Note: Descriptions are shown in the official language in which they were submitted.
CA 02270680 1999-OS-04
Pesticidal Method and Composition
The present invention relates to a new pesticidal method for the control of
weevils, e.g. Otiorynchr~s ,sulcatus and to a new composition.
It is presently known that weevils, such as Otiorynchu.s .sulcalus (also known
as
S Black Vine Weevil) are destructive pests in agriculture and horticulture.
The insects may
inhabit potted plants which are available at commercial horticultural markets.
A problem
to overcome in the control of these insects in horticultural markets is
actually detecting
the presence of the larvae of the insects. Although detection of adults may be
readily
done by observing feeding damage on the leaves, damage by larvae is
particularly
insidious and difficult to detect because the larvae damage the plants by
destroying the
roots. Thus by the time damage is detected the plant may not have a reasonable
chance to
recover after treatment.
An object of the invention is the control of weevils, such as Otiorynchus
.sr~lcatus
and others mentioned hereinafter.
Another object of the invention is the prevention of damage by weevils, such
as
Otiorynchus sulcatus, to plants, e.g. ornamental plants.
Another object of the invention is to provide a new composition for the
control of
weevils such as Oliorynchus sulcatus and others mentioned hereinafter.
These objects are met in whole or in part by the instant invention.
The present invention provides a method of protecting a plant, eg an
ornamental
plant, a soft fruit plant (e.g. strawberry or raspberry) or pine, from weevils
which method
comprises applying to a growing medium in which the plant is growing or is to
be grown
an insecticidally effective amount of a 1-arylpyrazole of formula (I):
R2 R~
R4 /N.N (1)
R» / - X
Ris
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wherein:
R, is CN or methyl or a halogen atom;
RZ is S(O)~R3or 4,5-dicyanoimidazol-2-yl or haloalkyl;
R, is alkyl or haloalkyl;
R4 is selected from the group consisting of hydrogen, halogen, -NRSR~, -
C(O)OR,, -S(O)mR,, alkyl, haloalkyl, -ORR,
-N=C(R9)(R,~) and -C(O)alkyl;
RS and R~ are independently selected from a hydrogen atom, alkyl, haloalkyl, -
C(O)alkyl, -C(O)OR,, -S(O),.CF3; or RS and R~ form together a divalent
alkylene radical
which may be interrupted by one or more heteroatoms, preferably selected from
oxygen,
nitrogen and sulfur;
R, is selected from alkyl and haloalkyl;
Rg is selected from alkyl, haloalkyl and hydrogen;
R9 is selected from hydrogen and alkyl;
Rlo is selected from phenyl and heteroaryl each of which is unsubstituted or
substituted by one or more hydroxy, halogen, -O-alkyl, -S-alkyl, cyano, or
alkyl or
combinations thereof;
X is selected from nitrogen and -C-R,z;
RI, and R,Z are independently selected from halogen, hydrogen, CN and NO2;
R,3 i selected from halogen, haloalkyl, haloalkoxy,
-S(O)qCF3 and -SFS;
m, n, q, r are independently selected from 0, 1, and 2;
provided that when R, is methyl, R3 is haloalkyl, R4 is NHZ, R,1 is Cl, R,3 is
CF3,
and X is N and provided that when RZ is 4, 5-dicyanoimidazol-2-yl, R4 is Cl,
Rl, is Cl,
R,3 is CF3, and X is =C-Cl.
The alkyl and alkoxy groups and moieties thereof of the formula (I) are
preferably
lower alkyl and alkoxy groups, that is, groups having one to six carbon atoms.
The
haloalkyl and haloalkoxy groups likewise preferably have one to four carbon
atoms.
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The haloalkyl and haloalkoxy groups can bear one or more halogen atoms;
preferred
groups of this type include -CFj and -OCF,. It shall be understood that the
ring formed
by the divalent alkylene radical represented by RS and R~ and including the
nitrogen
atom to which RS and R~ are attached is generally a 5, 6, or 7-membered ring.
When
R", is heteroaryl, it is preferably pyridyl, most preferably 2-pyridyl. It
will be
understood that the 1-arylpyrazoles of formula (I) include enantiomers and/or
diastereomers thereof and mixtures thereof.
A preferred group of 1-arylpyrazoles for use in the present invention are
those of
formula (I) with one or more of the following features wherein:
R, is CN;
R4 is -NRSR6;
RS and R~ are independently selected from the hydrogen atom, alkyl, haloalkyl,
C(O)alkyl, C(O)OR.,;
X is C-R,z; or
R,3 is selected from a halogen atom, haloalkyl, haloalkoxy, and -SFS.
Another preferred group of 1-arylpyrazoles of formula (I) for use in the
present
invention is that wherein:
R, is CN;
R3 is a haloalkyl radical;
R4 is NHz;
X is C-Rlz;
Rl, and R,z represent, independently of one another, a halogen atom; and
R13 is a haloalkyl radical.
A most preferred compound is S-amino-1-(2,6-dichloro 4-trifluoromethyl phenyl)
4-trifluoromethylsulfinyl-3-cyanopyrazole, hereafter designated as compound
(A).
Compounds of formula (I) may be prepared according to known processes,
for example as described in International Patent Publications WO 87/3781,
93/6089, and
94/21606 as well as in European Patent Applications 295117, 403300, 385809 or
679650,
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German Patent Publication 1951 1269 and United States Patents 5232940 and
5236938 or
other process according to the knowledge of a man skilled in the art of
chemical
synthesis, which is deemed to include Chemical Abstracts and the literature
referred to
therein. Compositions comprising the compounds of formula (I) may also be
prepared
according to the teaching of the same prior art or similar publications.
The weevils may be of the Otiorynchus or Hylobius family, e.g. Otiorynchus
sulcatus, Otiorynchus ovatus (European strawberry) weevil, Otiorynchus
singularis which
attack soft fruit plants (e.g. strawberry and raspberry) and Hylobius abietis
(pine weevil).
By the term "growing medium" is meant a substance in which, for example, the
plant or the seed from which it grows may germinate and develop or into which
it may be
translated. Generally growing medium comprises compost, peat or potting soil.
To
facilitate even distribution of the 1-arylpyrazole in the growing medium, it
may be
applied to one or more components e.g. sand, perlite or water-retaining
granules of the
growing medium before that component is incorporated into the growing medium.
The
1 S content of 1-arylpyrazole in the treated component may be adjusted to
provide the desired
final concentration after mixing all the components of the growing medium.
Such treated
components also constitute a feature of the invention.
'Phe 1-arylpyrazole may be used in conjunction with other active ingredients,
for
example a plant feed or plant growth regulator. Compositions comprising a
plant feed or
plant growth regulator, a 1-arylpyrazole of general formula (I) and,
optionally, a carrier
and/or a surface active agent also constitute a feature of the invention.
The invention provides a growing medium for a plant which comprises an amount
of a 1-arylpyrazole of formula (I) effective to protect the plant or the seed
from which it
grows from weevil attack.
A growing medium in which the 1-arylpyrazole is substantially evenly or
uniformly
distributed throughout the medium is preferred. Preferably the I-arylpyrazole
is present
on granules which granules are substantially evenly or uniformly distributed
throughout
the growing medium. The invention also provides a growing medium comprising 1-
arylpyrazole as described herein which medium is packaged , for example in
plastics
bags, as seed compost, potting compost or general purpose compost. The compost
may
CA 02270680 1999-OS-04
be, for example soil-based or peat-based. Tlre plastics bags may simply
contain the
compost, quantities of which can be used as required or they may be in the
form of 'grow
bags' in which plants may be grown.
Generally the amount of the 1-arylpyrazole is from 0.01 g/m' to 20 g/m3, e.g.
0.01
S g/m' to 10 g/m', of 1-ary(pyrazole per volume of growing medium, preferably
from 0.2
g/m3 to S g/m', more preferably from 0.25 to 1 g/m'.
The method of the invention is preferably applied to plants grown in
containers,
for example pots, nets or other flexible material which contains the growing
medium.
The application of the 1-arylpyrazole is generally effected by a suitable
means
known to those skilled in the art. It is generally preferred to apply the 1-
arylpyrazole as a
particulate solid composition or a liquid composition to the growing medium.
It is more
preferable to apply the 1-arylpyrazole as a particulate solid composition in
order to
minimize the effective amount and more evenly distribute the active ingredient
in the
growing medium.
1S The 1-arylpyrazole is preferably incorporated in the growing medium as
granules.
The granules generally comprise from 0.02% to 2% by weight of 1-arylpyrazoie,
preferably O.OS to 0.5%, most preferably about 0.1% of arylpyrazole. The 1-
arylpyrazole
is preferably used in the form of granules~containing 0.1% by weight of 1-
arylpyrazole,
using from O.S to 2.Skg, preferably from 1 to 2kg, most preferably lkg of
granules per
cubic metre of growing medium. The invention accordingly provides a growing
medium
which comprises granules which granules generally comprise from 0.02% to 2% by
weight of 1-arylpyrazole. The granules are generally substantially evenly
distributed
throughout the growing medium.
The particle size of the granules is generally 100-1000~cm, preferably 200-
900~cm.
2S The bulk density is generally 30-60 lb/ft3 (480-960kg/m'), preferably 40-SO
lb/ft3
(640-800kg/m3), most preferably 42-4Slb/ft3 (670-720kg/m3). The granules may
be, for
example, the commercial product Chipco Choice 0.1 G formulated with a bulk
density 42-
4SIb/ft3 (670-720 kg/m3). A preferred particle size range is from 150 to
1000~cm,
preferably with)9S% of the granules from 3SS to 8S6~m more preferably with 6S%
>SOO~m.
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<~
The granules may contain a marker, for example a colouring agent, to
facilitate
monitoring of their distribution in the growing medium during mixing.
The I-arylpyrazole may also be incorporated into the growing medium by, for
example, spraying an aqueous dispersion of the 1-arylpyrazole onto the growing
medium
during its manufacture or processing.
In general the method of the instant invention is used preventatively: that
is, the
application of the 1-arylpyrazole is used to prevent or reduce attack by
weevils such as
Otivrynchu.s sulcatzrs on a plant. However, the invention may also be used
curatively in
that a planting medium infested with weevils such as Otiorynchus sulcatus or
others
mentioned above may be treated to kill a substantial majority of the insects
after the plant
has been affected. Generally in a curative treatment, it is preferred to apply
the 1-
arylpyrazole as a liquid composition to penetrate the planting medium quickly.
When a liquid composition is used the concentration of 1-arylpyrazole is
generally
from 0.2 grams per 100 litres to S grams per 100 litres of liquid composition,
for example
0.5 to 2 grams per 100 litres, for example about 1 gram per 100 litres.
The method of the invention may be used to provide long-term protection for
plants,
ornamental plants, from weevils such as Oliorynchus sulcatus. Generally, the
method of
the invention provides protection of from 0.1 years to -5 years, preferably
from 0.3 years
to 3 years, most preferably from 0.5 years to 2 years.
The following Examples illustrate the invention:
Example 1:
In a twenty-replicate test, Compound A was incorporated in compost by mixing a
2% w/w granule with the compost (Klasmann Substrat 2 (Peat based) ) using a
small
mechanical mixer. Plants of Thuya plicata Atrovirens were potted in the
compost and
allowed to grow for two months and then about 15 eggs of Otiorynchus sulcatus
were
added to the soil and covered with a small layer of compost. As a comparison,
some
compost was untreated and other compost was treated with the standard
chlorpyrifos in
the form of the commercial product suSCon Green~. After 27 days the soil was
re-
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infested with 15 more eggs. The plant pots were enclosed such that the plants
were
exposed to light and the adult beetles which emerged could not escape.
Of the twenty replicates of each test, five were assessed after 6 months and
fifteen
were assessed after 18 months for numbers of larvae and adults. After 6 months
the
following results were observed:
Compound Dose g/m3 Total # Number per % Control
larvae pot
Untreated 0 31 3.1 0
A 2.5 0 0 100
10A . S 0 0 100
A 7.5 0 0 100
A 15 0 0 100
Chlorpyrifos75 4 0.8 87
The following results were obtained after 18 months:
Compound Dose Total % Total Number
g/m3 Dead Survival # per pot Control
Plants of Plantslarvae
Untreated 0 7 72 51 3.1 0
A 2.5 0 100 0 0 100
A 5 0 100 0 0 100
A 7.5 0 100 0 0 100
A 15 0 100 0 0 100
Chlorpyrifos75 0 100 47 3.1 0
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Example 2
In 20-replicate tests, Fuchsia triphylla hybrid cv. Koralle was infested with
15
eggs per pot of vine weevil. Compound A in the form of an 80% water
dispersible
S granule (Regent 800 WG) was suspended in water and added to each pot at the
indicated
rate per surface area of the pot at various dilutions. After 6 months, the
trials were
assessed. Compound A protected the plants substantially better than the
commercial
standard fonofos in a curative treatment.
Drench Treatments
rt. ose m ota no. umber
No. mg rri litreof larvaeper Control
2 pot
1 Untreated Control 44 2.2
2 REGENT 800WG 1.25 5 25 1.25 43%
3 REGENT 800WG 1.25 10 30 1.5 32%
4 RESENT 800WG 1.25 20 12 0.6 73%
REGENT 800WG 2.5 5 10 0.5 77%
6 REGENT 800WG 2.5 10 18 0.9 59%
7 REGENT 800WG 2.5 20 10 0.5 77%
8 REGENT 800WG 'S 5 8 0.4 82%
9 REGENT 800WG 5 10 11 0.55 75%
REGENT 800WG 5 20 15 0.75 66%
11 REGENT 800WG 10 10 5 0.25 89%
12 Cudgel ml 2.5 10 32 1.6 27%
(fonofos)
IO
