Note: Descriptions are shown in the official language in which they were submitted.
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Tilis invention concerns the new use of known
compounds and formula~ions containing them.
Pests of the Order Acarina are a source of
concern in animal husbandry as troublesome pests of
many domestic animals. They transmit a variety of
infectious diseases by biting the animals, and can
cause loss of conditions, weight loss and decrease in milk yield~
a -Cyano-3-phenoxybenzyl-2,2-dimethyl-3-~2,2-
~ dibromovinyl)cyclopropane-l-carboxylate, and its
J 10 optical and geometric isomers, (hereinafter referred
I to as the compounds of formula (I))~ are known to have
insecticidal activity agains`t a variety of insects
including Musca domestica ~see for example British
Patent Specification No. 1,413,491 and 1,448,228).
1l /Br
~----CH.O~.CH -- ~ CH.CH=C
tI): ~ O ~ CN / \ Br
The structural formula (I) is intended to cover
all the geometric and optical isomers of the compound
including the (~-cis-isomer, the (+)-trans-isomer, the
~+)-trans-isomer, the (+)-cis-isomer and the (*)-cis-
trans-isomer ~the sterochemistry referring to that of
the cyclopropane ring). ~oreover the alcohol moiet~ of the ester
of fon~la ~I) may be selected from the ~ isomer, the ~+~-isomer and
the (+~-isomer. ~le preferred isomer is ~-)-a-cy~no-3-pheno~b~n~yl-~+)-
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cis-2,2-dimetllyl-3-(2,2-dibromovinyl)cyclopropane-1-
carboxylate, (Decamethrin).
It has now been found that the compounds of
- formula ~I) are very active against pests of the Order
~ Acarina, and that this activity is greater than that
Tj 5 which could have been foreseen from its known activity
-~ . against insects.
The compounds of formula (I) are highly
., effec~ive against strains of acarines which are sus-
ceptible to conventional organophosphorus acaricides
as well as to those strains which are resistant to
~ conventional organophosphorus acarlcides such as
~ Boophilus microplus and B. decoloratus (Koch). The
3 ~ompounds of formula (I) may therefore be used to
control acarine ectoparasites of animals, including
single host and multi-host ticks, particularly those
of the genera BooPhilus, Rhipicephalus, Amblyomma,
; Hyalomma, Ixodes, Haemaphysalis, Dermacentor, and
Anocentor, and mites of veterinary importance for
example, the sheep scab mite Psoroptes ovis, and
other ectoparasites of the sub-Orders Ixodoidea,
Trombidiformes and Sarcoptiformes. Such ectoparasites
infest stock and domestic animals and fowls, depending
upon the location of the host and the particular
ectoparasite. Common hosts are cattle, pigs, sheep,
goats, horses, camels, chickens, dogs and cats.
; The compounds of formula (I) may be used for
such purposes by application of the compounds themselvcs
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or in a diluted form in known fashion as a dip, spray,
foam, dust, aqueous suspension, paste, gel, shampoo,
,
grease~pressùre-pack, impregnated article or pour-on fo~llation. Dip
concentrates are not applied ~ se, but diluted with water and the
~- 5 animals immersed in a dipping bath containing the dipwash. Sprays may be applied by hand or by means of a
spray race or arch. The animal
may be saturated ~Jith the spray by means of high
volume~or superficially coated with the spray by ~ ~ licatl~n
means of light or ultra low volume application. Aqueous
~` - suspensions may be applied to the animal in the same
manner as sprays. Dusts ma~ be distributed over the
ahimals by means of a powder applicator or incorpGrated in
perforated bags attached to trees or rubbing bars.
Pastes, shampoos and greases may be applied manually
or distributed over the surface of an inert material
against which animals rub and transfer the material
to their skins. Pour-on formulations are dispensed
:
as a unit of liquid of small volume on to the backs of
animals such that all or most of the liquid is retained
on the animals~
The compounds of formula tI) may be formulated
either as formulations ready for use on the animals or
as formulations requiring further dilution prior to
appl~cation, but both types of formulations comprise a
compound of formula (I) in intimate admixture with one
or more carriers or diluents. The carriers may be
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liquid, solid or gaseous or comprise mixtures o~ such
substances, and the compound of formula (I) may be
present in a concentration of from 0.025 to 99~ w/v
depending upon whether the formulation requires further
dilution.
Dusts may be prepared by intimate admixture of
the chosen compound with a powdered solid inert carrier
for example suitable clays, kaolin, talc, mica, starch
and diatomaceous earths.
Sprays of a compound of formula (I) may comprise
a solution in an organic solvent (e.g. those listed
below) or an emulsion in wat~er (dip wash or spray wash)
prepared in the field from an emulsifiable concentrate
(otherwise known as a water miscible oil) which may
also be used for dipping purposes. The concentrate
preferably comprises a mixture of the active ingredient,
with or without an organic solvent and one or more
emulsifiers. Solvents may be present in wide limits but
preferably in an amount of from 20 to 60% w/v of the
composition and may be selected from kerosene, ketones,
alkanols, xylene, aromatic naphtha, and other solvents
known in the formulating art. The concentration of
emulsifiers may be varied within wide limits but
preferably in *he range of 5 to 25% w/v and are conveniently
non-ionic surface active agents including polyoxyalkylene
esters of al~yl phenols and polyoxyethylene derivatives
of hexitol anhydrides.
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Dip wahses may be prepared not only from
emulsifiable concentrates but also from wettable powders
comprising a compound of formula (I) in initmate
admixture with a dispersing agent and one or more surface
active agents.
Aqueous suspensions of a compound of formula (I)
may comprise a suspension in water together with
suspending, stabilizing or other agents. The suspensions
may be applied per se or in a diluted form in known fashion.
; 10 Greases ~or ointments) may be prepared from
vegetable oils, synthetic esters of fatty acids or wool
fat together with an inert base such as soft paraffin. A
- ~ compound of formula (I) is preferably distributed uniformly
through the mixture in solution or suspension. Greases may
lS also be made from emulsifiable concentrates by diluting
them with an ointment base.
Pastes and shampoos are also semi-solid preparations
in which a compound of formula (I) may be present as an
uniform dispersion in a suitable base such as soft or
liquid paraffin or made on a non-greasy basis with glycerin,
mucilage or a suitable soap. As greases, shampoos and
pastes are usually applied without further dilution they
should contain the appropriate percentage of the compound
of formula (I) required for treatment.
Aerosol sprays may be prepared as a simple solution
of the active ingredient in the aerosol propellant and
a co-solvent such as halogenated alkanes and the solvents
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; referred to above, respectively. Pour-on ormulations
; may be made as a solution or suspension of a compound
of formula ~I) in a liquid medium l~hich also contains
a viscous oil to minimise spreading of the formulation
' 5 on the surface of the animals.
`i . An avian or mammal host may also be protected against
j infestation of Acarine ectoparasites by means of
carrying a suitably-moulded, shaped plastic article
impregnated with a compound of formula (I). Such
articles include impregnated collars, tags, bands, sheets and
- strips suitably attached to appropriate parts of the body.
The concentration o the compound of formula (I)
to be applied to an animal will vary according to the
isomer chosen, the interval between treatments, the
nature of the formulation and the likely infestation,
but in general 0.001 to O.l~w/v of the compound should
be present in the applied formulation. The amount of
the compound deposited on an animal will vary according
to the method of application, size of the animal,
concentration of the compound in the applied formulation
and the nature of the formulation.
Dusts, greases, pastes and aerosol formulations
are usually applied in a random fashion as described above
and concentrations ofO.OOlto 1.0~ w/v of a compound of
formula (I~ in the applied formulation may be used.
It will be appreciated from the foregoing that
what ws wi]l claim may comprise any novel feature dsscribbd
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herein, principally and not exclusively, for example:-
(a) A method of controlling infestations by pests
of the Order Acarina of mammals and birds which
comprises application to the mammal or bird of a non-toxic
S infestat.ion prevention or minimisation effective amount
of a compound of formula (I) (as hereinbefore defined)
or of a formulation comprising said compound in intimate
admixture with a carrier or diluent therefor.
The following Examples illustrate the present
invention and the manner in which it may be carried out
but should not be construed as in any way constituting a
limitation thereof; In the Examples, compound Decamethrin
. refers to (-)-a-cyano-3-phenoxybenzyl-(l)-cis-2,2-
dimethyl-3-(2,2-dibromovinyl)cyclopropane-l-carboxylate.
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EXAMPLE 1
Engorged female ticks of the Biarra strain of
Boophilus micro~Ius are in~ersed, in groups of 20 ticks
per concentration, in a range of dilutions of a wash
comprising Decamethrin in an organic solvent and
emulsifiers emu~sified in water. The desired range of
concentrations for the test is obtained by further
dilution of this master wash.
The ticks are removed from the wash after 10
; minutes, dried, and stuck dorsal side do~ on double-sided
adhesive tape. They remain in this position for 14 days
when the numbers laying viable eggs are determined.
From this data a regression line is plotted (concentration
against ~ inhibition of egg production) and the IR90 and
IR99 values determined.
; IR90 a concentration at which 90~ inhibition
of egg production occurs.
. ~ .
.j IR99 = concentration at which 99~ inhibition
~.,
~ of egg production occurs.
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Decamethrin had an IR90(~) of 0.0019 and IR99(~)
of 0.0039.
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EXAMPLE 2
Wettable Powder Formulations
(a) ~ w/w(b) ~ w/w
Decamethrin 2.5 25.0
*Celite 209 68.5 51.0
Kaolin 25.0 20.0
*Perminal BX 1.0 1.0
: *Dispersol AC 3.~ ~.0
100.0 100.0
Celite 209 is an inert carrier.
Perminal BX and Dispersol AC are wetting
agents.
EXAMPLE 3
Miscible-oil Pormulations
-
(a) ~ w/w (b) ~ w/w
Decamethrin 2.5 19.0
Cyclohexanone - 15.0
~Esso 200 Solvent 85.0 53.5
Anionic/Non-ionic 12.5 12.5
Emulsifier 1OO 0 100 0
-
Esso 200 Solvcnt is a mobile oil which consists
of 95~ of aromatic hydrocarbons.
*trade marks
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EXAMPLE_4
Dusting Powder Formulations .
(a) % w/w (b) ~ w/w
Decamethrin 0.005 1.0
Talc 99.995 gg,o
~, 100. 000 .100. 0
.,' .
EXA~PLE 5
Aqueous SusPensions
(a) ~ w/w (b) ~ w/w
Decamethrin 5.0 20.0
: Aerosol OTB 0.2 0.2
. .
Keltrol 0.8 0.6
Water 74.0 64.2
Glycerol 20.0 15.0
., 100.0 100.0
. Aerosol OTB is a wetting agent
Keltrol is a thickening/suspending agent.
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EX~IPLB 6
Pressure~packed Aerosol Formulations ~ w/w
; ta) (b) ~c) (d)
Decamethrin 0.20 0.10 0.05 0.01
Methylene chloride 25.00 44.90 39.95
Iso-propyl alcohol 14.80 - - 19.99
Refined Petroleum Solvent - 55.00 20.00
50/50 trichlorofluoro methane/ 60.00
dichlorodifluoro methane
Butane/Propane mixture - - 40.00
Water - ~ ~ 40-00
Dimethyl ether - - - - 40.00
- 100.00 100.00 100.00 100.00
- The butane/propane mixture is chosen so as to
have a pressure of 40 pounds per square inch at 21C.
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~ EXAMPLE 7
,.
Larval ticks were tested for their susceptibility
to Decamethrin by the Shaw Immersion teclmique. The
immersion technique is described in the following references:-
Shaw R.D. ~]966): Culture of an Organophosphorus-
- resistant strain of B. microplus _~Can.~ and an Assessment
, of its resistance spectrum, Bull. Ent. Res., 56, 389-405.
Shaw R.D. Cook M., Carson R.E. (1968): Development
in the resistance status of the southern cattle-tick to
organophosphorus and carbamate insecticides, J. Econ. Ent.,
; 61, 1590-1594. The results are illustrated in Table 1.
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TABLE 1
Act_v~ ecamethrin a~ainst larval ticks
Species Strain _ LC50(%) LC99(%
B. microplus Yeerongpilly C~ 0.000027 0.00014
Biarra 0.000058 0.00025
.. Mackay 0.000063 0.00031
.l Mt. Alford 0.00012 0.00037
B. decoloratus Berlin 0.000061 0.00030
R. evertsi Three Breezes <o.0001
LC50(~) is the concentration of Decametnrin
required to kill 50~ of the larval ticks
LC99(%) is the concentration of Decamethrin
required to kill 99% of the larval ticks.
TABLE 2
A comparison of the activity of certain acaricide.s_a~ainst
larval and engorged female Biarra strain B. microPlus t _ks
Larvae Engorged female
LC50 LC99 IR90 IR99
Compound _ pPm .. .~E~ -
Pyre~rins 0.8 1.9 30008700
Allethrin 60.0 240.0 530010,000
Bioallethrin 12.0 72.0 41009800
Resmethrin 1.2 5.0 14002700
Bioresmethrin 1.4 5.6 47009500
Permethrin 0.7 2.1 6201400
Cypermethrin 4.2 11.0 _ _
Decamethrin 0.58 2.5 1939
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LC50 is the concentration required
to kill 50% of the ticks.
LC99 is the concentration required
to kill 99~ of the ticks.
IR90 is the concentration at which 90% inhibition
of egg-production occurs.
IR99 is the concentration at which 99% inhibition
of egg-production occurs.
EXAMPLE 8
Two groups of five sheep infested with HCH
resistant Psoroptes ovis were dipped once in a wash
containing 0.005% w/v of Decamethrin. This treatment
gave complete control against these pests throughout the
duration of the fourteen week trial.
.
EXAMPLE 9
Calves carrying infestations of the Biarra strain
of B. microplus were each hand-sprayed with eight litres of
decamethrin at concentrations of either 0.001% or 0.0025%
weight per volume using a motorised pump and lance t80-100
p.s.i.). The washes were prepared by appropriate dilution
- of a 20% weight per volume miscible-oil.
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Observations, recording the number of engorged
female ticks falling from the calves were made pre-
treatment and then a~ter treatment for the period of the
trial.
Samples of engorged female ticks were incubated
to monitor oviposition and larval hatch rate. Skin scrapes
were made at intervals after treatment to determine effec~.
', Larval tick infestations were continued for up to 14 days
after treatment to determine the residual period of
protection against reinfestation.
'; The results show that against a heavy infestation
: of ticks control was achieved at both 0.001~ and 0.0025
~ weight per volume of decamethrin.
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