E-665 thiited States Department of A^lculturi Aiprieultural Beteareh Adninittratlon Bureau of fiitonolofir and Plant Qparantlne I THS PLANT AS A SOTJBCS 07 INSBCTICIDX8 \ A BX7IXV 07 tES LITZRATDES i , Igr V* X* Mclndoo, Dlvltlon of Inteetlclde Inreitig^tlont \ Interest in the use of the eastor-hean plant (Blclnus conmunis L.) for the control of insects has heen stiorolated in the past few years popular articles declaring that crops could he protected hy means of border or strip plantings of this plant, and also the recent derelopnent of a hew spray material extracted from it# leares. In order to leam the hasis for these reports and to determine whether it would he worth %diile to do more work on the castor-hean plant as a source of insecticides, a search of the literature was nutde* The information obtained is briefly re-riewed in the following notes« Insects Reputed to Be AffeetM. grasshoppers, —In New South Vales it was suggested that castor- beans be sovn in small patches near the breeding ground of grass- hoppers for the purpose of destroying this pest. This plant was re- ported to be fatal to grasshoppers* In fact, it was said that "the locusts will fairly bury up the young plants, so thidcly will the dead accumulate underneath th«B«*— Anonymous (2)* In 7ictoria, Australia, the planting of Ricinus communis on the borders of fields was considered an efficacious means of controlling locusts.— Haras (36. p. 109)* Swarms of immature grasshoppers , Sas8ion for the cas- tor-bean plant that they hardly - touched other plants on either side of the barrier. Away from the castor-bean barrier the grain losses from birds and hoppers ran up to 95 percent. Along the barrier the grain loss ranged from 33 percent to none at all. The barrier was of two varieties of castor«bean, cambod^nsis being much more effective than the larger variety, zanzibarensis. yfhea 10 castor-bean plants were transplanted to a cornfield swaning with grasshoppers, the hoppers left the corn to eat the transplants cosqpletely, and then died. In a park dead hoppers were found beneath ornamental castor-bean plantings. In a test 19 hoppers were ca^d with some castor^bean foliage, which killed l6 of them in US hours.— Bear (10). The story of Or. Christensen* s 17-aere experimental farm near Atchison, Kans., was again told in 19^2. Fifteen aore-s of this farm were devoted to the growing of weeds and the other 2 acres to grain sorghums, castor-bean plants, and other things not planted by plains farmers.— Berth (11 , pp. 176-181). The evidence available does not indicate that castor-bean plants have any great importance in grasshopper control, but It is Insufficient to warrant a statement that no variety of them has any value for that purpose. Certainly, the extravagant claim that they seem certain or even likely to solve our grasshopper- control problem is not Justified.— Bare G-rowing castor-bean plants to eliminate grasshopper damage to crops does not work, despite some publicity to the contrary. The con- clusion that these plants are of no value in grasshopper control came as a result of an experiment conducted over a period of 3 months which involved at least 300 grasshoppers and severed varieties of eaftov- beans. — [Drake] (19)> Tests have proved that castor-bean foliage is not polsonotis to grasshoppers or other insects.— Oklahoma Agricultural Experiment Sta- tion (^, p. 212). In order to settle the controversy Invoked by Dr. Chrlstensen* s observations, carefully planned experiments were conducted in Kansas. Tests with grasshoppers caged over castor-bean plants were first con- ducted, in both the laboratory and the field. The four varieties used - 3 - were zanzfbarenels, cambodgenslB, amd a comm\mity selec- tion cadled "Wagner,' The ca^e tests indicated that grasshoppers live fairly well— some as long as 66 days — on sua exclusive diet of castor-hean foliage and petioles. Observations on feeding showed that grasshoppers did not relish any part of the castor-hean pletnta. Some individuals refused to eat the foliage and grew weaker from lack of food, >diile others, either from weakness or aild poisoning, appeared to he partly paralyzed, in which condition th«y often survived as long as 3 days. The supposition that castor-beans have an attractive value may have arisen from seeing grasshoppers and other insects ali^t on these plants, which grow tall, almost treelike, and offer perches, shade, and a certain amount of protection from enemies. Food attractive- ness is not necessarily involved when insects perch on the stems or leaves. It was concluded that "castor-beans cannot be used as a trap crop because th^ are not more attractive to grasshoppers and other common pests than the usual crop food plant. While castor-beans are apparently objectionable to grasshoppers, crops cannot be adequately protected by border or strip plantings because of the easy mobility of the hoppers. No evidence of any value of castor-beans for poisoning, repelling, or trapping grasKhoppere or any other crop insect pest was ob- served during the season of 1932. No real protection was observed in fara plantings and none was reported by farmers,* A long list of insects found on castor-bean plants in Kansas was also published. — Smith , The erroneous idea has been widely held that grasshoppers may be poisoned by planting castor-beans around and through the crops to be protected, Ixperiments conducted by the United States Bureeu of Ento- mology and Plant CJuarantine and several State experiment stations in- dicate that this practice has no value. When given no food other than castor-bean foliage, grasshoppers will eat sparingly of it and will die in about the same time as when given no food. When they are given a choice, other plants are preferred. Young grasshoppers have been reared to the winged stage in cages containing growing castor-bean and oat plants. They thrived on the oats, but did no more than nibble on the castor-beans although they grew to maturity on them,— P-orker (39) • According to a compilation on the "Insects of the Castor-Bean," this plant has attracted attention as an alleged killing agent for insects, particularly grasshoppers and the Japanese beetle, but the literature contains only a few records of insects being poisoned by feeding on the plant,— l^ers (35) . Tests in Iowa gave no evidence that grasshoppers are attracted to castor-bean plants. Common crop plants were selected in prefer- ence to the eight varieties of Riclnus tested in cages. Neither was there any evidence of a repellent effect, because the grasshoppers used in these tests often rested on the plants, and under field condi- tions grasshoppers have been observed to spend the night resting on castor-bean plants and then to move in the morning to other plants to - H - feed. Since graeshoppere vere able to surrtTe longer on an ezclaelye diet of castor-'bean plants than without food, the poisonous principle in the plants had very little, if any, effect on the insects. There- fore, these plants could not be regarded as having any direct value in the control of grasshoppers or in preventing them from injuring crops,— Spain (^5) • It was thought that the conflicting reports on the toxicity of castor-bean foliage to grasshoppers might be due to differences ex- hibited by different varieties of the plant. The following 11 var- ieties of Ricimie coamunis were tested on nyxophs and adults of Melan- oplus differential is (Thos.): africanus. bourboniensis. Brazi?.ian, cambodgensis, coBuaunls. Duchess of Idinbur^, £lbsoni, panomitanus. Eed Spire, sanguineus, and Zanzibar ensie. Individual nyinphs were caged on the leaves and the amount eaten was noted daily. With zanzibarensie 8 days and with Red Spire 37 days were required to obtain 50 percent kill. The other varieties showed intermediate periods. Soiie of the nyophs that stirvived transformed to adults on the foliage. The amount of foliage eaten by the nymphs and adults that died was barely suffi- cient to sustain life, so that the factor of starvation could not be eliminated. There can be no doubt that castor-bean foliage contains a toxin, for a number of nyaiphs that fed on the foliage were paralyzed in the legs, althoo.^ some so affected continued to live for days. The foliage of no variety tested, however, was found to be sufficiently toxic to be satisfactory as a practical insecticide. — ^Harteell and Wilcoxon (26, p, 138), Beetles,— Twenty- four acres of tea bushes were interpleuated with castor-bean plants to test the value of the latter as trap plants to help control the tee shot-hole borer (jtyleborue fornicatus Eichh,) in Ceylon, This method of controlling these beetles was apparently effective, provided the infested castor-bean branches were systemat- ically remdved.— Jepson (30) , Castor-bean plants gro%m near sugarcane in Puerto Rico will attract many weevils,— Wolcott (^2) . Pests of the avocado in Puerto Rico include the weevil Diaprepes abbreviatus (L.), which attacks the leaves and is only repelled by arsenical iprajt, but may be attracted by a trap crop of castor-bean plants. — Gonzlb.e8 R£os and Mayoral Reinat (22). In northern Caucaeas larvae of Pedinus feme rails (1.) that were fed on seedlings of castor-beans survived, — [Stepantzev] (J^S). Castor-bean plants grown near sugar beets in Rumania were attacked by (Cleonue) Bothynoderee ponctiventris (Germ.). All the beetles feeding upon the cotyledenous leaves died, 10 to 15 being found dead daily around each plant. — Orinberg ( 2U) • - 5 - A large seod establishment at Bristol, Pa«, announced a new and natural control for the Japanese beetle. T/fhen castor-beans were plant- ed a short distance from the flowers, the beetles left the flowers and swarraed over to the castor-beans, eating the large leaves. These plants caused slow but sure death, and great piles of beetles were swept up from under them each morning. Ten cents worth of castor- bean seed planted a short distance from a gsurden was considered to help solve the Japanese beetle problem.—Landreth (31, 32) • Owing to the publicity given to this discovery, a series of tests was conducted by the Bureau of Entomology and Plant Quarantine at its Japanese beetle laboratoxy in 1932 to determine the attrao*!- tiveness and toxicity of the castor-bean plant to the Japanese beetle. Tests were made on 6 varieties of this plant— 'cambodgensis, panor- mitanus, gibsoni. Red Spire, sanguineus, and zanzibarens is— grown at lioorestoTin, N« J. The beetles fed on the foliage of sanguineus and Zanzibar ensis, but the other varieties were practically immune. Large numbers of dead beetles were foxind under these plants, but they could also be found under other plcmts heavily infested by this in- sect. Under certain field conditions, however, castor-bean foliage appeared to be toxic to the beetles. In cage tests they fed on the foliage to a limited extent. However, no tested variety of castor- bean ¥ras sufficiently attractive to indue© the beetles to leave fa- vorite food plants nearby. It was concluded that the castor-bean plant was of little or no value as a trap plsmt for the beetles under usual field conditions.— Metzger (34) » Japanese beetles do not feed on all varieties of castor-beans, and the toxic property of varieties fed on it not at all uniform. Certain varieties do have some killing power, but it is not nearly so great as has been alleged by those advocating the use of this plant to destroy the insect.— Hawley and Metzger (27). An extension horticulturist received a letter from a gardener in northern New Jersey requesting an immediate visit to see what he had discovered concerning beetles on his lima beans. About 100 feet from the beans the gardener had planted a row of castor-beans j on inspection, he found the ground beneath the castor-beans covered with hundreds of dead beetles, probably Asiatic garden beetles (Auto- 8 erica cast an ea (Arrow)). The leaves showed evidence of feeding by the beetles. — Nissley (37) . In some parts of Manchuria the castor-bean plant was cultivated with other plants to prevent in.iury to the latter by insects. Adult beetles (Autoserica orientalis (Motsoh.)') that had fed on these leaves for 24 minutes in the lail)oratory became p€a*alyzed in 56 minutes and died after 157 hours; outdoors, 94 percent died in 4 days. Recovery from the paralysis was 6 percent outdoors and 35 percent in the laboratory. — Tsuchiyaroa (48) . - 6 - Ants, — To protect plants from ants the natives of Brazil grow castor-bean plants in their gardens* If the seeds are placed on the glowing fuel in the combustion chamber of an ant-fumigating apparatus, the fumes form a deposit in the nest which not only kills the ants but prevents reinf estation.— Gobbato (21, p, 304). Flies, — A oafe proprietor who had placed a castor-bean plant in his dining-room was surprised to find all the flies in the room dead beneath the plant. This statement has bean questioned, however, by- people who have found no trace of dead flies near or beneath this plant,— Car ri ire and Andre'' (15, 16) ♦ This plant was stated to be efficacious in freeing rooms of insect life, the leaves containing a substance fatal to flies and other insects,-- ^Anonymous {1) • Mosquitoes, — The Indian Medical Record for March 16 [1893] is quoted as follows: According to a Bombay newspaper the castor-bean plant gives protection against mosquitoes. In Egypt it is planted about the houses to drive the insects away. In towns, a better plan is to have the growing plants in pots and to bring them into the house for a day or two at a time. It was reported that the mosquitoes were killed by a poison found on the under side of the leaves, and if a dozen leaves were placed about a room swarming with mosquitoes, the insects would disappear without leaving any deed lying about. — Anonymous (3). Castor-bean plants helped to drive mosquitoes away.— Von Mueller (50, p. Ug?). Castor-beans planted near a house in New Jersey had no repellent effect on mosquitoes.— Smith (43, p. 543)* During the winter of 1901 a great deal was reported in the news- papers about the cultivation of this plant to keep mosquitoes away. These notes were based mainly upon the report of a consul from Veaa- ezuela, who had castor-bean plants growing profusely aroimd his residence. Seeds from these particular plants were brought to the United States and planted on the groxmds of the Department of Agri- culture in Washington, D, C,, and also in New Jersey, but observations indicated that mosquitoes were not at all deterred by the plants. In 1903 another consul reported a similar belief among the natives of Yucatan, and he also confirmed this belief to a certain extent experimentally. An Indian journal reported that six potted castor- bean plants that had been placed in a room were thickly covered by mosquitoes, which seemed "to be actually invigorated by the apparent- ly stimulating effect of their new quarters." In experiments in Algeria castor-bean plants were found to be without effect as deter- rents against mosquitoes.— Howard (29, pp. 23-25). Pttrta of Castor-Bean Plants Tested as Inseoticldes Deceotlon and juioe of plant.— A decoction of the leaves was used to destroy aphids and other insects.— Carri We and Andre' (16) • Jtd.o« from the leaves and gresn pods had only a slight effect on honeybees.— Uolndoo and Sievers (S3, p« 9)« The sap killed beetles (Cleonus) Bothynoderes puncttventrla (Gem*) in RujBanla*— Qrinberg mien nevly hatohed grasshoppers vere confined in screened cages over young, suooulflnt planta, half of them were dead at the end of 48 hours, one-fourth nore in 72 hours, and the reioainder in 96 hours* Only slight feeding was done on the plants.— Ssiith (44, p. "^66) » Brtraots of feeds and leaves.— Aa alcobollo extract of castor* bean seeds, iriien reasonably strong and used with so&p, was inef- ficient against three species of aphids, and whm fod to silkworms without soap it had no effect on then. A benzene extract of the seeds, when exceedingly strong and used with soap, was efficient against one of these aphids, but the control aixtxire killed half us many.— Mclndoo and Sievers (38, p. 9). Water and acetone extracts of the seeds and leaves killed less than 50 percent of the mosquito larvae tested and were not toxic to grasshoppers.— Hartsell and Wilcoxon (26, p. 136). Ricin, a toxic protein, and rioinine, aa alkaloid, are known to ooour in the seeds as well as other parts of the oastor-bean plant. Ihile it is known that both these oompounds are poisonous to rex^e- brates, little is known of their effect on insects. In tests by Pales a 1-percent solution of riein in water caused no mortality of flies, and a 1-peroent solution of rioinine in acetone oansdd only l-perosnt Bortallty»~Haller and Holndoo (25)» Grasshoppers fed for 7 days on irtieat plants dusted with rloia wor« not appreciably affected, although their bodies beoane covered with the irtilte powder. Preparations of rloln and rioinine, incor-^ porated in bran-nash baits and fed to grasshoppers, also showed no toxicity lAatever. Ihe utility of the oastor-besn plant as an insecticide awaits the proper cheoloal methods of extracting the speoiflo toxin for lns«ots»-~Hartiell and Wilcoxon (26, p* 138). Rloin and rioinine were tested against oodling moth larvae by tiie apple-plug method. These materials were used at the rate of 4 pounds per 100 gallons of water or water containing 20 percent of alcohol. Following the applloation of ricin 98 percent of 101 plugs, and of rioinine 1 percent of 98 plugs, were wormy and none were stung. Of 95 plugs treated with lead arsenate at the same - 8 - rata, 18 percent were wormy and 16 percent stung, and of 93 check plugs (water plus alcohol) 95 percent were wormy and none stung*— Si egler and^ coworkers (42) ♦ A mixture containing ricin, the toxic ingredient in castor-bean, was the least effective material used against the European red mite in 1942«— Boxume and ^itcoinb (15)» Unsatisfactory materials tried in 1942 against the common red •pider on greenhouse plants included a preparation containing castor- bean extract (ricin) Ifhitcomb and coworkers (61) • A spray containing castor-bean extractives in 1943 was inef- feotive against the onion thrips, chiefly because of its oily nature and poor wetting qualities*— Bourne (l2) . Powdered or crushed seeds*-- 'The powdered beans or husks, free from oil, killed all the honeybees tested} but some of this powder, extracted with a 10-percent solution of sodium chloride, apparently did not kill any of the bees* The powder had no effect on webworms, but had a slight effect on silkworms, flies, and grasshoppers*— Uclndoo and Sievers (33, p* 9) * Crushed castor-bean seeds incorporated in bran-mash baits were not toxic to grasshoppers*— Hartsell and '^ilcoxon (26, p* 136)* The ground cake of the castor-bean had no effect on fly laznrae in manure*— Cook and Hutchison (18, p* 4)* Castor-bean cake has been used as an insecticide in India*— Roark (41, p. 34). Castor oil*— [No attempt has been made in this review to include refersnoes to derivmtivM of castor oil useful as inseo- ticides or adjuncts*] Castor 6il, either alone or mixed wildi sugar, attracted houseflies and was an active poison for them* Since other oils, e* g*, olive or nut oil, had no such toxic action, the action of castor oil was not merely mechanical* Adding 2 drops of orotom oil to 1 ounce of castor oil greatly increased the toxio action on flies*— Boye'' and Guyot (14) » The following poisonous bait was recommended for houseflies in dwellings in Franoei Castor oil SO gm*, oroton oil 2 dropsy mixed with sugar or molasses* The effect was stated to be in- stantaneous*—Chavigny {17, p* 510)* During the fly plague in Germany in 1930 castor oil was used as one measxire of control* It had a very toxio effect upon adult flies, and was readily taken by them if it was mixed with sugar or mola88e8*>*f(xerasa39!rJ«Belchsgesundheitsamt (20, p* 30)* Attempts to Develop a Conmercial Insecticide from the Castor-Bean Plant An insecticide derived from the leaves of the castor-bean plant was reported irtiich could be produced commercially both for household-pest extermination and for agricultural uses*— Reimold (40) • Id. an editorial discussing the various uses of castor-beans, it Was said -Uiat the povdered leaves produce an insecticide nhioh has been extensively tried, especially in citrus groves, and found effective in repelling aphids, mosquitoes, -whiteflies, and mist mites*— Anonynoxui (4)* A new proprietary spray containing an eoctract from leaves of the castor-bean plant was claimed to have been highly effective against all kinds of inject pests, operating both as a contact and as a stomach poison, and was stated to have been used in large-scale experiments, principally in Florida, for the protection of garden truck and citrus fruits.— Qioleoker] (28) * Florida entomologists tested a liquid castor-plant product which was placed on the market in 1940 and early in 1941, but it was \m- satisfactory for control of five species of insects*— Anonymous (6^)* It was reported in 1942 that a oomraeroial company was producing insectioidal toxins derived from the castor-bean plant* Ml the toxins in the plant had not been isolated, but the products were described as satisfactory for th« control of scale insects and several species of spiders in Florida citrus groves and in New England apple orchards* Castor-bean extracts were said to be suit- able for agriooXtural inseotioides, but not for household use*— Anonymous ([s) • See also Anonynous (?) * Mbl inseoticide from the extractives of the leaves and other parts of the oastor-bean plant, called Spra-East, at first was made In liquid form, and iriien diluted 1 part to 60 parts of water served well in the citrus groves of Florida* Ihe dry Spra-East, developed later, was even more potent and more successful; 4 pounds of it were used in 100 gallons of water* Insects reported as controlled by Spra-East include many infesting beans, beets, oabbagt^ cucumbers, potatoes, spinach, tomatoes, melons, lettuce, and peas*— (TOood] (23). A patent pertains to an insecticide, containing extracts of the leaves and stalks of the oastor-bean plant, irtiich is effective against dog and cat fleas, the sticktight flea, diicken lioe, and mites.— Van Over (49) • A commercial insecticide made from the castor-bean plant was reported to have excellent wetting-asd spreading qualities and to be - xo - promising against certain aphids and the onion thrips. It acted slow^ ly against the Mexican bean beetle and was considei^ably repellent so •that there was little feeding.— ■Anonymous (_8) • An inseoticidal principle possibly is present in the castor^ bean plant only under certain conditions with respect to variety, cultural practice, and enTironment* It would appear that the accepted use of the castor-bean plant as a soxirce of insecticide awaits the ^ isolation, identification, and methods of analysis of the specific substances toxic to insects*— 'Haller and Hclndoo (25) • - 11 Literature Cited (1) ANONYMOaS. 1886, Ricinus communie as an insect powder, Chem, and Drug, 29: UIO. (2) I892, Cultivation of larkspur and castor oil plants for purpose of destroying locusts. Agr, Qas, N, S, Wales 2: 18-19. 1893* ^ mosquito exterminator, N, Y. Med, Jour, 57? ih) 19^. Castor Tjeans. Indus, and Engin. Chem, 32: I35-I36, (5) 19H2. iBiproTes castor insecticide. Soap and Sanit, Chem, 18 (U): 113, (6) 19^. Agricultural insecticides. Soap and Sanit. Chem. 20 (1): 119, 121, 123, (7) 19^. Chemurgy marches on in 19^3. Chemurg, Digest 3 (l) : [l], (g) I9HU, Bourne reports on castor insecticide. All* [Agr, Insecti, and Fungi,] Hews 2 (6): 3, (9) BARS, 0, S. 193^* Regarding castor beans and grasshopper control. Coop*, ext, work in Agr. and Home Scon., Nehr. Agr. Col, [Processed letter to agricultural agents, 3 pp.] (10) BEAR, T, B. 1938. Castor harriers, Ooxxntry Home 62 (1): 30. (11) BORTH, C, 19^2, Pioneers of plenty; the story of chemurgy. UlO pp. Indianapolis and Hew York, (12) BODRHS, A, I, 19^3* Control of onion thrips. Mass, Agr. Ezpt, Sta, Bol. 398 (Ann, Rpt, 19^2): 35-36. (13) and WHITCOMB, W, D, 19^2, Summer treatments for the control of Suropean red mite. Mass, Agr. Sxpt. Sta, Bui, 388 (Ann, Rpt. I9U1): 52, - 12 - ilh) BOYS, &. , and GOTOT, E, 1919. La lutte contre les mouches. Jour, de Phana. et de Chim. 19: 220-221. (15) CAEElfeffi, E. A., and MIJRB, E. 18S2, Le recin conune plante d'appartement insecticide. Rev, Hort. [Pari a] 5^: 53 (16) 1882, Le ricin ditruit-il les mouches? Her. Hort [Paris] 5^: 376. (17) CHATIOmr, P. • 192^, Les anlmaui parasites de I'horame et de 1 'habitation, ^7 pp. Paris. (18) COOK, P, C, and HUTCHISON, R, H. 1916. Experiments during 1915 destruction of fly larvae in horse manure, U, S. Dept. Agr. Bui. UOS, 20 pp. (19) CCIRAZE, C. Jj 1938, Growing castor beans will not control grasshoppers. Seed World l^3 (11): 28, (20) EJSRI^^YJ-REICHSGESUKDHSIT§A14T. ^ 1930* Di® Pliegenplage und ihre Bekaarpfung. Bd, 2, 36 pp. Berlin, (21) GOBBATO, C, * I92I+, Notas sobre agricviltura. Lavoura 28: 303-30^, (22) GONZALES RIOS, P., and VIAYORAL RBINAT, A. 1931. EL cultivo del aguacate en Puerto Rlco, Puerto Rico Insular Sta. Cir. 93, 3U pp. (23) [GOOD, J. E.] 19^3* Urges American castor plantings. Soap and Sanit, Chem. 19 (11): 123. (2U) QRINBERG, S, 1932. La lutte contr* le Cleonus punctiventris en Roumanle, Ann. de Gembloux 38: 80-82, (25) HALLER, H, L,, and McINDOO, H, 3, I9U3, The castor-bean plant as a source of insecticides, (Scientific Note) Jour. Bcon. Ent. 36: 638, (26) HARTZm, A,, and WILCOXON, P. I9U1, A stirvey of plant products for insecticidal properties, Boyce Thompson Inst. Contrlb. 12: 127-lM-l. - 13 - (27) HAWiSY, I. M., and MBTZGER, 7, V. 19^0, Teedlng habits of the adult Japanese beetle. U. S« Dept. A«r. Cir. 5^7, 31 PP. (2g) [HOILZCEER, E.] 19Uo. [Xxtract of castor-bean plant as Inseetielde.] Science 91 (2362, sap.): IK (29) BOWiBS, L. 0. 1910. Prerentire and remedial work against mosquitoes. S. Bur. Snt, Bui. 88 , 126 pp« (30) OTSOH, f. P» 1920* She tea shot-hole borer inrestlgatlon. Ceylon Deot. Agr. Admin, ^t, 1919l Oil. (31) LAJmSTK, B., Jr. 1932. Castor oil bean vs. Japanese beetle* Tlorists* Sxch. 79 (18) J 35. (32) LASBBXTH, C. H. 1932. A new way to destroy the Japanese beetle. 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