, decoctions, tobacco juice, extracts, and. dips; and the solids, as powders and dusts. The fumigants are called smokes, fumes, or vapors, and are produced by burning or heating tobacco in solid or liquid form, Vihen the liquids "TJ This should be understood throughout this summary to mean that the writers of the various articles listed in the bibliography recommended the specified treatments. No appraisement by the Department of Agriculture is implied in citing the various preparations mentioned or statements regarding them. - 3 - and solids are applied so as to be taken into the stomach they are called stfmach poiso ns. Tobacco and nicotine are used chiefly as contact insecti- cTcles and fumigants, and very little as stomach poisons. Contact Insecticides Tobacco was first utilized ir. 1690 as an insecticide, a wash having been applied to pear trees in France to control the poar lacebug. Tobacco water and tobacco powder were recommended in 1763 as a remedy for plant lice in France, In acme cases tobacco dust .was used successfully in 1773 against apliids and the red spider in England, In 1800 tobacco was in common use as an insecticide in England, Tobacco dust was blown from a powder puff, such as hairdressers used, upon aphid- infested trees, or Scotch snuff was merely dusted upon the insects. Infested leaves were also dipped in a strong tobacco infusion. Tobacco was first used as an insecticide in America at Albany, N, Y,, in 1814, tobacco water having been applied against sucking insects. In the same year a force pump was employed to squirt a decoction upon caterpillars and a leaf roller in England. Tobacco juice was recom- mended In 1829 for the woolly aphid in England, Tobacco extract was first mentioned in 1859, nut in the 1880' s and 1890' s it was commonly referred to in the literature. The word "dip" was first mentioned in 1896, and later it was frequently used, Fumigants In 1773 tobacco was put in an iron pipe which was heated and the smoke from it was blown onto infested plants by the use of a bellows. Another type of' fumigating bellows was used and described in the same year. In 1800 a pair of bellows was used to force smoke under a tent which had been put over a nut tree infested with aphids. In 1828 a tent on wheels to go over a grapevine trellis was recommended in America, and in 1839 growers were advised to burn paper saturated with tobacco extract under a tent stretched over poach and nectarine trees to kill aphids. In 1851 a fumi gator which burned tobacco and ejected the smoko was invented. In 1879 a specially constructed hood was invented and used in England, This was put over rose bushes infested with aphids, and tobacco smoke was con- ducted by pipes into the hood. In 1902 the Geneva fumigator was employed to fumigate aphids. Turning to the use of tobacco indoors, it was becoming the custom to use tobacco smoke in greenhouses as early as 1825, and in 1877 mention is found of putting tobacco juice on a hot metal plate in order to make a dense smoke in a box containing aphid- infested plants. In 1884 tobacco extract was put on the heating pipes in a greenhouse, and in 1895 red-hot bars and in 1897 hot bricks were used to vaporize the extract. The method of dropping the liquid on hot metal was the forerunner of the present aerosol method. The most common method of fumigating with tobacco, however, was to evo.porate the tobacco extracts in shallow vessels over charcoal, kerosene, or alcohol stoves. - 4 - Stomach Poisons y v r' ! ', ' >' , ~ J" .< ' Not until recently did writers discuss how nicotine affects insects, and consequently their papers do not mention nicotine or tobacco as stomach poisons. In 1911 it was observed that the ingestion of leaves treated with nicotine caused characteristic convulsions of flea beetle larvae, which died shortly afterward. Larvae of vine moths and beetles were partially co3itrolled in 1913 as a result of their eating nicotine-treated leaves. Nicotine was fed to honeybees in 1916, and the symptoms of poisoning were carefully studied for the first time. It was shox.n in 1932 that nicotine compounds acted slowly as stomach poisons against the walnut husk fly (R hago letis suavi s ( O.S . ) ) . II. REPELLENTS, OR DETERRENTS Repellents are not really insecticides, but since they repel insects or deter them from doing damage, their effects and those of insecticides are. usually discussed together. Tobacco, because of its strong, penetrating odor, is considered an insect repellent, and as such was first used in 1734. III. KINDS OF NICOTINE PREPARATIONS In addition to the previously mentioned tobacco and nicotine prepara- tions there are about 80 more, and the history of nicotine as an insecticide after 1885 pertains mostly to them. In regard to most of them it will not be possible to give the exact dates in which they were first prepared and used, but the first dates to appear in the literature are those that should be no bed here. Nicotine Compounds From 1900 to 1934, 15 nicotine compounds or salts were prepared and used, and since 1934 several others have been added to the list, although these are not to be considered here. The 15, with the first dates which occur in the abstracts or could be found in notes and the original literature, are as follows: Nicotine sulfate (1900); acetate, lactate, nitrate, and trichloroacetatc (1913); resinate (1917); oleate, palmitate, and stearate (1918); tartrate (1919); salicylate (1927); caseinate (1929); tannate (1930); alginate (1931); and bentonite (1934). Proprietary Nicotine Preparations The list of proprietary preparations contains 63 trade names, both domestic and foreign, most of which were patented, and many of which seem to have been short-lived. These names did not represent 63 different preparations because one preparation occasionally had two names or one name v/as later substituted for another. Gold leaf Tobacco Extract (1885), which was apparently the first of the proprietary preparations, was later called Black Leaf Tobacco Extract. From 1885 to 1900, 12 other preparations, including some important dips, were put on the market. In 1892 the first standardized nicotine extract, called Rose Leaf, was placed on the market. - 5 - It contained slightly less than 3 percent of nicotine and for many years was more efficient and more widely us«*d than any other form of nicotine. During the next decade 11 more preparations were introduced, half of which proved to be excellent insecticides. A few of these are still being used| In 1908 a patent was granted covering a method of producing a con- centrated solution of nicotine sulfate containing as much as 40 percent of nicotine. This sulfate was first called Nico-Sul, but in 1910 it was placed on the market under the name of Black Leaf 40, From 1911 to 1920 about 22 additional proprietary insecticides were introduced, three-fourths of which were foreign, A new type of nicotine-bearing dustj called Nicodust, was first placed on the market in 1920, From 1921 to 1934, 16 more trade names were added to the list. Those most frequently found in the literature include Nico-Fumc Fumigating Powder (1922), Vapona (1933), Black Leaf 50, ar.d Black Leaf 155 (1934). Other Nicotine" Preparations In America dependence has been largely upon the proprietary prepara- tions, but in Europe, particularly in France and Germany, the proprietary products seem not to have been widely used, chiefly because the preparation of nicotine insecticides was controlled by the government. The State factories of France in 1909 prepared ordinary tobacco juice and titrated juice for the agriculturists. The nicotine content of the former depended on its density v/hich, since 1882, was determined by a hydrometer in degrees Baumel The titrated juice, containing sulfates of nicotine and sodium and organic salts, rath a nicotine content of 10 percent, was sold as titrated nicotine. In 1924 the French Government issued nicotine in three forms — ordinary juice, an extract containing nicotine sulfate, and condensed juice (a mixture of the other two), IV. HOW NICOTINE KILLS INSECTS A little casual information on the physiological effect of nicotine is to be found in numerous papers from 1895 to 1934, but only a few studies were originally planned to determine how nicotine kills insects. A few. other papers give additional information which is probably correct but not supported by experiments. It was the fundamental information on this point that led to the preparation and use of nicotine dust. The symptoms of nicotine poisoning in the experiments with bees in 1916 were, divided into three stages. First, bees that had eaten nicotine soon became abnormal in behavior, and the legs and wings were partly paralyzed. Second, the paralysis progressed from partial. to complete, the hind legs and hind wings usually being the first to be completely paralyzed, then followed the middle legs and front wings, and, finally the front legs. Third, the bees wore apparently dead except for slight movements of the head appen- dages, legs, and abdomen. Regardless of how nicotine is applied, it seems to kill by motor paralysis; that is, it first affects the nerve centers that control muscular movement. Its action on the motor centers causes complete paralysis, which is supposed to be brought about by absorption of the nitrogen atom of the poison by the nitrogen-fat compounds that make up the nerve tissue, with the result that further absorption of oxygen by the cells is stopped and the insect is killed. Since 1916 the word "paralysis" has been repeatedly used in connection with the effects of various insecticides, but incorrectly, perhaps in most instances, because there are very few insccticidal nerve poisons. - 6 - Until recently it -was thought that nicotine spray solutions and dusts passed into the spiraeles and caused death by suffocation. It is now known that spray solutions, without soap or other spreader, do not pass through the spiracles into the tracheae. If they contain a spreader, however, they do pass into the tracheae, although their presence inside the insects does not necessarily cause death. Only nicotine vapor from spray solutions, exhalations from nicotine dust, tobacco powder, or from dried films of spray solutions, and fumes from "burning tobacco pass far into the tracheao and are widely distributed to all the tissues, particularly to the nerve tissue, which is the first to be affected fatally. V. KINDS OF ANmALS AGAINST VfHICH NICOTINE YlkS EFFECTIVE According to the literature prior to 1934, nicotine was effective and had beer, recommended against only those organisms having soft bodies and others of minute sise, such as mites, thrips, aphids, psyllids, leaf- hoppers, crawling scale inseets, capsids, laeebugs, lice on poultry, midges, mushroom flies, sawflies, and grapevine moths. These and a few mare are discussed somewhat in detail in the following pages, being arranged by orders, families, a»d species. INSECTS, KITES, AKB TICKS CONTROLLED BY NICOTINE I . HW'OJTSEA Plant Lice, or Aphids (Aphiidae) TToolly apple aphid .--The application of nicotine has usually effected a satisfactory control of the woolly apple aphid ( Eriosoma lanigerum (Hausm. )) since 1814, but as this species is covered with a woolly or waxy covering a spreader is always required ir. the wash or spray solution. This aphid'becurs in two forms— the aerial form living on the limbs and leaves, and the root form on the roots. It appears to be universally distributed with the apple tree, for according to the literature it has been treated in 16 countries. In Europe up to the 1890* s the wash or spray mixture consisted of tobacco juice, water, and soap, and sometLmos sulfur or lime was added. After 1898 concentrated tobacco juice, whose nicotine content was determined . by the hydrometer or by titration, was incorporated with water and soap, and it was common in Europe to add alcohol, sodium or potassium carbonate, or even oil. After 1910 it became common practice to use Black Leaf (3 per- cent nicotine) and Black Leaf 40 with soap or an oil omulsion in the following countries (chronological arrangement ) : United States, New Zealand, Tasmania, Australia, Korea, and Canada, Since 1884 tobacco has been used as a remedy for aphids on the roots. The method is to remove the earth around the base of the tree and over the roots, then to put an abundant supply of v/aste tobacco or tobacco dust against the wood bearing the aphids, and finally to cover the tobacco and roots with earth. The insects in time should be killed or driven away, but this method is often unsuccessful. Other apple aphids, — Ir. all there are sever. :r eight species : f apple aphids* "but as their treatments do not differ vridely, only two other species 7ri.ll be discussed here. Since 1867 the apple aphid ( Aphis pcmi Deg. ) has been controlled on apple trees frith nicotine in Russia, the United States, Canada, England, Germany, Kor^ay, and Ireland, In the earlier years, ?.:se Leaf, Black Leaf, Aphis Punk, Nikoteen, Niccticide (40-percent nicotine), tctaccc dust, and hcne-ra.de tobacco extracts vrere used in sprays or as furd.- gants for this aphid. Since 1915, particularly in the United States and Canada, Black Leaf 40 has been used as a delayed-dcraant spray, "which is generally incorporated "with lir.e-sulfur but sometimes trith soap, an oil emulsion, Penotrol, caustic soda, or potassium ole&te. Z'r.e rosy apple aphid ( Anuraphis rcseus 3aker) appears to have been treated only in the United States and Canada. Ihe best spray used against it "B&s a combination in the proportion of 100 gallons of rrinter— strength line-sulfur and 5/4 pint of 40-percent nicotine. Ihe best tine for treat- ment Tsas during the delayed- dormant period just tdien the buds "v^re beginning to shot; green, ZTicctine has been used effectively against ti-.is aphii since 1902, Peach aphids, — Ihere seem to be four or five species of aphids that infest peach tress. Ihe black peach aphid ( Anuraphis persicae-niger (Sr.dth)) has been controlled with nicotine since _:~c in 7rai-.ee, and for =. snorter time in the United States, Australia, I only, and South Africa, 3efore 1910, tobacco decoction, tobacco dust, Black Leo.f, and Black Leaf lip - ere used. After 1910 it :as corv.cn to use Black Leaf 40, sheep dips, and ether standardised tobacco extracts in kerosene or petrol eum evulsion, soap solution, or lime- sulfur. Nursery trees to be transplanted -vrere fumigated or dipped in a nicotine spray mixture, Aphids on the roots of peach trees ■were controlled by putting tobaoco poTnier on the roots as already described for the vrcolly apple aphid. The green peach aphid (Ityzus persicae (Sulo.V infests vany plants besides the peach Tree. According _ o the literature, nicotine controlled it on peach"/ j potato, tobacco, beet, donate, pepper, spinach, eggplant, cauliflower, and other vegetables. Nicotine "was first used against it in ; 1903, and it vas treated in: the united States, Hat.aii, Australia, Sown Africa, Tasmania, France, Italy, England, and India, The most common spray ccr.sds^ed cf 40-percent nicotine as the sulfate trith soap, but in l?2c car- bolated tobacco extract uns used in Italy and tobacco decoction frith soap in India as late as 1952, Sprouting seed potatoes vere fur.' gated v.tth nicotine and tobacco dust, and this species vas most easily controlled on vegetables by usint 3 rercont nicotine dust. In lists of plants the order is governed by the number of references t»ere cited from the literature. - 8 - Spi rea aphi d.- -This species, Aphis spiraecola Patch, also called the green cirrus aphid", is important economically because it infests citrus trees in Florida, It has been controlled with nicotine since 1924, Sprays con- taining 40^-percent nicotine sulfate and soap or sodium oleate were found successful against it, and a 3-percent nicotine dust was particularly recom- mended. Black cherry aphid. --Tobacco and nicotine have been" used as a control for the "black cherry aphid (Myzus ceras i (F, )) on cherry trees since 187'2, In Germany it was treated with a tobacco decoction and soap. In the United States the following were used: Black Leaf, Black Leaf 40, or other 40- percent nicotine with or without soap, lime-sulfur, or a miscible oil; a 50- pcrcont nicotine sulfate plus potassium oleatej Nicodust; and lime-nicotine dust. In Russia it was fumigated with tobacco dust or sprayed with a car- bolated tobacco emulsion. In Canada it was sprayed with 40-percent nicotine sulfate and limo-sulfur. In France it was treated with a nicotine-soap spray heated to 212° F. Other fruit aphids » — Aocordin g to the literature reviewed, many other species of fruit aphids have been successfully controlled with nicotine. These include 1 species on almond, 1 on banana, 2 on citrus, 6 on currant and gooseberry, 1 on fig, 2 or more on grape, 1 on loganberry, 6 on nuts, 1 on. pear, 2 or 3 on plum, 3 on prune, 1 on raspberry, and 4 on strawberry. Bean aphid.— During the past decade the "bean aphid ( Aphis rumicis L. ) has become the standard insect for testing contact insecticides, as it is easily reared and is more easily kill eel than most aphids. Since 1915 it has been readily controlled with weak concentrations of nicotine. It infests a wide variety of plants, but the literature on nicotine mention's only the following: Beans, beets, tomatoes, artichokes, sorrels, chrysanthemums, Euonymus, and nasturtiums. This species has been treated in the United States, Canada, Russia, Denmark, Algiers, Italy, Czechoslovakia, England, Franco, and Cyprus. Against it the following have been used: Nicotine (40- and 50- percent); nicotine sulfate (25-, 30-, and 40-percent); nicotine resinate; nicotine ' oleate; nicotine with sodium oleate, potassium stearate, calcium caseinate, Penetrol, or soap; sulfur impregnated with 2 percent of nicotine sulfate; 5-percent Nicodust; 3-percent nicotine sulfate dust used at the rate of 40 pounds per acre; and almost perfect control on lima beans was obtained by one treatment with a 1,6-percent nicotine dust applied with a self-mixing power duster equipped with a canvas drag which covered the rows for 10 feet behind the duster. Cabbage and turnip aphids,— The cabbage aphid ( Brevicoryne brassica e (L.)) has boon controlled with nicotine since 1908 and has been treated in Australia, the United States, Hawaii, Italy, and Canada, Tobacco tea plus soap, carbolated tobacco extract plus sodium carbonate, Black Leaf, Nico- Fume, Black Leaf 40 with or without soap or miscible oil, tobacco dust, and nicotine dust have been used against it. The turnip aphid ( Hhopalosiphum pse udobrassicae (Davis)), also some- times called the false cabbage aphid, has been controlled with nicotine in the United States since 1915, 40-perccnt nicotine sulfate sprays and nico- tine dusts having been the most popular controls up to 1934, although more - 9 - recently rotenone has become the favored material. Pot ato aphid s . — There are only two aphids -that seriously attack potato plants. One of these, the green peach aphid, has been discussed. The other is the potato aphid ( Macrosiphum sol anif ol ii (Ashm. )), which, however, infests plants other than the potato. This species has been controlled \/ith nicotine since 1915, having been mentioned as so treated only in the United States and Canada, The best remedies up to 1934 were a spray consisting of nicotine sulfate and soap, 2- and 3-percent nicotine dusts, and a dust composed of tobacco powder and hydrated lime. Two other aphids infest potatoes, but they are unimportant, for each was mentioned only three times. The remedy for them was the same as given above. Pea aphid . —The pea aphid (Macrosiphum pisi (Kalt,)) has been treated in Canada and the United States with tobacco preparations since 1909, but not always successfully. Nicotine sulfate sprays and dusts were often recommended, and the most economical remedy seemed to "be a 3-percent nicotine dust applied to rows of peas with a tractor duster having a canvas trailer. Aph ids on oth er vegetables, — Ten other aphids on vegetables have been briefly discussed in the literature. Tobacco extracts controlled all of them — 3 species on sugar beet and lettuce in Europe, 2 each on tomatoes and celery in the United States, 1 each on beans and artichokes in the United States, and 1 on parsnips in Canada, Hop aphid , — This species, Phorodon humuli (Schr,), had been easily controlled since 1904 with nicotine because it is perhaps the most easily killed of all aphids. It was treated in the United States, Bohemia, Germany, Canada, and England, Against it were used tobacco decoctions, Black Leaf,' Black Leaf Dip, nicotine sulfate plus soap or flour paste, 5- percent Ivicodust, and 1-percent nicotine dust. The last seems to be the most frequently used in hop yards. A p ple grain aph id. — This insect, Rh opalosiphun prun ifo liae (Fitch), has been treated with nicotine in Canada and the United States since 1914, The best remedy was nicotine sulfate plus lime sulfur. Melon or cotton aphid,— This species, A phis gossypii Glov., attacks a wide variety of plants, but the abstracts mention only cotton, melons, cucumbers, gourds, and hibiscus, the first two being attacked the most seriously. It is widely distributed, and has been treated with nicotine, first in the United States, then later in Belgium, Nyasaland, Mexico, Chile, Canada, French West Africa, Bermuda, Peru, Russia, and Brazil. In 1901 tobacco decoction, Rose Leaf, Skabcure Dip, and Nikoteen Punk v/ere used against .it, but since then Block Leaf, nicotine sulfate solution, free nicotines, and various tobacco-fumigating preparations have been used. Nicotine dusts were first tried against it in 1921 and since then they have gradually becomo more popular. In 1926 a 2-percent dust, applied at the rate of 35 to 40 pounds per acre on melons, was recommended, A dust com- posed of 94 parts of calcium arsenate and 6 parts of nicotine sulfate solu- tion (40-percent nicotine), applied at the rate of 3 or 9 pounds per acre of cotton, was recommended against the boll weevil (Anthonomus grandis Boh.) and this aphid. r - 10- Aphids on conifers .-- In the cited literature six species are dis- cussed. All seen to "be economically important and they were successfully controlled on spruce, fir, and pine trees with tobacco extract, nicotine (98-percent), or nicotine sulfate solution, each with the addition of soap or an oil; or with nicotine dust. The eastern spruce gall aphid ( Chermes abieti s L.) was treated in Poland and the United States, C_, cooleyi Gill, in the United States, C, picea e Ratz, in Germany and Switzerland, Pineus pini (Macq,) in Norway and the British Isles, the pine bark aphid (P, strobi (Htig,)) in the United States, and P, similis (Gill,) in Nova "Scotia and the United States, Aphids on other trees .— 'Nine other aphids were controlled with nico- tine but were discussed only briefly. These are one species each on balsam, boxelder, Carolina poplar, willow, and tuliptree, and tw» species each on elms and other shade trees. The species on the willow was treated in France and all the others in the United States, Ro se aphids , — There are at least two species of aphids which infest rose busTTes, They are among the aphids most resistant to nicotine but can be readily controlled by applying heavy doses. The most common, the rose aphid ( Llacrosiphum rosae (L,)), has been controlled with nicotine since 1307 and was treated in Belgium, Germany, the United States, France, and Ireland, Sprays consisting of nicotine sulfate solution and soap and 5- percent Nicodust were recommended as remedies. In greenhouses, fumigation, spraying, and dusting vdth nicotine preparations were practiced. The small green rose aphid ( Capitophorus rosarum (Kalt.)) was treated only in France and the United States, Chrysanthemum aph id. — This species, Macrosiphoniella sanborni (Gill,), has been controlled with nicotine since 1911 and was treated in Hawaii and the continental United States, Black Leaf 40 plus soap was the usual remedy. Aphid s on other flower s ,— Four aphid.s infesting other flowers were easily controlled with nicotine. They were on the leaves and bulbs of tulip and iris and on violets in Europe, and on gladiolus corms and geraniums in the United States, Jumping Plant Lice (Psyllidae) Apple auoker. — The apple sucker ( Psylla mali (Schmb.)) has been con- trolled with nicotine since 1913, It was treated in Germany, Russia, England, Norway, Ireland, Denmark, Nova Scotia, Sweden, Czechosolovakia, Finland, and Switzerland, The common method was to spray vdth nicotine or tobacco extract plus soap. In Russia it was successfully controlled by fumigating orchards vdth tobacco dust mixed with straw. Pear psylla. — This psyllid, Psyll a pyricola Foerst,, was first treated in 1842, in England on pear trees, vdth a tobacco infusion, but the practical control of it seems to date from 1912, when Black Leaf 40 and soap were used. It has been treated in England, the United States, Canada, Germany, Sweden, Czechoslovakia, and Italy vdth niootine sulfate solu- tion vdth soap or line-sulfur. Various nicotine dusts have also been recom- mended against it, and a 2-percent dust seems to have been the most economical. - 11 - Seven other psyllids have been controlled with nicotine, but these species are not economically important. Leaf hoppers (Cioadellidae) Pota to le af hoppe r, — This insect, Emp oasca fabae (Harr.), is also known as the apple leaf hopper or bean leaf hopper and as the potato jassid. It has been treated with nicotine sinco 1908 in the United States and Canada, In most instances nicotine sulfate as either spray or dust v/as recommended as a satisfactory control, but in a few instances it was inefficient or was not so good as bordeaux mixture, which acted as a repellent. Grap e leafhoppers »— Those leafhoppers, Erythroneura comes (Say) and related forms, woro' treated with nicotine in the United States and Canada, In 1828 tobacco juice was only partially effective and a tobacco fumiga- tion tent on wheels to go over the grapevine trellis v/as recommended as effective, but "was soon discarded as impracticable in vineyards, A more serious attempt to control these leafhoppers was begun in 1910. The nymphs are easily killed with nicotine, but in order to control the adults the dosages must be very strong. Black Leaf 40 with scap, bordeaux mixture, or other substances added to the sprays were used. Nicotine dusts, if unusually strong (7,5 or 10 percent), were generally efficient. Rose leafhopper.- — This jassid, Typhi ocyba rosae (L. ), v/as treated in the T^TFedY S'-lJa : Ee~s7~"Sweden, Switzerland, Canada, and Czechoslovakia, It v/as controlled by using nicotine with coap, Black Leaf 40, and nicotine dust. Other leafhoppers,— About two dozen 'other leafhoppers have been oontrolled with nicotine. The most important of these appears to have been the v.hibe apple leafhoppor (Typ hi ocyba pomaria McAtee), Mealybugs, Scale Insects, and Coccids (Coccidae) Citrus mealybug,— This coccid, Pseudococcu s citri (Risso), has been treated with nicotine ' s ince 1911 in the United States, Uganda, Grenada, Russia, Bermuda, and the Philippine Islands, Tobacco dust was inefficient and tobacco extract gave indifferent results. Black Leaf 40 and nicotine were usually effective, but other control methods were available. San Jos e scale. --This scale insect, Aspidiotus perniciosus Comst,, has been treated with nicotine since 1901 induce n's land, the United States, India, and Hungary, Nicotine with soap, lime-sujfur, or an oil was usually effective against the immature scales. Oys ter s hell jscale, — Nicotine sulfate with soap or lime-sulfur has been used succes'sfiTlly"" since 1916 against the young of the oystershell scale (Lepl dosaphes ulmi (L.)) in the United States and Canada Other coccids, — About 42 other species of coccids were tested with nicotine, and it was found effective against all but 4, The best spray or dipping solution was kerosene emulsion containing nicotine. * 12- Species Belonging to Other Families of Homoptera "Whiteflies .--Seven species of Aleyrodidae were tested with nicotine, which, was nearly always inefficient. Other species .— Thirteen species of the Cicadidae, Fulgoridae, Cercopidae, and Menihracidee were treated vdth nicotine. It was efficient against a cicada, 4 fulgorids, 3 froghoppers, and 1 treehopper, II. HETEF.OPTERA Leaf Bugs, or Capsids (Miridae) Apple redbug , — Nicotine has been used against Lygidea mend ax Reut. since 1911, when sprays containing Black Leaf (1 part to 65), Nico-Fume (l to 700 ), and Black Leaf 40 (l to 816) were found effective. This species, as well as other capsids, is difficult to control, and nicotine is efficient only against the nymphs. Sprays containing 40-percent nicotine sulfate (l to 800 ) and soap or lime- sulfur usually gave good control. A 4.7-percent nicotine dust was also said to have been efficient. This important economic species was treated in New York, Ohio, Connecticut, Pennsylvania, and Nova Scotia. Tarnish ed plant bugs . — These species, Lyg us oblineatus (Say) and L. prat en s is (L, ), have been treated with nicotine since 1915 in Canada, the United States, Germany, and England. Nicotine in various forms was recommended, hut in the United States there was no complete control, although a 5-percent nicotine dust and a nicotine sulfate spray (l to 200 ) plus soap were used. Dark redbug.— Since 1911 H eterooordyl us ma 1 in us Reut. has been treated wi€h nicotine in New York and Pennsylvania, busts were as good as sprays. Fea r plant bug ,— This insect, Lygus co mmunis Knight, has also been called the green apple bug and false tarnished plant bug. It infests apple and pear trees in Mew York, Nova Scotia, and Ontario, Nicotine has been used against it since 1916, a 5-percent dust (2 percent aotual nicotine) having been better than nicotine sprays, , Apple caps id bug . — Since 1916 PI esiocor i:: rug icollis (Fall.) has been controlled with nicotine (usually 98 percent) plus soap in England, Denmark, and Holland* Othe r caps ids .— According to the literature nicotine was used on a small scale against 32 other capsids. Eight of these species belong to the genus Lyj-rus, one of which, Lygus pabulinus (L.), seems to be an important economic species, for it was treated with nicotine in Ireland, Denmark, England, and Germany. - 13 - Lacebugs, or Tingitids (Tingitidae) Pear lacebug, — The bug Stephajiitis Pyri ( F, ) v/as the first insect to be treated with nicotine, the dete ancfpTace being 1690 in France, It is a serious pest of pear trees ir. Europe. In France tobacco fumes and nicotine sprays were used;