The use of methyl bromide for the treatment of quarantined plant products

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Title:
The use of methyl bromide for the treatment of quarantined plant products
Physical Description:
6 p. : ; 27 cm.
Language:
English
Creator:
Hawkins, Lon A ( Lon Adrian ), 1880-
United States -- Bureau of Entomology and Plant Quarantine. -- Division of control investigations
Publisher:
U.S. Dept. of Agriculture, Bureau of Entomology and Plant Quarantine
Place of Publication:
Washington
Publication Date:

Subjects

Subjects / Keywords:
Bromomethane   ( lcsh )
Fumigation   ( lcsh )
Insect pests -- Control   ( lcsh )
Bromomethane   ( fast )
Fumigation   ( fast )
Insect pests -- Control   ( fast )
Genre:
federal government publication   ( marcgt )
non-fiction   ( marcgt )

Notes

Statement of Responsibility:
by Lon A. Hawkins.
General Note:
"E-484 July 1939."
General Note:
Caption title.
General Note:
"This paper was presented at the meeting of the Central States Plant Board at St. Paul, Minnesota, on March 22, 1939."

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
oclc - 607575557
ocn607575557
System ID:
AA00023511:00001


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Full Text



E-484 July l'z9

United Stares Depart: me-rt of Agricult'arO
Eureau of Entomology and Pl11jt Quarantine


THE USE OF METHYL BROMIDE FOF.R THE TF'E'.T;,..E:T OF QUAFAi,;Ir ED PLANT PRODUCTS/

By Lon A. Havkii.s, Division of Control Investigations




As a treatment for living hosts infested with insect pests under quar-
antine regulations, :'un.,gation with methyl bromide in many cases meets the
requirements for an effective treatment which is nor'.i'jurious to the host for
the purpose for vhich it is inte.-,-ed.

Methyl bromide is a gas at ordinary temperatures, its boiling point
being 40.1 F. As a liquid it has a specific gravity of 1.732 and as a gas
it is approximately 3.5 times as heavy as air. As c,'-,r.ir.ercially produced,
methyl bromide is approximately 99.5 99.8 percent pure. It is soluble in
most common organic solvents but is only very slightly soluble in water. In
an impure state it is used in fire extinguishers in France and England.

The first use of methyl bromide in insect control was made in France,
about 19J2., when it was applied as a blanketing gas with ethylene oxide. As
there were indications of its insecticidal value, hov.ever, it was then tested
as a fumigant alone. Its first recorded use in this country against insects
was by D. B. Mackie in 1975. Mackie carried on considerable work with it,
both of an experimental and of a practical nature. He has shown that numerous
fruits and vegetables and other commodities can be fumigated with methyl
bromide with safety, and he has also used it for killing rodents and termites
in California. Sc.;:e of his r.'e'.'ts are given in his several publications on
the subject.

Methyl bromide was used experiLeentally by this Bureau in the summer of
1936 in the fumigation of fruits and vegetables for the adult Japanese beetle.
and the results obtained in this investigation indicated that it might be
valuable against other insects affecting fruits, vegetables, and nursery stock.
Since that time work has been taken up on the destruction of insects which are
under quarantines, both Federal and State, on a number of plant products. This
work has been carried on by A. C. Johnson, E. 1.1. Livingstone, H. C. Donohoe,
J. '. Bulger, Pa..dall Latta, S. S. Easter, and H. H. RichardsoL,, of the Divi-
sion of Control Ivestigations, but most of it has been in cooperation with
other divisions of the Eureau of L:tocolc-! and Plant Quarantine, various

I/ This paper was presented at the mee-ii.i of the Central States Plant
Board at St. Paul, M.i.esrta, on a'ch 22, 1939.







-2-


State departments of agriculture, shippers, railroads, nursery men, and
others. The list of collaborators is too long for mention to be made of each,
but the excellent cooperation received has contributed markedly to the success
of the work. It is very much appreciated.

In cooperation with the divisions of this Bureau concerned, experimenta-
tion has been under way since 1936 on adults and larvae of the Japanese beetle,
in developing a treatment for fumigating carloads of fruits and vegetables in
the regulated area -o that they can be shipped outside that area without
danger of carrying live adult beetles, and in the treatment of nursery stock
so that it will be freed of any infestation by adults or larvae. It was deter-
mined that in green string beans, white potatoes, northern-grown sweetpotatoes,
lima beans, sweet corn, peppers, tomatoes, and a number of other types of green
vegetables and fruits shipped in the living condition, the fumigant could be
applied at a dosage sufficient to kill the beetles in the package without
damage to the commodity. This investigation has been extended since its incep-
tion, and during the past summer, in cooperation with the various interested
agencies, a method was developed for fumigation of produce in refrigerator
cars for the adult Japanese beetle.

The method employed in truck-growing regions of New Jersey, Delaware,
Maryland, and Virginia in 1937 to insure freedom from infestation of shipments
of such commodities during the Japanese beetle flight period was to prefumigate
refrigerator cars for fruit and vegetable shipment, screen them, and then
free the fruits and vegetables from beetles by other methods before loading
them. This involved fumigating and screening some 15,000 cars at considerable
cost, whereas only about 4,000 of them moved out of the regulated area. It
was decided that it might be practical to fumigate and screen only the loaded
cars that were to be shipped out of the regulated area, eliminating the cost
of prefumigation and screening in other cases. The cars destined for un-
infested territory were therefore fumigated at diversion points and allowed to
move from the shipping point possibly a day's run to this point without screens.
In this way fumigation was localized and all was done at three points. The
cars traveled under ventilation in the usual manner to the particular diversion
point and were fumigated after the contents had been sold. In this work some
2,771 cars were fumigated during the past season. The dosage was 2 pounds
per 1,000 cubic feet, or 5 pounds per refrigerator car having a capacity,
including ice bunkers, of 2,500 cubic feet, and it was applied at a temperature
of 70 F. or above. The fumigant was agitated by a blower for part of the
time the fumigation was in progress -- sufficiently to mix it thoroughly with
the air in the car. Tests of the efficacy of the method were made by arti-
ficially infesting 16 cars with approximately 45,000 Japanese beetles. There
were no survivals afte: fumigation.

In connection with this work, one point which deserves consideration is
the retention of methyl bromide by fumigated products. A cooperative project
with the Public Health Service has beer. under way for the last year and a half
:i the amount of methyl bromide retained by fumigated plant products and the
effectt of ingestion of these products by warm-blooded animals. H. C. Dudley,




- 3 -


of the Fiblic '-cal.th Service, has been carrying on this study and presented
a Farer on his work at the Richmond meetings. In general it has been found
that only a small aniou:it of methyl bromide is retained by most fumigated plant
rrodLicts tested -- cci.biderably less than would be dangerous for ingestion.

A meihod of fumigating stra'.Wberry plants in field baskets, or packed
ir. crates, for Japanese beetle larvae was worked out on a commercial basis
aTd authorized. A fumigation room with apparatus for circulating the air-
gas mixture throg'..ihn..-t the room was developed, built, tested, ad found
satisfactory.

Extensive investigations on fumigation of nursery stock for Japanese
beetle larvae, in which scre 4,000 plants of 575 varieties, representing ap-
proximately 2C0 genera, were used, with a total of around 20,000 larvae of
the Japa.ese beetle, show that complete mortality of the larvae can be ob-
*a-:'.ed by fumigating at a 3osage of 2-1/2 pounds of methyl bromide for a
period of 2-1/2 hours, at temperatures of 63 F., or above. The treatment so
far is limited to 8-inch pots or soil balls, but investigational work is under
way on larger soil masses, in the hope of extending the treatment to the
general run of balled and burlapped stcck.

It is of interest to note that this treatment has been applied to 25
varieties of hydrangeas with no damage and in most cases a noticeable accel-
eration of gro.,,th. Ninety-two varieties of azaleas have been treated and
only two of these have shown definite injury. This treatment has been
authorize-, and shipments of fumigated plants are being n:a:ie at the present
time,

Oriental Fruit Moth

.'.'rk with the oriental fruit moth, taken up at the suggestion of J.
Carl Ea;,son, State entomologist of Missouri, in 1936, when a few small lots
of peafh nursery stock in which hibernating larvae had been placed were fumi-
ga.ed-, was continued during the winter of 1936-37 with approxif-ately 25,000
hibern-ating larvae of this insect. The larvae were in cocoons in corrugated
paper, or had spun cocoors among twigs or in holes in small branches pre-
Fared for that purpose.

In carrying out this project it was necessary to design a fumiga-
tion box that was ti-ht and that could be heated readily and brought up to a
fairly, constant temperature. Such a box was built of galvanized iron, in-
sulated ani equipped with a fan for mixing the methyl bromide with the air and
on electric heater thermontati-ally controlled, The box was self-contained
in that it was only necessary to plug it in in a light circuit to make it
ready for use.

In the exFerimen-al work the cocooned insects were placed in among
i:rush in the box in as r.early natural conditions as possible, and after fumi-
gotion mxst of the insects were placed at outside temperatures for a period
to simulate natural conditions. Dosages of from 1 to 4 poun'is were used, and
it -,,.as found that 3-1/2 and 4 pounds of methyl bromide per 1,000 c'ibic feet





-4-


for a period of 4 hours gave a complete kill in all cases. Some 50 experi-
ments were carried out with this treatment and there was'indication that a
lower dosage might be employed.

The process was tested out on nursery stock in connection with three
commercial nurseries, one in Missouri and two in Maryland. In the tests in
.issouri 26 varieties of nursery stock -- in all about 1,000 trees -- were
treated. The dosages were 3 pounds for 5 hours, 3-1/2 pounds for 4 hours,
and 4 pounds for 4 hours at approximately 70 F. The stock was stored and
planted out with an equal number of checks that had not been fumigated, to
determine the comparative effect of the fumigant on the trees. Somewhat
similar experiments were carried on in Maryland. The plantings were inspect-
ed at intervals throughout the summer. In most cases there was apparently no
effect that could be attributed to the fumigant. In some cases there was a
stimulation of growth and in a few instances a retardation, the latter oc-
curring particularly in some varieties of apples. There was less damage to
apples at the lower dosage of 3-1/2 pounds than at 4 pounds, although in some
cases a definite retardation of the rate of growth was noted in the fumigated
trees, even at the lower dosage. The work is being continued during the
present season with a probability that a lower dosage may be effective and
possibly a lower temperature. As a result of the work so far, seven of the
Western States have modified their State quarantines to admit nursery stock
from infested areas when fumigated by this method, and stock is being treat-
ed and shipped commercially into these States.

SweetpotatQ Weevil

In connection with the eradication of the sweetpotato weevil, experi-
ments were begun in the summer of 1937 in devising a method for destroying
the sweetpotato weevil in seed potatoes, and with the further idea of de-
veloping a method of treating potatoes for culinary purposes so that they
could be shipped outside the regulated area with no danger of carrying the
insect. This involved determining the time and dosage necessary at various
temperatures to kill all stages of the insect on and within the sweetpotato
and sweetpotato plants. This was done for several temperatures and complete
mortality was attained at 70 F. and above with a dosage of 3-1/2 pounds
per 1,000 cubic feet and an exposure of 4 hours. It was found rather easy
to kill the weevil within the sweetpotato, but the effect on the host
was rather disturbing. When sweetpotatoes were taken from the kiln where
they were maintained at a temperature of around 50 F. and fumigated at
these low temperatures, even when the dosage was only 10 ounces per 1,000
cubic feet, they were liable to break down. In some sizable experiments,
involving on the whole a hundred bushels or more of sweetpotatoes, practical-
ly a complete breakdown occurred in the treated potatoes and only a slight
deterioration in the control. It was found, however, that by raising the
temperature of the sweetpotatoes to above 70o F. a few days before fumiga-
tion, treating them at this temperature, and then holding them for 2 or 3
days before bedding, this difficulty could be largely obviated. Two sizable
experiments were carried on last year on a commercial basis with excellent
results in that the fumigated potatoes produced an excellent crop of drav'3.
Treatment with methyl bromide markedly a( ilerates the production of shoots





- 5 -


and new growth in sweetpotatoes. Approximately 2,000 bushels have been
ful--gated and planted this year in cooperation with '10 or 50 gi-ro'Aers, with
a view of getting the prccG-s on a commercial basis, and ironing out any
flaws in the procedure.

White-fringed Beetle

Investigations have shown that methyl bromide can be used in the
fumigation of potted plants and greenhouse stock for the white-fringed
beetle. A method has been developed for fumigating this stock at atmos-
pheric pressures and at a temperature of 85 F. with a dosage of 1 pound
of i~ethyl bromide per 1,000 cubic feet. Out of 33 plants, mainly herbaceous
perennials, some 24 can be fuinigatcd without injury. Treatment of potting
soil with a dosage of 40 cc per cubic yard gave a complete kill of the
larvae of this insect at a cost of approximately 10 cents per cubic yard.

Fumigation of Miscellaneous Imported Plant Products

Experiments are undr way in developing treatment for imported
plant products, and this work so far is largely concerned with determining
the effect of the fumi :.;.t on the numerous plants and plant products that
are inrported into this country in commercial quantities. It is planned to
test the effect on the insect when sufficient numbers are available in
comnircial s-hipT.ents of infested stock. When the effect on the host plant
of fairly heavy dosages is known, the work can be completed rapidly when a
sufficiently heavy infestation is found to furnish material for determining
the effect on the insect.

In fumigation with methyl bromide, most of the evergreen plants
and rose stocks, and nursery stock of such types, can be treated at a
reasonably high dosage without injury to the plants. Some injury has been
obtained with cacti and succulent plants. A number of experiments with
Cattleya orchids which were infested with a coleopterous leaf miner were
carried out during the past season, and complete mortality of the leaf
miner was obtained by fumigation under 15-inch vacuum at a dosage of 3
pcur.ds per 1,000 cubic feet, the orchids being in a dry condition. There
was little or no injury to the orchids. Cipollini bulbs recently shipped
from Morocco to New.' York were found infested with larvae of Excsoma lusi-
tanica, a chrysomelid beetle not known to exist in this country, and it
was possible to obtain some information on the effect of fumigation on both
bulbs and insects. These bulbs were in dormant condition, and fumip-ation
at a concentration of 4 pourds per 1,000 cubic feet in 15-inch vacuum for
2 hours did not injure them and killed all the larvae that were found on
later inspection. About a thousand cv.eo of these bulbs were fumigated.

Similar work in connection with saipn.ents of green lima beans from
Cuba, infested with Mru.:a lstulalis, one of the bean pod borers, was carried
out. Shipments arriving in N..' York were fumigated with a concentration of
4 pounds of methyl bromide per 1,000 cubic feet in a 15-inch v.,cuu,.i for a




UNIVERSITY OF FLORIDA

3 1262 08537 0962

6 -

period of 4 hours. Complete kill of the insects found in the pods has been
obtained in a total of several thousand hampers. No injury to the lima beans
was evident. The fumigation has been successful even at temperatures around
40 F. These results are being checked in Puerto Rico, where this insect
is abundant, and sufficient data should soon be available for definite recom-
mendations as to the treatment.

Studies are under way on the treatment of scale insects and certain
other insect pests.

In general, methyl bromide seems to be specially adapted to the
fumigation of plants or plant products which are transported and marketed
in a living condition. It does not appear probable that it will take the
place of other fumigants as an all-purpose fumigant but rather that it will
extend the field for gaseous insecticides. It injures some plants and may
accelerate or retard the growth of others. It appears to be a distinct ad-
dition to the means of combating insect pests, especially as a quarantine
treatment.




Full Text
BRARY
PLANT BOARD
Z-484 July 1939

United States Department of Agriculture
Bureau of Entomology and Plant Quarantine


OF METKW:DRW1DE FOR THE TREATMENT OF QUARANTINED PLANT PRODUCTSI/

By Lou A. Hawkins, Division of Control Investigations
lu g ... ..

tp
living hosts infested with insect pests under quar-
ftolatiOns, Pumigation with methyl bromide in many cases meets the
tO for an effdotive1reatment which is noninjurious to the host for
.F*r*Whi0Wit is intended.

2bromide i a gas at ordinary temperatures, its boiling point
As a liquid it has a specific gravity of 1.732 and as a gas
dkim6tely..5-3.5 times as heavy as air As commercially produced,
ide is approximately :99.5 99.8 percent pure. It is soluble in
ftorganic solvents but is only very slightly soluble in water. In

""ate it is used in fire extinguishers in France and England.
fittt::.:use of:methyl bromide in insect control was made in France,
;,_wh6rd it was applied as a blanketing gas with ethylene oxide. As
ftAidioations. of its insecticidal value, however, it was then tested
#Wtg#kt -alone. : Its first recorded use in this country against insects
W11. Mackie in 1935. Mackie carried on considerable work with it,
4 i,*kp6rizental and of a practical nature. He has shown that numerous
Afid lvegetables and other commodities can be fumigated with methyl
Vto S....ft kty ,and he has also used 'it for killing rodents and termites
ia. Some of his results are given in his several publications on
01K.
TV
*iw bromide was-us0d.experimentally by this Bureau in the summer of
rukligatiot of fruits add vegetables for the adult Japanese beetle,
result$ obtained: in this investigation indicated that it might be
*,,against 'other insects affecting fruits, vegetables, and nursery stock.
t tive'work has been taken up on the destruction of insects which are
rantines, both Federal and. State, on a number of plant products. This
b*eticarriod'an by A. C. Johnson, E. 9. Livingstone-, H. C. Donohoe,
%*ro Randidl Latta'i S. S. F-aster-,.and H. H. Richardson, of the Divi-
1101001rdl lnv Wt igat ions, butmost of it has been in cooperation with
dtf"Ake Bureau: of Entomology and Plant Quarantine, various

4/This paper was presented at the meeting of the Central States Plant
*V3_ or Poul., Minnesota, on March 22, 1939.















treated. T
and 4 pound
planted out









State departments of agricultu i
others. The list of collaboratore stoln o eto ob aeo ah
but thle excellent cooperation reevdhscnrbtd akdyt h ucs
of the work. It is very m at

In cooperation with the dv
tion has been under waye sinoe
in developing a treatment fr le
the regulated area Eo tt t
danger of carrying lvl
so that it will be freed
mined that in greenea pstris
lima beans, sweet corn, peppers,toaosananubrfohetysofge-
vegetables and fruits shipe ntelvn odto' h uiatcudb
applied at a dosage sufficient damge to the commodity. tion, and during the pat smei oprtoihtevrositrse
agencies, a method was
cars for the adult Japaesebet.

The method employed i
Maryland, a Virginia in1 in
of such commdities during the Japns etefih eidwst rfmgt
refrigerator ars for frt t
free the fruits and veealsfo ete yohrmtosbfrodn
them. This involved fumigati
cost, whereas only about 4,00o hem oeu ftergltdae.I
was decided that it mightbepatcltfuiaeadsrnolyheodd
cars that were tohbe shpe otoftergledaalintnghecs
of prefumigation and screenn in ohrcss h asdsie o n
infested territory were thereforefmgtda ieso onsadalwdt
move from the shipping on osbyadysrnt hspitwtotsres
In this wyfmgto a oaie n l a oea he ons h
cars traveled under yentlto inteuulmneiotepriua ieso
point and were fmgtdatthcotnshdbnsl.Inhiwrkom
2,771 cars werefuiaeduigtepssesnThdoaews2ons
per 1,000 cubic feet, or onsprrfieaorcrhvn.a-aaiy
including icebukro2,0cuifetanitwsapidaatmeaue
of 700 F' or aoe h uiatwsaiae yaboe o ato h

the air in the car.Tetofteefccoftemtowread yti




the retention ofthy brmdtyfmgtdpoucs oprtv rjc
with the Public elhSriehsbe newyfrtels eradahl
Dnteaon fmty rmd eane yfmgtdpatpout n h
afec of ineto ofj thes product bywrmbode nmas .D le









period of 4 hours. Cmlete kilo th A obtained in a total of several thousand hampers oijr otelm en
was evident. The fumigationhabenscesuevnttmpruesrod
400 F. These results are being cekdin Pet io hr hsisc
is abundant, and sufficient data shudso0eaalbl o eiiercm
mendat ions as to the treatment.

Studies are underwaontetetetosclincsadcran
other insect pests.

In gnera, methyl broiesest eseilyaatdt h
fumigation of plants or plantprdcswihaetnpoedndmktd
in a living condition. It does not aperroalthtiwllak o
place of other fumigants as an all-proefmgn u ahrta twl
extend the field for gases inseticids. I nue oepat n
accelerate or retard the growth of othrs. It apast eadsic d
dition to the means of combating inscpetseialasaqrnio
treatment.
iiii i~iiiiii~ i~~ii 'ii i i .. M

tu 4









, 'n o rwhi weptte. Aprxmtl ,0 uhl aebe
ftii aedan panedthsieaiiicoertiniiti4io 5 gowrsiwt

4 iewo etn hiioesoi omeca aiad rnn u n
f !w ntepoeue


Whie-fingdiBitl
I nvstgaiosiavisowitatmehyibomiecaibiuedinth
==igi on o potedplats nd reehous stck or he hit-frng
tJe Ameho hs ee dveopd or umgain tisstckatatos
........... prsuesadatatmprtreo 50F it osg f on
iiiiiiiier100cui ee. Ot f3 pans ail eraeu
is soe2 ca befmgtdwtotijr.Tetetopotn
itr t tii u i th doag o 4iccpeiiuicyar gae coplte il of th

-- ofthsinec t csIo apoxmtey 0cetspr ubcyad








Fumigation............. ofMselnosIpotdPatPout
Experiment ar une wayinideelopng teatmnt frimorte
ou rdcs adtiioksofri aglyiocreiit eemnn
effec of~i]i th..... ntenmeospat adpatprdcsta
a importd int thi counry incommrcialquantties It i planed t
at. the effctonth ineciwensuficeninmbrsareavilbii





fto 3 -

at the Public Health Service, has been carrying on this study and presented
kp":.r on his work at the Richmond meetings. In general it has been found
that only a small amount of methyl bromide is retained by most fumigated plant
products tested considerably less than would be dangerous for ingestion.
4 f n :.
,1 ..' : A method of fumigating strawberry plants in field baskets, or packed
44 arates, for Japanese beetle larvae was worked out on a commercial basis
,*dauthorized. A fumigation room with apparatus for circulating the air-
Vg mixture throughout. the room was developed, built, tested, and found


Extensive investigations on fumigation of nursery stock for Japanese
booltlw larvae, in which some 4,000 plants of 575 varietiesP representing ap-
jvtmately 200 genera, were used, with a total of around 20,000 larvae of
U# Japauese beetle, show that complete mortality of the larvae can be ob-
4Aiwd by fumigating at a dosage of 2-1/2 pounds of methyl bromide for a
por*qd of 2-1/2 hours, at temperatures of 630 F. or above. The treatment so
Ur-mis limited to 8-inch pots or soil balls, but investigational work is under
$,*y on: larger soil masses, in the hope of extending the treatment to the
4pneral run of balled and burlapped stock,

It is of interest to note that this treatment has been applied to 25
-varieties of hydrangeas with no damage and in most cases a noticeable accel-
oration of growth. Ninety-two varieties of azaleas have been treated and
only two of these have shown definite injury. This treatment has been
authorized, and shipments of fumigated plants are being made at the present


Oriental Fruit Moth

V.Work with the oriental fruit moth, taken up at the suggestion of J.
Cowl Damson, State entomologist of Missouri, in 1936, when a few small lots
9UPeach nursery stock in which hibernating larvae had been placed were fumi-
continued during the winter of 1936-37 with approximately 25,000
Uiberuating larvae of this insect. The larvae were in cocoons in corrugated
or had spun cocoors among twigs or in holes in small branches pre-
PAVOd for that purpose.

In carrying, out this project it was necessary to design a fumiga-
tion box that was tizht and that could be heated readily and brought up to a
fairly: constant temperature. Such a box was built of galvanized iron, in-
sulated and equipped with a fan for mixing the methyl bromide with the air and
an electric heater thermostatically controlled. The box was self-contained
ka that it was: only necessary to plug it in in a light circuit to make it
mady. for use.

In the experimental work the cocooned insects were placed in among
brush in the box in as nearly natural conditions as possible, and after fumi-
gation =wt of the insects "re placed at outside temperatures for a period
to-simlatbnatuxal conditions. Dosages of from 1 to 4 pounds were used, and
it irw fouad that 2-1/2 and 4 pounds of methyl bromide per 1, 000 Cbio feet.