Summary of experiments with DDT to control the Japanese beetle


Material Information

Summary of experiments with DDT to control the Japanese beetle
Physical Description:
22 p. : ; 27 cm.
Fleming, Walter E ( Walter Ernest ), 1899-
United States -- Bureau of Entomology and Plant Quarantine
United States Department of Agriculture, Agricultural Research Administration, Bureau of Entomology and Plant Quarantine
Place of Publication:
Washington, D.C
Publication Date:


Subjects / Keywords:
DDT (Insecticide) -- Testing   ( lcsh )
Plants -- Effect of DDT on   ( lcsh )
Japanese beetle -- Control   ( lcsh )
federal government publication   ( marcgt )
non-fiction   ( marcgt )


Statement of Responsibility:
by Walter E. Fleming.
General Note:
Caption title.
General Note:
General Note:
"May 1947."

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 030293359
oclc - 780098957
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Full Text

May 1947 E-724

United States Department of 42i i~ature
Agricultural Research Administration
Bureau of Entomology and Plt Quarantine


By Walter E.
Division of Fruit Insect uveioas

Studies with technical DDT for the cootl cf the ""ture stages of the Tapanese beetle ( Japonica. Newman) in the
soil and for the protection of fruit and foliage from attack by the adult beetle were conducted in Maine, Massachusetts, Vermont, Rhode Island, Connectiout, New York, New Jersey, Pennsylvania, Delaware, Maryland, Virginia, North Carolina, and Ohio. This report summarizes the results obtained during the period from 1943 through 1946.

Formulation of MDT Dusts and Srays

When this study was undertaken, few commercial preparations
of DDT were available, and it was necessary to prepare special dusts and sprays. Later commercial formulations were used. In general, it was found that the effectiveness of the treatment was dependent more upon the amount of DDT applied than upon the formulation.

Dusts.--The dust formulated at the laboratory for the treatment of turf and cultivated land contained 10 percent of technical DDT, 87 percent of pyrophyllite or talc, and 3 percent of tricalcium phosphate. The DDT was micronized2/ with an equal weight of pyrophyllite or talc and then mixed with additional diluent and

l_ Personnel of the New Jersey Agricultural Experiment Station, the Connecticut Agricultural Experiment Station. the Ncrth -arolina Department of Agriculture, and the Divisions of Japanese Beetle Control, Insecticide Investigations, and Forest Insect invetgat.o of the Bureau of Entomology and Plant Quarantine assisted in certain phases of this investigation. The assistance of various eers of the staff of the Japanese Beetle Laboratory in conducting this investigation is acknowledged.

2/ This material was micronized through the co, y the
Micronizer Processing Company, Inc., Moorestow. N 7L


tricalcium phosphate. This dust flowed freely in the mechanical seeder and spreader, and when 250 or more pounds were applied per acre a uniform distribution was obtained. Later it was found that commercial dusts containing pyrophyllite or tale were satisfactory, but that those made with a clay were too adhesive to flow properly in this equipment.

The amount of DDT required for the treatment of potting soil is very small. 'For this treatment the 10-percent dust was diluted further so that it contained 2 percent of DDT, or a commercial dust of this concentration was used, in order to have the material of sufficient bulk that it could be mixed uniformly throughout the mass of soil.

For dusting foliage the amount of DDT in the dust was governed by the type of equipment., A 10-percent dust was used in the small hand dusters, and a 1-percent dust was used when the treatment was applied by airplane.

waer-disesible DD.--In the early tests with sprays the
technical DDT was micronized with an equal weight of pyrophyllite, and fish glue equivalent to 1/16 of the weight of the solids was added as a wetting agent while the material was being prepared for spraying. Later it was found that the commercial water-dispersible DDT was equally as effective as the foregoing spray and much easier to handle in the field. Sprays prepared from 25 to 50 percent waterdispersible powders to contain the same amount of DDT per 100 gallons were equally effective in protecting plants from attack by the adult beetle, but when the powder contained much less than 50 percent of DDT an objectionable conspicuous deposit was left on the fruit and foliage. Throughout this paper, wherever mention is made of the use of DDT in water suspension, the quantity indicated refers to the quantity of actual technical DDT* in the form of a water-dispersible powder, unless otherwise stated. In the earlier experiments summeroil emulsion was used with the water-dispersible powder as a sticker; later it was found that the addition of a sticker was not necessary and that it tended to leave an excessive residue of DDT on the fruit.

DDT emulsions.--Two commercial DDT emulsions were applied by an airplane. one contained 30 percent of DDT with a methylated naphthalene as a solvent, and the other contained 25 percent of DDT with an aromatic petroleum derivative.

DDT solution.--A solution of DDT was applied by airplane and also from the ground by a mist blower. This solution contained

1 pound of DDT in 1 quart of xy1ee and 3 quarts of deodorized


Protection of Plants from Attack by Adult Beetles

Since adult Japanese beetles usually attack the upper portion
of a plant and then work downward and inward until they have consumed all the fruit and foliage, in applying experimental sprays and dusts care was taken to cover all portions, particularly the extending branches at the top.

The sprays and dusts killed many of the beetles that were hit during the application, and the residue on the plants afforded prow tection against beetles that came subsequently to them. DDT does not seem to be a strong repellent, since the residue did not prevent beetles from alighting on the sprayed or dusted plants. However the beetles that walked over or started to feed on these plants soon became paralyzed and died.

DT was used under many conditions to protect various crops and ornamentals fro& injury by the adult beetles. The tests conducted and the results obtained may be su -i02 *i~ly as follows:

Applo.--In 1944, 1945, and 1946 at Bridgeton, N. J., one application of a spray containing 1 pound of DDT per 100 gallons of water to Yellow Transparent and Williams Early Red apple trees early in July, just as the beetles were beginning to attack them, afforded complete protection to the fruit, which was harvested by the middle of July, and to the foliage throughout the sxmer. An application of this spray to Williams Early Red apple tress on May 31, as a subsfitute for the last arsenical cover spray for the codling moth, was inadequate for control of the Japanese beetle, because now growth during June and July was not protected from attack.

Nootarino.--A few nectarine trees at Dayton, N. J., were sprayed with DDT, 1 pound per 100 gallons of water, in 1943 after the beetles had become established on the and were causing severe damage to the fruit. All the beetles on these trees were destroyed and no further injury occurred. The adjacent tress, which were not sprayed, were completely defoliated, and all the jt waf consumed by the betles.

Peaho--In Now Jersey peaches ripen from the middle of July
until in September. The foliage of all wvaieties is subject to


attack by the beetle, and the fruits of the early-ripening varieties are often severely damaged. In 1943 through 1946 blocks of
bearing trees in commercial orchards at Cranbury and Bridgeton, N. J., were sprayed with water-dispersible DDT. The following varieties were in these blocks:

Cumberland J. H. Hale N. J. 135 Sunhigh
Elberta Newday Raritan Rose Triogem
Goldeneast N. 3. 109 Redrose
Goldenglobe N. J. 118 Summererest

Sprays containing 1/4, 1/2, 3/4, and 1 pound of DDT per 100 gallons were applied early in July as the beetles were beginning to invade the trees. All these sprays killed many of the beetles on the trees at the time of application, but only the spray containing
1 pound of DDT afforded complete protection to the fruit and foliage throughout the summer.

Plum.--At Dayton, N. J., in 1943, a few nonbearing your. plum trees were heavily infested and partially defoliated by tM ieatles. Spraying with DDT at the rate of 1 pound per 100 gallons dest2oyed all the beetles and no further injury occurred.

Grape.--Tapanese beetles attack the foliage of all varieties
of grapes and damage the berries of those varieties which ripen during August. Most of the vines grow rapidly during Tuly, so that more than one application of a spray is required to protect to foliage. From 1943 through 1946 experiments with DDT wer conrducted in a commercial vineyard at Holmdel, N. J. 'When 1/2 o pound of DDT was added to 100 gallons of bordeaux mixture in the preblossom, petal-fall, and pea-stage sprays for control of the grape berry moth (Polychrosis viteana (Clam.)), the last sprey being applied late in June, an additional spray 2 to 3 weeks Inter with 1/2 pound of DDT in 100 gallons of water to cover the new groh afforded complete protection. When DDT was not used for control of the grape berry moth, protection against the Japanese beetle was obtaiLred by spraying with 1 pound of DDT per 100 gallons of bordeaux mixture late in Tune and 2 to 5 weeks later with 1 pound of DDT per 100 gallons of water. These sprays protected the following varieties from injury by the beetles:


Butler Etta Massasoit Portland
Caco Fredonia Missouri Riesling Regal
Catawba Herbert Muscat Salem
Champion lona Niagara Sheridan
Concord Zanesville Ontario Telegraph
Cottage Lindley Perkins Wilder
Delaware Martha Pocklington Woodruff Red

occasional feeding occurred on the sprayed foliage of Brighton, Brilliant, Clinton, Lutie, Urbana, and Vergennes.

Hungarian was the only variety that was not adequately protected by these sprays; extensive feeding occurred on the sprayed foliage, and the beetles attacked the fruit.

Blue'brry.--In recent years the Japanese beetle infestation in most of the commercial plantings of blueberries in New Jersey has been so light that no special spray has been required. However, some plantations, particularly those adjacent to general farming areas, have invasions which cause damage to fruit and foliage. A heavily infested block, including the varieties JUne, Ranoocas, Scammell, and Stanley, was found at New Brunswick, N. J., in 1943. Early in July these plants were sprayed with 1 pound of DDT per 100 gallons of water. This spray protected the fruit and foliage for 2 weeks. Then the beetles began to attack the terminal growth which had developed after the application of the spray. The plants were resprayed and no further damage occurred.

ornamental trees and shrubs.-DuA'ing 1944, 1945, and 1946
several hundred ornamental trees and shrubs at Bridgeton, N. J., Rye, N. Y., and Blowing Rock, N. C., were sprayed with DDT at the rate of 1 pound to 100 gallons of water. The following species were included:


Fagus mdifolia American Beech
Quercus montana Chestnut Oak
palustris Pin Oak
Tilia americana American Linden
europaea European Linden
Ulmus americana American Elm


Shrubs and Vines

Acer Japonica Fullmoon Maple
palmatum Japanese Maple
Azalea calendulacea Flame Azalea
mollis Chinese Azalea
Berberis thunbergi Japanese Barberry
Buddleia davidii Butterflybush
Chaenomeles lagenaria Flowering Quince
Cotoneaster sp. Cotoneaster
Lespedeza sp. Lespedeza
Malus floribunda Japanese Flowering Crab
Parthenocissus quinquefolia Virginia Creeper
Prunus serrulata Oriental Cherry
triloba Flowering Plum
Rosa spp. Various hybrid tea roses
and the climbing roses
Dorothy Perkins and
Paul's Scarlet

The DDT protected the foliage, but did not prevent the beetles from damaging the blooms. When the plants did not make much growth, one spray, applied late in June or early in July, was sufficient to
protect the foliage. The plants that grew considerably during July required a second application 2 weeks later.

Late in July 1945 ornamental trees and shrubs at Fort Schuyler, N. Y., were sprayed with a solution of DDT in xylene and kerosene by means of a mist blower. The infestation in the traes and shrubs was destroyed, and no further injury occurred during the summer.

Flowering garden plants.--During 1944 and 1945 several beds of
flowering garden plants, including marigolds, snapdragons, and zinnias, at Bridgeton, N. J., were sprayed with DDT at the rate of 1 pound per 100 gallons. A spray applied early in July protected the plants for 2 weeks. A second spray, applied 2 weeks later, afforded protection to the plants throughout the sumner,

Field crops.--Soybeans, including the varieties Chief, Earlyana, Gibson, Illini, Lincoln, Macoupin, Mingo, Patoka, Richland, and
Viking were sprayed with DDT, 1 pound per 100 gallons, at Dover, Del., In 1945. The spray killed many of the beetles on the plants and afforded protection for about 1 week. As the plants made considerable growth during this period, it was necessary to repeat the application at weekly intervals.

on Tuly 25, 1945, a plot of soyba&k -d s-ia plots of
corn at Beltsville, Md., were dusted -itl U, ecn DDT. Most of the beetles on the soybeans were killed, and a week later only an occasional beetle was seen on the plants. Wh~en the dust was applied to the corn, beetles were feeding on 10 to 50 percent of the silks, Tw days later no beetles were present, but after a week many were feeding on the old and newly formed silks.

About half of a 30-acre field of hybrid corn near LebanoL, Pas, was sprayed or dusted with MT on August 2, 1946. The following formulations were used:

A solution prepared by dissolving 1 pound of DDT in
1 quart of xylene and 3 quarts of kerosene.
A commercial emulsion containing 30 percent of DDT
dissolved in methylated naphthalene and an unknown
emulsifier, diluted 1:.3 with water,
A commercial emulsion containing 25 percent of DTY
dissolved in an aromatic petroleum derivative and an
unknown emulsifier, diluted 1:1 with water,
A dust containing 1 percent of micronized DDT.

All treatments were applied by ex.~~ae which flew low over
the field. The dust was applied at the~ r-ate of approximately 45 pounds per acre and the solutions and emulsions at about 1-1/3 gallons per acre. Shortly after the application of~ these treatments the beetles showed evidence of poisoning, and within an hour many of them had fallen to the ground. Three daslater there were
65 percent fewer beetles on the dusted corn and 93 percent fewer beetles on the corn sprayed with the solutions than in the adjacent untreated plot. Seven days later, although the population in the treated plot had not changed, the beetles were feeding on the newly formed silks. It was evident that more than one application of DDT would be required during the milking period to control the beetles on corn,

Control of the ImmAtwzota in the Soil

In the tests for control of the immature stages in the soil,
adult beetles were able to burrow into soil treated with DDT at rates up to 50 pounds per acre without any detrimental effect. furthermoree, eggs hatched and p.tpe developed normally in treated soil. The only stage susceptible to poisoning by DDT was the larva.


Pound for pound, DDTr is about 100 times as toxic to the larvae as is load arsenate, the material used most extensively in the past for their control, Newly hatched larvae succumb mre quickly then do fully grown third instar8. DDT is not effective at 400 F., when the larvae are dormant, but the speed of toxic action increases progressively with thne rise of the temperature above this point,

The rate of toxic action was th& more rapid in sends than in other types of soil, but there was no significant difference in the rates in gravelly loams, sandy boas, boas, and silt 108118. DDT poisoned the larvae more rapidly in well-drained soils than in poorly drained, inadequately aerated soils. The rate was retarded by the addition of organic matter, such as peat, but was not inhibited by inorganic fertilizers, such as lime, calcium phosphate, potassium nitrate, ammonium sulfate, and calcium cyanamide, or by aluminum sulfate, ferrous sulfate, or sulfur.

In laboratory studies the effectiveness of DDT in representative soils from the Piedmont Plateau, the Appalachian Mountains, and the Coastal Plain did not change in 3-1/2 years. It appears that DJDT will remain insecticidally active in the soil for a long period,

The most effective control of the larvae was obtained when DDT was in the soil at the time the eggs were hatching. Teatments were applied to established turf and to cultivated land in the spring of 19449 1945,, and 1946 with the object of destroying the brood which hatched during the summer. The tests conducted and results obtained may be summarized briefly as follows:

Turf .-In May 1944 DDT was applied as a dust at the rate of
25 pounds per acre to infested turf at Totawa, N. 3. The treatment killed one-third of the larvae before pupation. It reduced the 1944-45 brood 90 percent by September and 96 percent by the following "Iay. The 1945-46 brood was reduce! 98.9 percent, and the 1946-47 brood 99.8 percent, by September 1945 and 1946, respectively.

In may 1945 DDT was applied to turf at Blowing Rock, N. Cot at the rate of 25 pounds per acre. Most of the area was treated with the 10-percent dust,, but a small portion was sprayed with a suspension of DDT, at the rate of 25 pounds of DDT in 1,000 gallons
eracre. In the dusted area the 1945-46 brood was reduced 78.6
pojrcent by September and 91.6 percent before pupation in JUae. In


the sprayed area the reduction was 67.4 percent and 90.2 percent,
respectively. By October 1946 the DDT dust had reduced the density of the 1946-47 brood by 97.4 percent, and the spray by 64.4 percent.

In May 1946 DDT was applied to turf at the rate of 25 pounds per acre as a dust at Blairstown, N. J., Orange, Conn.s and Northampton, Mass., and as a spray at Blairstown, N. J., and New London, Conn. The treatment killed 25.8 percent of tha 1945-46 brood at New London and 71 percent of this brood at Orange before pupation. By aid-September the dust had caused a reduction it t 1946-47 brood of 99.7 percent at Blairstown, 84.0 percent at Orange, and 98.5 percent at Northampton, and the spray had killed 99.5 percent at Blairstown, and 82.7 percent at New London.

In July 1946, before most of the eggs had hatched, DDT was applied both as a dust and as a spray to turf at Orange at the rate of 25 pounds per acre. By mid-September the dust had reduced the 1946-47 brood by 88 percent and the spray had reduced it by 83 percent.

One application of DDT as a dust or spray to the surface of
established turf at the rate of 25 pounds per acre before the eggs hatched, reduced the larval population to negligible proportions, and from the present indications the treatment will be effective for several years.

Cultivated land in commercial nurseries.--To determine the
possibilities of DDT for eradicating the larvae in the soil in beds and plots in commercial nurseries, to satisfy requirements of the quarantine, in the spring of 1944, 1945, and 1946 treatments were applied at the following commercial establishments in New Jersey where various types of ornamental stock were being grown: Browns Mills, Chatsworth, Kingston, Magnolia, Pemberton, Ridgewood, Riverton, Rutherford, Shiloh, Vincentown, Wayne, and Woodstowno

DDT was applied as a water-dispersible powder to established beds at rates ranging from 10 to 50 pounds of DDT par acre, 1,00 gallons of the spray being used per acre. The material was not mixed into the soil. There was a pronounced reduction in the density of the larval population by mid-Septenber in all treatments, but
complete elimination was not obtained even with 50 pounds of DDT per acre.


The DDT was also applied as a dust at rates ranging from 10 to 55 pounds per acre and mixed by cultivation with the uppar 3 to 4 inches of soil. When less than 25 pounds per acre was applied, few of the plots were entirely free of infestation by mid-September, but at the higher dosages only an occasional larva was found. vTith the 25-pound treatment 99.9 percent of the population eliminated. Results equally as good were obtained with the water-diDsper3ible DDT, applied as a spray end mixed with the upper 3 to 4 inches of the soil.

Plots at Riverton and Woodstown, which were treated by applying DDT at the rate of 25 pounds per acre and mixing it 7Lth the upper
3 to 4 inches of soil, were left undisturbed for 2 yt)z'3. This treatment eliminated two successive annual broods.

The results indicate that DDT applied to nursery beds and plots in the spring at the rate of 25 pounds per acre and mixed with the upper 3 to 4 inches of soil will practically eliminate the larvae by mid-September. The indications are that the treatment will be effective for several years. DDT appears very promising for the traatment of beds and plots to satisfy the requirements of q quarantine.

Potting soil.--To determine the possibilities of )a for the
treatment of soil used in commercial greenhouses for potoing plants, to satisfy requirements of the quarantine, DDT was mixed with different soils at rates ranging from 2.7 to 108 grams '. ui, c yard. At 800 F. complete mortality of newly hatched larvae was not obtained with 2.7 grams in 2 weeks, but all the larvae I '_ -A
with 5.4 grams in 5 days, with 10.8 grams in 4 days; 2" grams in 3 days, and with 54 or more grams in 2 days. Third-".nstr larvae were much more resistant; to obtain complete morte 'y requ. red 7.2 weeks with 10.8 grams, 4 weeks with 27 gratsiW d C wkeks with 54 grams.

Twenty-seven grams per cubic yard, which is eqti pounds per acre, seemed to be about the optimum mouiat for the treatment of potting soil. Greater amounts of DDT did not accelerate very much the rate of poisoning and increased the htzar A of injuring plants; lesser amounts prolonged the time required to eliminate the infestation too much to be practical. During the summer, if proper allowance is made for the incubation of the eggs, a period of 3 to 4 weeks would be required from the time the eggs are laid in soil treated with this dosage until it was free of infestation.


There is a close correlation between the temperature of the soil and the rate of poisoning. To kill third-instar larvae in soil treated with 27 grams of DDT per cubic yard required 4 weeks at 800 F., 6 weeks at 700, 8 weeks at 600, and 16 weeks at 500.

The type of soil influenced the velocity of poisoning with 27 grams of DDT per cubic yard. At 800 F. to kill third-instar larvae required on an average 2.8 weeks in the sands, 4.4 weeks in the sandy loams, 4.1 weeks in the loans, and 399 weeks in the silt loams.

The addition of ammonium phosphate, ammonium sulfate, calcium cyanamide, calcium phosphate, calcium sulfate, and sodium nitrate to potting soil at rates up to 2.5 pounds per cubic yard did not inhibit the insecticidal action of DIT. Hydrated lime at rates up to 40 pounds per cubic yard did not modify the toxicity of the DDT to the larvae. The addition of organic matter tended to retard the velocity of poisoning.

The effectiveness of DDT in the different soils did not change significantly during 3-1/2 years. The addition of the fertilizers and organic matter to the soils did not modify the duration of the effectiveness.

Effect of DDT Treatments for Japanese Beetle
Control on Other Insects and Invertebrates

In studying the effectiveness of DDT dusts and sprays for control of the larvae and the adults of the Japanese beetle, it was the practice to make general observations on the effect of the treatments on other insects and invertebrates. When DDT was applied as a spray to fruit and ornamental trees and shrubs, all dead and dying invertebrates beneath the plants were collected and classified. Some representatives of the following groups were affected by DDT:

Araneida, Phalangida
Chilopoda Diplopoda
Coleoptera: Buprestidae, Carabidae, Cerambycidae,
Chrysomelidae, Cicindelidae, Coccinellidae, Curculionidae,
Elateridae, Lampyridae, Mordellidae, Scarabaeidae


Hexapoda (cont.):
Diptera: Calliphoridae, Larvaevoridae, Muscitae,
Rhagionidae, Saroophagidae, Syrphidae, Tophritidae
Hemiptera: Cicadellise, Miridae, Pentatomidae, Reduviidae
Hymenoptera: Andrenida*, Apidae, Braconidae, Emenlnae,
Formicidae, Ichneumonidae, Tenthbredixnidae
Lepidoptera: Geometeridae, Lasioampodae, Phalaenidae,
Odonata: Agrionidae
Orthoptera: Gryllidae, Mantidae

Many insects, including beneficial forms, were killed by DDT, either by being wetted by the spray or by gaming in contact with deposits on the foliage or on the ground beneath the trees. There is still much to be done to establish the effect of DDT on the beneficial insect parasites and predators, as well as on insects that assist in the pollination of important crops. In general, DDT appears to be somewhat less injurious to pollinating insects than is lead arsenate.

Spraying the foliage for protection against the Japanese beetle seemed to be of some value in controlling certain other pests. When applied to peaches, the spray reduced the injury to fruit by the oriental fruit moth (Grapholitha molesta (Busck))S/ and seemed to give some control of the peach tree borer (Sanninoidea exitiosa (Say))/. Substituting DDT for lead arsenate in the last arsenical cover spray for early apples gave better control of the codling moth (Carpocapsa pnomonella (L.)). When applied to grapes, DDT practically eliminated the grape leaf folder (Deamia funeralis (Hbn.)) and the grape leafhoppers (Erythroneura app.), and gave better control of the grape berry moth (Polychrosis viteana (Clem.)) than did lead arsenate. American holly (Ilex opaca Ait.) in a group of shrubs sprayed with DDT had few holly leaf miners (Phytomyza ilicis (Curtis)), but adjacent unsprayed plants had many miners. The spray also controlled the elm leaf beetle (Galerucella xanthomelaena (Schr.)) and the rose chafer (Macrodactylus subspinosus (F.)).

3/ Driggers, B. F. Laboratory test on the oriental fruit moth with special reference to DDT. (Scientific Note) Jour. Econ. Ent. 37: 120-121. 1944.

4/ Field tests of DDT to control the peach
borer. (Scientific Note) Jour. Econ. Ent. 37: 657. 1944.


The spray seemed to have no effo cn l grow larvae of
the bagworm (Thyridopteryx ephemeraefor,, ii awi)), the grape mealybug (Pseudococcus maritimus (Ehrh.)), or the Comstock mealybug (P wmstocki (Kuw.)), and did not control the grapevine aphid (Aphis illinoisensis Shimer), the rosy apple aphid (Anuraphis roseus Baker), or the apple aphid (Aphis 2iul Deg.). It seemed to have no effect on galls on grape vines.

MItes increased markedly on plants subject to attack by this pes following applications of DDT. On azaleas a spider mite (Tetranychus sp., probably bimaculatus Harv. or althaeae Von Haust.) increased rapidly after the spraying, and caused mottling of the foliage. The European red mite (Paratetranychus pilosus (C. and F.) increased rapidly on apples, peaches, and lindens sprayed with DDT, and in August it caused many of the leaves to drop prematurely. It was evident from these results that the control of mites is a problem that must be considered when DDT is used as a spray on foliage.

The application of DDT as a dust to the ground killed large numbers of insects which are found frequently on the surface of the soil or on low-growing vegetation, including many of the ground beetles, particularly of the family Carabidae, blister beetles, grasshoppers, crickets, leafhoppers, and leaf bugs. Sowbugs and crayfish in low spots were killed. Cutworms were usually absent from soil treated with DDT, but wireworms and earthworms seemed to be as abundant as in untreated soil. The effect of DDT on the many species of ants is uncertain; sometimes ants were absent, but in other cases they seemed to be as numerous as in untreated soil. Some garden slugs were killed by coming in contact with the dust, but after the residue had been washed from the blades of grass by rain, the treatment seemed to have no effect on them.

Effect of DDT on Plants

There have been very few cases where spraying the foliage with DDT at the rate of 1 pound per 100 gallons of water has caused any direct damage to the plants. ":o injury was observed on the following plants:

Deciduous fruits (all varieties that were sprayed):

Apple Grape Peach
Blueberry Nectarine Plum


Azalea calendulacea Flame Azalea
mollis Chinese Azalea
Berberis thunbergi Japanese Barberry
Buddleia davidii Butterflybush
Chaenomeles lagenaria Flowering Quince
Fagus grandifolia American Beech
Lespedeza sp. Lespedeza
Malus floribunda Japanese Flowering Crab
Parthenociceus quinquefolia Virginia Creeper
Prunus serrulata Oriental Cherry
triloba Flowering Plum
quercus montana Chestnut Oak
palustris Pin Oak
Tilia americana American Linden
europaea European Linden
Ulmus americana American Elm

Flowering garden plants:

Marigold Snapdragon Zinnia

Spraying with water-dispersible DDT may have caused some
chemical burning on the foliage of Japanese maple (Acer palmatum) and fullmoon maple (A. Japonica), but this is uncertain because these varieties are very susceptible to scalding by the sun during the summer. It injured slightly the blooms on roses and on petunias and definitely retarded the growth and reduced the yield of soybeans.

Applying DDT dissolved in xylene and kerosene with a mist blower did not damage the foliage of various deciduous trees and shrubs. Corn was not injured while in silk by dusting or spraying emulsions and solutions of DDT from an airplane.

Preliminary tests were made at the laboratory and conducted cooperatively with 54 commercial establishments in a number of eastern States to determine whether various plants could be grown satisfactorily in soil containing 25 pounds of DDT per acre, or 27 grams per cubic yard. The plants were grown in treated soil and compared with those in untreated soil. The results are indicated below.


plants Not Noticeably Affected by DDT in Soil


Beta vulgaris Common Beet
Brassica chinensis Chinese Cabbage
oleracee acephala Kale
capitata Cabbage
rapa Turnip
Capsicum sp. Pepper
Cucumis melo Muskmelon
sativus Cucumber
Cucurbita maxima Squash
Daucus carota sat iva Garden Carrot
Lactuca sativa Garden Lettuce
pas-tinaca sat iva Garden Parsnip
Pisum, sativwii Garden Pea
Raphanus sativus Garden Radish
Solanum melongena Garden Eggplant
tuberosum Potato
Zea mays Corn

Cereals and grasses:

Agrostis, alba Redtop
palustris Creeping Bentgras
tenuis Colonial Bentgrass
tenuis astoriana Astoria Bentgrass
Avena sp. Oats
Cynodon dactylon Bermudagrass
flactylis glomerata orchardgrass
Festuca elatior Meadow Fescue
rubra commutata Chewings Fescue
Hordeum vulgare Barley
Lolium perenne Perennial Ryegrass
Poa compressa Canada Bluegrass
pratensis Kentucky Bluegrass
trivi 'alis Rough-stalk Bluegrass
Secale cerale Rye
Stenotaphrum secundatum. St. Augustinegrass
Triticum sp. 'Wheat



Acalypha hispida Chenille Copperleaf
Acanthus montanus Acanthus
Acer palmatum Tapanese M.aple
Achilles ptarmica Sneezewort Yarrow
Aechmea calculate,
eaudata fasciata
AeSchynanthus pulcher Scarlet Basketvine
Ageratum sp. Ageratum
Aglaonema commutatum
simplex Chinagreen
AllAmAnda cathartica hendersoni Henderson Common Allamanda
Alpinia sanderae Banded Galangal
Althaea roses Hollyhock
Amomum cardamon Cardamon Amomum
'TAanas comosus Pineapple
Anthems tinotoria Golden Camomile
Arabis alpine Alpine Rockaress,
Araucaria. excels Norfolkisland Pine
Ardisia crenulat; Ardisia
U;F9_11a marmoRta Airplant Aregelia
spectabilis Showy Aregelia
tristis Bitter Aregelia
Arenaria verna caespitosa Moss Sandwort
Armeria sp, Thrift
Aronia arbutifolia Red Chokeberry
Aspidistra elation variegate Striped Aspidistra
Aster subcoeruleus East Indies Aster
Zomsoni frikarti Frikart Aster
Azalea indica Indies Azalea
kaempferi Torch Azalea
kurume Kurume Azalea
mollis Chinese Azalea
roamarinifolia Snow Azalea
rutherfordiana Rutherford Azalea
sander Sander Azalea
Begonia cocoinea x olbia
imperialism Imperial Begonia
maculata argentea Spotted Begonia
manicata aureo-maculata


Ornamentals (cont.):

Begonia metallica Steel Begonia
nitida odorata Glossy Begonia
rex A8samking Begonia
semperflorens Perpetual Begonia
Berberis mentorensis Mentor Barberry
verruculosa. Warty Barberry
Billbergia alberti Albert Airbrom.
nutans Bleurim Airbrom.
pyramidalis VioletriM Airbrom.
sanderiana Sander Airbrom
zebrina Zebra Airbrom
Buddleia sp. Butterflybush
Buxus sempervirens Common Box
sempervirens suffruticosa Truedwarf Box
Calathea makoyara TAakoy Calathea
ornata rossilineata Roseline Bigleaf Calathea
vandenheckei Vandenheck Calathea
Calceolaria, sp, Calceolaria
Calendula op. Calendula
Camellia japonica Common Camellia
C! mpanula carpatioa Carpathian Bellflower
persicifolia Peachleaf Beliflower
rotundifoli; superba Bluebells of Scotland
Canna sp. Canna
Catananche caerulea Blue Cupidsdart
Carus candelaris Candle Cactus
Chamaecyparis lawsoniana IAwson Falsecypress
nootkatensis Alauca Blue Nootka Falsecypress obtuse gracilis Slender Hinoki Falsecypress
pisifera, Sawara Falsecypress
Chlorophytum elatum, Bracketplant
Chrysanthemum sp. Chrysanthemum
Cibotium schiedei Mexican Cibotium.
Cissus discolor Begonia Treebine
rhombifolia Venzuela Treebine
sicyoides Ilaterwithe Treebine
Clerodendron thomsonae Bleedingheart Glorybower
Codiaeum, varietgatum Leaferoton
COleUS op. Coleus
Cordyline terminals Common Dracena
Coreopsistinctoria Calliopsis


Ornamentals (cont.):

Cornus florida Flowering Dogwood
Cotoneaster acutifolia Peking Cotoneaster
Crassula arborescens Crassula
Croton punctatus
Cryptanthus aceiiiis

Cryptomeria jap-)T-=0bbi Lobb Cryptomeria.
Ctenanthe oEL2Zi!--J,,ena
Cyclamen sp. Cyclamen
Dakhne cneorum Rose Daphne
Davallia fijit-,,-.1.Z, plumose, FiJi Davallia
Del2hinium sp. 1,arkspur
Dianthus cary,- ,p-nyUus Carnation
plumari,-,s Grass Pink
Dicentra spectabilis Common Bleedingheart
Dieffenbachia bausei Bause Tuftroot
leoni Leon Tuftroot
picta Variable Tuf troo t
splendens Whitespot Taf troot
Doronicum caucasicum Caucasian Leopardbane
Dracaena deremensis warnecki
frajEans massangeana. Massage I)racasna victoria Victoria Dracaena godseffians. kelleri Keller Dracaena 921dieana Goldie Dracaena.
Episica. cocci")
Erigeron jLte2,._- Oregon Fleabane
Euonymus fortuz.,"11 vs zatue Vinterareeper Euonymus
11 1 pa t o r 1 -1 --, t Ldri Mistflower Eupatorium
Euphorbia pul- ),-,.- na Oakleaf Poinsettia
Ficus elastica Indiarubber Fig
radicana variegat a Variegated Rooting Fig
Fittonia verschaffeltii Tall Fittonia
Fuc sp. Fuchsia
Ginkgo bilobe Ginkgo
Gypsophila re Creeping Gypsophila,
Hedera canai I-eLS'Te Algerian Ivy
helix English Ivy
Heliopsis sp. Heliopsis
Heliotropium Heliotrope
Hemigraphis c,-).
Herniaria Common Burstwort
Heuchera ro Rosemund Alumroot


ornamentals (cont.)

Hoffmannia ghiesbreghti
Homalocladium platycladum, Ribbonbush
Homalomena ailisiHoya, carnosa Common Waxplant
Hydrangea macrophylla Bigleaf Hydrangea
Hypericum sp. St. lohnswort
Iberis sempervirens Evergreen Candytuft
Ilex glabra Inkberry
opaca American Holly
Impatiens sultan Sultan Snapweed
Jasminum officinale affine
sambac Arabian Jasmine.
Tuniperus chi4ensis Chinese Juniper
communism Common Juniper
exeelsa Greek Juniper
Eorizontalis Creeping Juniper
scopulorum Rocky Mountain Juniper
9quamata Singleseed Juniper
virginiana Eastern Redcadar
Kalanchoe blossfeldiana Kalanchoe
Laburnum anagyroides Goldenchain Laburnurn
Lonicera henry Henry Honeysuckle
Magnolia soulangeana Saucer Magnolia
stellata Star Magnolia
Mahonia aquifolium. Oregongrape
Maranta arundinacea Bermuda Arrowroot
leuconeura kerchoveana Redspot Banded Arromroot
Matricaria tchihatchewi Silver Ball Turfingdais
W.edinilla magnifies.
Yiyosotis scorpioides True Forgetmenot
Nepeta mussini Persian Nepeta
Nephrolepis exaltata bostoniensiS Bostonfern
Nephthytis afzeli
Nidularium amazonica.
innocent purpureum
Ophiopogon japonicus Lilyturf
Pachysandra terminals Japanese Pachysandra
Pandanus baptisti
veitchi Veitch Screwpine
Papaver oriental oriental Poppy
Parthenocissua tricuspidata Japanese Creeper


ornamentals (conts):

passiflore alatocaerulea White Passionflower
Pelargonium. spe Garden Geranium
Pellionia daveauana
Penstemon garretti Garretts Penstemon
Peperomia 07-usifOlia Ovalleaf Peperomia
sandersi Sanders Peperomia
Petunia sp* Petunia
Philodendron cordatum Heartleaf Philodendron
phlox divaricate, 3weetwilliam Phlox
glaberrima Smooth Phlox
nivalis q-Irailing Phlox
Phyllitis scolopendrium cristatum Hartstongue Fern
Picea glauca White Spruce
pungens Colorado Spruce
Pieris japonica Japanese Pieris
Piles. muscosa Clearweed
Pinus mugo Swiss Mountain Pine
Polystichum sp. Hollyf ern
Potentille fruticosa Bush Cinquefoil
Primula veris Cowslip primrose
Pssudotsuga taxifolia Douglasfir
Pteris cretica. Cretan Breke
tremula Australian Brake
Pulmonaria saacharata Bethlehem Lungwort
Pyracantha coccinea lalandi Laland Firethoru
Rorippa nasturtium-e.ouaticum Watercress
Rosa sp. Rose
71us reflexes pictus
Salvia sp. sage
Sansevieria zeylanica Ceylon Sansevieria
Saxifraga sarmentosam Strawberry Saxifrage
Scindapsus aurens Solomonislands Ivyarum
Scirpus cernuus, Weeping Bulrush
Spiraea sp. Spirea
Taxus baccata English Yew
brevifolia Pacific Yew
cuspideta Japanese Yew
hiinnewelliana Hunnewell Yew
media Anglojap Yew
Teucrium, Zamaedrys Chamaedrys Germander
Thalictrum glaucum Dusty Meadowrue


ornamentals (cont.):

Thuja occidentalis -a Arborvitae
orientalis al Arborvitae
Tillandsia lindeniana TiI landsia
Tolmiea menziesi Pick-F -,Back Plant
Trachelospermum lasminoides "tarja8mine
Tradescantia fluminensis ntij,-- .xingjew
Tropaeolum, op. Nasturtium
Vaccinium sp, Blueberry
Veronica op.
Viburnum burkwoodi Bum--ood Viburnum
carlesi Kor -,-nspice Viburnum
dilatatum, Linden Viburnum
setigerum. Tea Viburnum
tanentosum Doublefile Viburnum
Vinca op. Periwinkle
Viola cornuta Horned Violet
odorata Sweet Violet
tricolor hortensis Garden Pansy
Vitis sp, Grape
Vriesia erecta Poelrex Vriesia
Weigela op. Weigela
Xanthosoma linden Lini, n Alalanga
Zinnia op. 0

Plants Definitely Retarded by DI T in Soil


Allium flavum Yellow onion
Glycine soja Soybean
Jycopersicon esculentum Common Tomato
Phaseolus limensis Lima Bean
vulgaris humilis Bush Bean
Spinacia oleracea Spinach


Alyssum. saxatile citrinum Goldentuft Alyssum
Fragaria op. Strawberry
Gaillardia sp. Gaillardia
Lobelia op. Lobelia
Scabiosa op. Scabious

22 3 1262 09239 1365

There is some evidence that the detrimental effect of technical
_.iDT in the soil on some plants is not caused by the compound, but by impurities and certain isomers in the technical material. Bush beans, lima beans, and tomatoes did not tolerate 25 pounds per acre of the technicalDDT but grow normally in soil containing 200 pounds of purified DDT per acre.

Effect of DDT on Warm-blooded Animals

In the experimental work with DDT for control of the Japanese beetle., some birds,, principally robins and catbirds, were killed, probably by feeding on poisoned insects. When DDT was applied as a dust to the ground, it was urged that horses, cows, goats, chickens, ducks,, and other animals be excluded from the treated area until rain had removed most of the dust fro a the foliage. No harm to stock was observed when this procedure was followed, but much more information is desired on the reactions of various animals after feeding on plants treated with DDT*

Residue of MT on Food Crops

Fruit picked immediately after being sprayed with water-dispersible DDT, 1 pound per 100 gallons, with summer-oil emulsion added as a sticker, had a residue of more than 7 mg, per kilogram, Apples picked 6 days after spraying and passed through a wiper had a residue which approached this amount; apples picked 2 weeks after spraying and wiped in the same manner had a residue well below this. Peaches picked 2 weeks after spraying and passed through a "defuzzsr" had a residue less than 7 mg. per kilogram* When more than one application of this spray was made to peaches and grapes during the summer, the residue on the fruit at harvest was definitely above
7 mg. per kilogram.

When the sticker was omitted, apples picked 3 weeks after one application of the spray had a residue of 2.5 mg. per kilogram, and peaches picked 3 to 4 weeks after spraying had 4,7 to 6 mg. per kilogram. Grapes sprayed three times with 1 pound of waterdispersible DDT and once with 1/2 pound of the material per 100 gallons had a residue of 3.8 mg. per kilogram at harvest,