June 19h47 LIBRARY E-727
STATE PLANT BOARD
United States Department of Agriculture
Agricultural Research Administration
Bureau of Entomology and Plant Quarantine
CONTROLLING THE JAPANESE BEETLE
By 0. H. Hadley
Division of Fruit Insect Investigations
The Japanese beetle (Popillia Japonica Newm.) feeds on the leaves,
and sometimes on the blossoms and fruit, of many kinds of trees, shrubs,
and farm crops, and on the roots of grasses and other plants. It is
native to Japan, and was accidentally introduced into the United States
in New Jersey some time prior to 1916. Since that time the infestation
has increased and spread, so that it now occurs in all States east of
and including Ohio, West iirginia, Virginia, and North Carolina. However,
the infestation is much more general and continuous along the Atlantic
seaboard than in the States to the westward.
HOW TO BRECOGNIZ THE JAPANESE BEETLE
The adult Japanese beetle is nearly half an inch long, about one-
fourth inch wide, broadly oval, and shining metallic green. The hard
outer wings are coppery brown. There are two small tufts of white hairs
Just behind the wing covers and five patches along each side of the body,
which make the Japanese beetle readily distinguishable from other beetles.
The newly hatched larva, or grub, is about one-sixteenth inch long,
has three pairs of legs, and has the general shape of a blunt-ended
crescent. When fully grown it is about an inch long and resembles the
white grubs, or grubworms..
The Japanese beetle normally requires one year to pass through all
stages of its development. In the latitude of Philadelphia the beetles
usually begin to emerge from the soil between June 10 and 20, and they
are present in considerable numbers by July 5. The feeding season reaches
a peak the last of July or the early part of August. The normal life of
a beetle is from 30 to 45 days, but a few may be found as late as October.
At more southern points beetles are active earlier in the season; farther
north they appear later.
On warm, sunny days the beetles fly about from one plant to another.
They tend to collect in groups and to feed. on certain plants, leaving
others, apparently equally attractive, untouched. From time to time they
burrow into the ground to a depth of 2 to 4 inches, where they lay eggs.
For this purpose the beetles prefer medium-moist, loamy soil with closely
JUL 3- 1947
cropped grass, such as is found in lawns, pastures, and golf greens and
fairways, but some eggs are always placed in less favorable situations,
such as flower beds and cultivated ground. Each female lays from 40 to
The eggs hatch about 2 we ter are laid, and the young grubs
feed on the roots of grasses other ts. TL grub stage continues
through the fall and winter a.i.: until the 'iter part of MW or early in
June of the following year. In the s e and e.-rly fall the larvae feed
mostly in the upper 3 inches of the eol, A as winter approaches they
go down to a depth of 3 to 6 inches, :n,'. nearer to the surface the
FEEDING HABITS T-' F-7 T .."S OF : BE ETLE
The beetles feed chiefly on the !c es on the upper and outer parts
of plants and trees exposed to bri-t I..-lht, during the warmer part of
the day. On cloudy or cool dA7 th i s almost no feeding. The beetles
eat the tissue between the veins of the leaves, causing the leaves to
become skeletonized. Leaves that have been thus injured soon turn brown
and fall, and as a result pr-:-err -d food plants in heavily infested areas
are often entirely stripped of their fo-Iage. When the infestation is
very severe, even large fruit and sh,: tLrees may be completely defoliated
within a few days.
The Japanese beetle is knon to feed on more than 275 different
plants, but most of the injury ia conflj.id to comparatively few of the
more favored species. The beetle is -ai important pest on early-ripening
fruits, especially apples, peaches, n-d p2lws, The beetles often con-
gregate in masses on the fruit and eat until only the core, stone, or pit
is left. Prematurely ripened or e-icect fruits are preferred, but where
the infestation is heavy, nearly all the fr-uit may be injured. Late varie-
ties of fruits usually escape attac
Beetles also cause much inj!,, to flela and sweet corn by feeding on
the silk as it grows out from tb h 'uk *"fore pollination takes place.
The destruction of the green, iat silk p events pollination and sub-
sequent development of the kernels ','*g field crops other than corn,
soybean and red clover are most like I" to be severely attacked. Asparagus,
rhubarb, and beans are subject to attack, but most of the other common
vegetables are rarely injured,
FEEDING AB "'.] T.HE LRVA
The grubs of the Japanese beetle fr:1vmntly cause severe injury to
turf in lawns, golf courses, paria, and -iastures, As they burrow through
the soil, the grubs cut and feedi o the rootlets of grass, causing it to
die out in small Datches or lagor 'eao Trf killed in this manner can
be rolled back easily, disclose the u ''-e beneath. Considerable injury
is also caused at times by the grubs feeding on the roots of strawberry
and corn, bean, tomato, beet, oni,", ind other vegetables, and ornamentals,
such as iris, peony, gladiolus, -i rpji- gon.
CONTROLLING THE ADIT BIEETLE
Sprays containing DDT, lead arsenate, rotenone, and a lime-aluminum
sulfate combination have been used successfully for protecting foliage
and fruit from beetle attack, although no material has been foudJ entii'rly
satisfactory for protecting flowers highly attractive to the beetle. The
DDT spray ia preferred, as it kills rather than repels the beetles, is
cheap, and leaves an inconspicuous residue that usually protects the foliage
for several weeks. The lead arsenate spray is also effective for a long
period, but it acts chiefly as a repellent and leaves a conspicuous deposit
which under some conditions may be objectionable. The other sprays are
suzgested where the use of DIDT or lead arsenate is likely to leave harm-
ful residues on fruits and vegetables.
Timeliness and thoroughness in the application of sprays are very
important. As a general rule, especially in localities where the beetles
are very numerous, the first spray should be applied when the beetles are
first seen, before they become established on the plants. In heavily in-
fested localities it is often difficult to prevent injury if the spraying
is delayed until beetles appear on the plants. Where the infestation is
not dense, the first application may be delayed until the beetles begin
to concentrate on the plants to be protected.
DDT Sprays and Dusts
Fruit and ornamental trees and shrubs may be protected by spraying
or dusting them with DDT. The spray is prepared by mixing 2 pounds of a
wettable powder containing 50 percent of DDT in 100 gallons of water. For
smaller quantities use 3 ounces (16 tablespoonfuls) of the 50-percent DDT
powder in 10 gallons of water or 4 teaspoonfuls per gallon. If a wettable
powder containing a different percentage of DDT is used, the quantities
,should be adj-usted accordingly. The DDT may be used alone or in combina-
tion with a fungicide, such as wettable sulfur.
One application of the spray is usually sufficient to ,d.tect the
fruit and foliage of many fruit trees. A second application ; or 5 weeks
later may be required on ornamental trees and shrubs and on grapevines, to
protect new growth. When a second application to grapes is necessa-v7,
only half the mount used in the first spray should be used.
Dusts containing 5 to 10 percent of DDT have been used with se
success, but they are less effective than the DDT sprays. DDT sh:.ould, not
be used on fruit that is about to ripen; other spres, discussed later,
are preferable. DDT sometimes causes various species of mites to Increase
in abundance, probably by destroying their natural enemies.
Lead Arsenate Spray
The foliage of fruit trees of late-ripening varieties and orn.uental
trees and shrubs may be protected by sprayiia; with lead arsenate. ^is
spray is prepared by mixing lead arsenate and common wheat flour in the
For 100 gallons For 10 gallons For 1 gallon
Lead arsenate . 6 pounds 10 ounces 1 ounce
(4 1/2 tablespoonfuls)
Wheat flour . 4 pounds 6 ounces 0.6 ounce
Other stickers, such as raw linseed oil or fish oil, may be substituted
for the flour at the rate of 4 fluid ounces to each pound of lead arsenate.
The lead arsenate spray for Japanese beetle control is not advised for use
on early fruits, ripening in July or August.
PRECAUTIONS IN USING LEAD ARSENATE OK DDT.-Lead arsenate is poisonous
to man and animals. In handling it one should take care to avoid inhaling
the dust. It should be kept in plainly labeled closed containers away from
food products, and where children or pets cannot reach it. Since it is
possible that the poison may be absorbed into the system through cuts and
scratches on the skin, it is advisable to protect the hands. The worker
should keep his hands away from his mouth and wash them thoroughly before
Children and domestic animals should be kept from playing or feeding
on the poisoned turf until it has been watered or rain has fallen. The
extensive use of lead arsenate on lawns within the heavily infested area
has not caused any known damage to poultry or native birds that feed on
earthworms and grubs in the soil.
Similar precautions should be observed in handling DDT.
The following sprays have been used successfully to protect fruits
and vegetables that cannot be treated with DDT or lead arsenate:
Lime-Aluminum Sulfate Spray
For 10 gallons For 100 gallons For 1 gallon
Hydrated lime (for spraying). 2 pounds 20 pounds 1 measuring cup
Aluminum sulfate ....... .1/2 pound 3 pounds 2 tablespoonfuls
Dissolve the aluminum sulfate in about 1 quart of water (or 2 gal.
when preparing 100 gal. of spray) and add it to the partly filled spray
tank while the agitator is in motion or with frequent stirring. Then make
a thin paste of the lime and wash it through a screen (to remove lumps)
into the spray tank before adding the remainder of the water.
S.] .,100 gaIlousI For 1 gal lon
T br one-
-I *.on o 5 ounces 3 pounds 1/2 ounce
As the . .:..'': ,: .. : derris, cube, or timbo may be used,
prove! ,c- the ei 1o...:_. i.. less tha 4 percent of rotenone and not
e .; 16 .. .;'.t .,. tot.-i xt..it-i db.; The rosin emulsion can usually
be obt_.:- I.. the :-t..lsifid foam from insecticide dealers.
To 3:,. : the _.' wash h rosin emulsion into the partly filled
.'.. tank e t ..',-.'.. material into a thin paste with water and
wah it into '- L with the
before a ddii-- r..-..idc'. of the water,
.,ts r, .. at the h:i.-t of the beetle season are the most severe-
ly at: ..cr.,'. -i -..,.t ..c..]t to protect. To avoid harmful residues
S_ dii nt ed '..'i L'. fruit trees later than 2 weeks, and lead
.e not 5& 3 to 4". before harvest. The lime-aluminum
sl.'.:: spr .e en ed with satisfactory results for the protection
of ear" ... fo pe,. -., ne,-t7.eines, and plums the rotenone spray is
preferable It is -." .t :h' the protective covering on the trees be
Lf-.$uate to over the natural attractiveness of the fruit. Fruit ripen-
in" after 1.e hei.ut of the beetle season is seldom eaten by the Japanese
beetle, insecticides are sometimes necessary to protect the foliage.
DDT may be us-" n suc a r.: if ap.plieda no later than 3 or 4 weeks be-
Teither DDT nor arsenate should be used on raspberry, black-
berry, an6, blueberry bushes until after the fruit has been harvested.
Appl '.-' ion of the tencne will afford some protection, depending
on the beetle ,"'on ripeness- the fruit, and weather conditions.
O..' a few the v.-et- les are seriously injured by
the beetles. .-st -'- bsefw .a be protected by spraying or dusting
with DDT When porions of the -I:.t that are soon to be eaten are ex-
posed to the aT:-a", as in the case ,3 ring beans, DDT should not be used.
Th3 nonpoisonous lime-aluTinum ,-[ate spray should be used instead.
Vegetables in home -.... c be giv-.. s'mae protection by dusting with a
good ...: of fine -,rated lime.
Corn ma,-r be -.otected by arplying, to the silk, a dust containing 5
to 10 percent : .'Hoever, if the corn fodder is to be fed to live-
stock, DDT should not be used; hydrated1 lime ispreferable.
Roses are c -. L w.T -ible to attack and are difficult to rro-
tect. "-, most o-,t cal me .- is to dis-:id thpm durirL the period of
beetle flight, a --.-, tect the leaves by sprsN'ini- with DDT or lead arsenate
.J Sion Z^.i.4 4Ay
as already discussed. It has been found that plants treated in this
manner will thereafter have a profusion of blooms of excellent quality,
and will bloom later than if allowed to flower throughout the summer.
Choice rose and other ornamental plants may be protected from beetle
attack by enclosin? them with a cloth or wire netting on a wooden or
metal frame. When roses are protected in this manner, it may be neces-
sary to apply a fungicide during July and August to prevent mildew.
CONrROLLING GRUBS IN LAWNS A)D OTHER TUBRF AREAS
It is possible to make an established lawn practically immune to
injury by grubs of the Japanese beetle by applying DDT or lead arsenate.
These materials can be applied at any season when the ground is not
frozen, but the best results are obtained if the application is made in
the spring. The treatment of pasture land is not recommended.
For treating lawns or other small turf areas, the DDT should be applied
to the surface as uniformly as possible, as a 10-percent DDT powder at the
rate of 6 pounds per 1,000 square feet. It may be broadcast by hand or
with a small fertilizer distributor.
Lead arsenate may also be used, at the rate of 10 pounds of lead
arsenate powder per 1,000 square feet. The powder may be mixed with
several times its volume of moist sand, soil, or other suitable material,
and applied in the same manner as DDT.
After application of either the DDT or lead arsenate, the lawn
should be well watered with a hose to wash the poison into the soil.
Larger turf areas, such as estates, parks, golf courses, or ceme
teries, can be treated more economically by means of a large fertilizer
distributor. The DDT should be used at the rate of 250 pounds of 10-per-
cent dust per acre, the lead arsenate at the rate of 435 pounds per acre.
Where spraying equipment is available, a wettable DDT powder may be used,
at the rate of 100 pounds of 25-percent, or 50 pounds of 50-percent DDT
powder in 1,000 gallons of water per acre, which is equivalent to approxi-
mately 23 gallons per 1,000 square feet of turf. Lead arsenate should be
used at the rate of 435 pounds suspended in 1,000 gallons of water per acre.
Like human beings, the Japanese beetle is subject to disease. The
most important one that kills many grubs is known as the milky disease,
caused by tiny germs, or bacteria. In a diseased grub the blood, usually
clear, assumes a milky color.
The milky-disease germs, or spores, live in the soil for long periods,
ready to infect and kill successive broods of Japanese beetle grubs as
they move about in the soil, feeding on plant roots. Fortunately, the
disease is harmless to human beings, warm-blooded animals, and plants.
Workers in the Department of Agriculture have invented devices and
methods by which inoculated grubs are used for the production of spores
of the milky-disease organism in the laboratory. The grubs, after being
thus infected, are ground and mixed with talc to form a "spore dust"
mixture, which can be applied to turf and other grass areas to destroy
the grubs. The spore dust is available commercially with directions for
its use, and may be applied by individuals, or preferably by community
groups, to control the grubs in the soil. The disease usually works
slowly, and it may be several years before its full effect is evident.
If there are nearby sources of infestation, tho use of the disease in a
small area will not keep the beetles from flying in from outside and
causing serious damage to trees and shrubs.
UNIVERSITY OF FLORIDA
3 1262 09227 9982