# Patent

## Title
Use of an aromatase inhibitor in the treatment of decreased androgen to

## Abstract

This application is a 371 of PCT/JP97/04497, filed Dec. 8, 1997.

## Background
This invention relates to insecticidal and miticidal compositions which can be effectively applied in the agrohorticultural field. In more detail, it relates to insecticidal and miticidal compositions which contain two or more active ingredients and are especially effective against pests and mites which have acquired resistance to commercial insecticidal and miticidal agents.

4-Bromo-2-(4-chlorophenyl)-1-(ethoxymethyl) -5-(trifluoromethyl)pyrrole-3-carbonitrile (hereinafter referred to as chlorfenapyr), which is an active ingredient of the insecticidal and miticidal composition of the invention, is known to be effective against insects such as Hemiptera pests such as leafhoppers (Dolto cephalidae), Lepidoptera pests such as diamond back moth (Plutella xylostella), common cutworm (Spodoptera litura) and apple leafminer (Phyllonorycter ringoniella) and Thysanoptera pests such as Thrips palmi and yellow tea thrips (Spirtothrips dorsalis) and agrohorticultural pests such as mites such as two-spotted spider mite (Tetranychus urticae koch), Kanzawa spider mite (Tetranychus kanzawai kishida) and Aculops pelekassi [Japanese Laid-open (Kokai) Patent Publication No. 104042/89].

The second active ingredient of the insecticidal and miticidal composition of the invention includes one or more of the organophosphoric acid ester-type compounds which are known to be effective insecticidal and miticidal agents against agrohorticultural pests such as Hemiptera, Lepidoptera and Coleoptera insects and mites, and fungicidal agents against blast and soil born diseases of paddy rice.

Although insecticidal and miticidal agents have been developed in order to control various pests such as agrohorticultural pests or hygienic pests and in practice have been used as a single or a mixed agent, pests which have acquired resistance against various agents have been appearing as a result or the repeated use of these agents.

In particular, important economic pests in agrohorticulture such as spider mites (Tetranychidae), which have a propensity to easily develop resistance against pesticidal agents due to their ability to deposit large numbers of eggs and produce large numbers of generations which, themselves, require only a few days for development are of great concern. Resistance development in this pest family is also favored by a high mutation rate and frequent inbreeding, due to minimal migration. For these reasons, two-spotted spider mite (Tetranychus urticae koch), Kanzawa spider mite (Tetranychus kanzawai kishida), Aculops pelekassi, and the like have acquired resistance, to some degree, against almost all existing pesticidal agents. Therefore, in order to prevent and control the damage caused by spider mites, development of a new insecticidal and miticidal agent which shows a high effect against spider mites which have acquired resistance against the conventional miticidal agents is highly desirable.

However, to obtain an insecticidal and miticidal composition which shows no cross-resistance with existing insecticidal and miticidal agents, has no toxicity problems and has little negative impact on the environment, is extremely difficult. Therefore, a means to delay or prevent the development of resistant strains of pest species is always being sought. In order to apply an effective agent as long as possible, a rotational application of agents with different mechanisms of action is adopted for good pest management practice.

However, this approach does not necessarily give satisfactory pest control. Therefore, after a resistance problem has occurred, a countermeasure to resistance by combining insecticidal and miticidal agents has been studied. However, a high synergistic action has not always been found.

Therefore, it is an object of this invention to provide an insecticidal and miticidal composition which demonstrates a high controlling effect even against spider mites which have acquired resistance against chlorfenapyr.

In order to establish a countermeasure to a resistance problem in spider mites against chlorfenapyr before such a problem occurs, the synergistic action with the existing insecticidal, miticidal and fungicidal agents was studied using resistant species which have been artificially established in the laboratory by selecting spider mites which have been treated with chlorfenapyr. Thus, it has now been found that an insecticidal and miticidal composition which contains as active ingredient chlorfenapyr in combination with at least one of the designated organophosphoric acid ester-type compounds shows a joint action or synergistic effect which could not be foreseen from each individual ingredient alone.

The insecticidal and miticidal composition of the invention is particularly effective for the control of spider mites such as two-spotted spider mites (Tetranychus urticae koch). Tetranychus cinnabarinus (Boisduval), Kanzawa spider mite (Tetranychus kanzawai kishida), hawthorn spider mite (Tetranychus viennensis zacher), and the like.

Advantageously, the insecticidal and miticidal composition of the invention shows not only a synergistic miticidal effect against the above-mentioned spider mites, but also demonstrates simultaneous control of troublesome pests such as leafroller moths (Tortricidae), Carposinidae, leafminer moths (Lyonetiidae), plant bugs (Pentatomidae), aphids (Aphididae), leafhoppers (Deltociphalidae), Coccinea, thrips (Thripidae), diamond back moths (Plutella xylostella), Mamestra brassicae, leaf beetles (Chrysomelidae), whiteflies (Aleyrodidae) and the like on important agronomic crops such as fruit trees, for example citrus, apple and pear; tea plants; vegetables and the like.

Chlorfenapyr, which is an active ingredient of the insecticidal and miticidal composition of the invention, is a known compound described in Japanese Laid-open (Kokai) Patent Publication No. 104042/89 and its way of using as agrohorticultural insecticidal and miticidal agent is shown in the Publication. It can also be easily synthesized according to the method described in the Publication.

Organophosphoric acid ester-type compounds which are suitable for use as the second active ingredient in the composition of the invention are compounds represented by the general formulae (I) or (II), ##STR1##

wherein --S(CH.sub.2).sub.n S-- (n is 1 or 2) or single bond, alkylthio group, C.sub.1 -C.sub.4 alkylcarbonylamino group, C.sub.1 -C.sub.6 alkylamino group or phenyl group, and group, amino group, phenyl group, or heteroaryl group, which are unsubstituted or substituted by 1 to 4 same or different substituents selected from the substituent group A mentioned below, or the following formula (III) ##STR2##

(wherein R.sup.1, R.sup.2 and X mean the same as the above-mentioned).

Substituent group A: C.sub.1 -C.sub.8 alkyl group, C.sub.1 -C.sub.8 alkoxy group, C.sub.1 -C.sub.6 aliphatic acyl group, C.sub.1 -C.sub.6 alkoxycarbonyl group, C.sub.1 -C.sub.6 alkylthio group, C.sub.1 -C.sub.6 alkylamino group, di-C.sub.1 -C.sub.6 alkylamino group, C.sub.1 -C.sub.4 alkylsulfinyl group, C.sub.1 -C.sub.4 haloalkyl group, N--C.sub.1 -C.sub.4 alkylcarbamoyl group, N,N-di-C.sub.1 -C.sub.4 alkylcarbamoyl group, N--C.sub.1 -C.sub.4 alkyl-N-formylcarbamoyl group, heteroaryl group which may be substituted, phenyl group which may be substituted, halogen atom, nitro group, cyano group, hydroxy group and acetylamino group.

In the general formulae (I) and (III), the "C.sub.1 -C.sub.6 alkyl group" in the definition of R.sup.1 is a straight chain or branched chain alkyl group with 1 to 6 carbon atoms, such as, for example, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, i-pentyl, 2-methylbutyl, neopentyl, 1-ethyl-propyl, n-hexyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,3-dimethylbutyl and 2-ethylbutyl.

In the general formulae (I) and (III), "C.sub.1 -C.sub.8 alkoxy group" in the definition of R.sup.2 is a straight chain or branched chain alkoxy group with 1 to 8 carbon atoms, such as, for example, methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, n-pentoxy, i-pentoxy, 2-methylbutoxy, neopentoxy, n-hexyloxy, 4-methylpentoxy, 3-methylpentoxy, 2-methyl-pentoxy, 3,3-dimethylbutoxy, 2,2-dimethylbutoxy, 1,1-dimethylbutoxy, 1,2-dimethylbutoxy, 1,3-dimethylbutoxy, 2,3-dimethylbutoxy, n-hepty(oxy and n-octyloxy.

The "C.sub.1 -C.sub.8 alkylthio group" in the definition of R.sup.2 is a straight chain or branched chain alkylthio group with 1 to 8 carbon atoms, such as, for example, methylthio, ethylthio, n-propylthio, i-propylthio, n-butylthio, n-pentylthio, n-hexylthio, n-heptylthio and n-octylthio.

The "C.sub.1 -C.sub.4 alkylcarbonylamino group" in the definition of R.sup.2 is a carbonylamino group, to which a straight chain or branched chain alkyl group with 1 to 4 carbon atoms is bound, such as, for example, methylcarbonylamino, ethylcarbonylamino, n-propylcarbonylamino, i-propylcarbonylamino, n-butylcarbonylamino. s-butylcarbonylamino and t-butylcarbonylamino.

The "C.sub.1 -C.sub.6 alkylamino group" in the definition of R.sup.2 is an amino group, to which a straight chain or branched chain alkyl group with 1 to 6 carbon atoms is bound, such as, for example, methylamino, ethylamino, n-propylamino, i-propylamino, n-butylamino, i-butylamino, s-butylamino, t-butylamino, n-pentylamino and n-hexylamino.

In the general formulae (I) and (II), the "C.sub.1 -C.sub.8 alkyl group" in the definition of R.sup.3 and the substituent group A is a straight chain or branched chain alkyl group with 1 to 8 carbon atoms, such as, for example, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, i-pentyl, 2-methylbutyl, neopentyl, 1-ethylpropyl, n-hexyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,3-dimethylbutyl, 2-ethylbutyl, n-heptyl and n-octyl.

The "C.sub.2 -C.sub.6 alkenyl group" in the definition of R.sup.3 is a straight chain or branched chain alkenyl group with 2 to 6 carbon atoms, such as, for example, vinyl, 1-propenyl, 2-propenyl, 1-methyl-2-propenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 2-ethyl-2-propenyl, 1-butenyl, 2-butenyl, 1-methyl-2-butenyl, 2-methyl-2-butenyl, 3-methyl1-2-butenyl, 1-ethyl-2-butenyl, 3-butenyl, 1-methyl-3-butenyl, 2-methyl-3-butenyl, 1-ethyl-3-butenyl, 1-pentenyl, 2-pentenyl, 1-methyl-2-pentenyl, 2-methyl-2-pentenyl, 3-pentenyl, 1-methyl-3-pentenyl, 2-methyl-3-pentenyl, 4-pentenyl, 1-methyl-4-pentenyl, 2-methyl-4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl and 5-hexenyl.

The "heteroaryl group" in the definition of R.sup.3 and the substituent group A is a 5- to 8-membered heterocyclic group, which may be condensed and contains 1 to 5 same or different atoms selected from oxygen atom, sulfur atom and nitrogen atom, such as, for example, furanyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, thianyl, pyridyl, pyridazinyl, pyrazolyl, imidazolyl, triazinyl, thiadiazolyl, imidazothiazolyl, benzoisoxazolyl, chromenyl, quinolinyl, benzothianyl, quinixalinyl and benzotriazinyl.

The "C.sub.1 -C.sub.8 alkoxy group" in the definition of the substituent group A is a straight chain or branched chain alkoxy group with 1 to 8 carbon atoms, such as, for example, methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, n-pentoxy, i-pentoxy, 2-methylbutoxy, neopentoxy, n-hexyloxy, 4-methylpentoxy, 3-methylpentoxy, 2-methylpentoxy, 3,3-dimethylbutoxy, 2,2-dimethylbutoxy, 1,1-dimethyl-butoxy, 1,2-dimethylbutoxy, 1,3-dimethylbutoxy, 2,3-dimethylbutoxy, n-heptyloxy and n-octyloxy.

The "C.sub.1 -C.sub.6 aliphatic acyl group" in the definition of the substituent group A is a straight chain or branched chain aliphatic acyl group with total carbon atoms of 1 to 6, such as, for example, formyl, acetyl, propionyl, butyryl and valeryl.

The "C.sub.1 -C.sub.6 alkoxycarbonyl group" in the definition of the substituent group A is a carbonyl group, to which a straight chain or branched chain alkoxy group with 1 to 6 carbon atoms is bound, such as, for example, methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl, n-butoxycarbonyl, i-butoxycarbonyl, t-butoxycarbonyl, n-pentoxycarbonyl and n-hexyloxycarbonyl.

The "C.sub.1 -C.sub.6 alkylthio group" in the definition of the substituent group A is a straight chain or branched chain alkylthio group with 1 to 6 carbon atoms, such as, for example, methylthio, ethylthio, n-propylthio, i-propylthio, n-butylthio, i-butylthio, s-butylthio, t-butylthio, n-pentylthio and n-hexylthio.

The "C.sub.1 -C.sub.6 alkylamino group" in the definition of the substituent group A is an amino group, to which a straight chain or branched chain alkyl group with 1 to 6 carbon atoms is bound, such as, for example, methylamino, ethylamino, n-propylamino, i-propylamino, n-butylamino, i-butylamino, s-butylamino, t-butylamino, n-pentylamino and n-hexylamino.

The "Di-C.sub.1 -C.sub.6 alkylamino group" in the definition of the substituent group A is an amino group, to which two same or different straight chain or branched chain alkyl groups with 1 to 6 carbon atoms are bound, such as, for example, dimethylamino, diethylamino, methylethylamino, dipropylamino and dibutylamino.

The "C.sub.1 -C.sub.4 alkylsulfinyl group" in the definition of the substituent group A is a sulfinyl group, to which a straight chain or branched chain alkyl group with 1 to 4 carbon atoms is bound, such as, for example, methylsulfinyl, ethylsulfinyl, n-propylsulfinyl, i-propylsulfinyl, n-butylsulfinyl, i-butylsulfinyl, s-butylsulfinyl and t-butylsulfinyl.

The "C.sub.1 -C.sub.4 haloalkyl group" in the definition of the substituent group A is a straight chain or branched chain haloalkyl group with 1 to 4 carbon atoms, such as, for example, fluoromethyl, chloromethyl, bromomethyl, difluoromethyl, dichloromethyl, dibromomethyl, trifluoromethyl, trichloromethyl, 2-fluoroethyl, 2-chloroethyl, 2-bromoethyl, 2,2,2-trifluoroethyl, 3-fluoropropyl, 3-chloropropyl, 3-bromopropyl, 2,2,3,3,3-pentafluoropropyl, 2,2,2-trifluoro-1-methylethyl, 4-fluorobutyl, 4-chlorobutyl, 4-bromobutyl and 2,2,3,3,4,4,4-heptafluorobutyl.

The "N--C.sub.1 -C.sub.4 alkylcarbamoyl group" in the definition of the substituent group A is a carbamoyl group, to which a straight chain or branched chain alkyl group with 1 to 4 carbon atoms is bound, such as, for example, N-methylcarbamoyl, N-ethyl-carbamoyl, N-n-propylcarbamoyl, N-i-propylcarbamoyl, N-n-butylcarbamoyl, N-i-butylcarbamoyl, N-s-butylcarbamoyl and N-t-butylcarbamoyl.

The "N,N-di-C.sub.1 -C.sub.4 alkylcarbamoyl group" in the definition of the substituent group A is a carbamoyl group, to which two same or different straight chain or branched chain alkyl groups with 1 to 6 carbon atoms are bound, such as, for example, N,N-dimethylcarbamoyl, N,N-diethylcarbamoyl, N-ethyl-N-methylcarbamoyl, N-methyl-N-propylcarbamoyl and N-i-propyl-N-methylcarbamoyl.

The "N--C.sub.1 -C.sub.4 alkyl-N-formylcarbamoyl group" in the definition of the substituent group A is a formylcarbamoyl group, to which a straight chain or branched chain alkyl group with 1 to 4 carbon atoms is bound, such as, for example, N-formyl-N-methylcarbamoyl, N-ethyl-N-formylcarbamoyl, N-formyl-N-n-propylcarbamoyl, N-formyl-N-i-propylcarbamoyl. N-formyl-N-n-butylcarbamoyl, N-formyl-N-i-butylcarbamoyl, N-formyl-N-s-butylcarbamoyl and N-formyl-N-t-butylcarbamoyl.

The "halogen atom" in the definition of the substituent group A is, for example, fluorine atom, chlorine atom, bromine atom and iodine atom.

Among the generic names and chemical names exemplary of the organophosphoric acid esters represented by the general formulae (I) and (II) are those names shown below. These examples, however, are not intended to limit the scope of the invention.

Generic name: Chemical name O,O-Dimethyl-S[5-methoxy-1,3,4-thiadiazol-2(3H)nyl-(3)-methyl]dithiophosph ate O-Ethyl-O-2-isopropoxycarbonylphenylisopropylphosphoramidothioate O,O-Dimethyl-O-3,5,6-trichloro-2-pyridylphosphorothioate (RS)-(O-1-(4-chlorophenyl)-pyrazol-4-yl)-O-ethyl-S-propyl-phosphorothioate O,O-Diethyl-O-(3-oxo-2-phenyl-2H-pyridazin-6-yl)phosphorothioate 2-Diethylamino-6-methylpyrimidin-4-yl-dimethylphosphorothioate

The above-mentioned names of insecticidal and fungicidal agents are generic names described in "Agrochemicals Handbook 1992 Edition" published on Jul. 30, 1992 by Japan Plant Protection Association and "SHIBUYA INDEX-1996-(7th Edition)" published on Apr. 1, 1996 by ZENNOH.

In this invention, among the above-mentioned agents, especially O,O-dimethyl-O-p-cyanophenylthiophosphate (CYAP), ethylparanitrophenylthionobenzenephosphonate (EPN), O,O-disopropyl-S-benzylthiophosphate (IBP), O,O-dimethyl-O-(3-methyl-4-nitrophenyl)thiophosphate (MEP), O,O-dimethyl-O-[3-methyl-4-(methylthio)phenyl]-thiophosphate (MPP), ethyl dimethyldithiophosphorylphenylacetate (PAP), O,O,O',O'-tetraethyl-S,S'-methylenebisphosphorodithioate (Ethion), O,O-diethyl-O-3,5,6-trichloro-2-pyridylphosphorothioate (Chlorpyrifos), O,O-dimethyl-O-3,5.6-trichloro-2-pyridylphosphorothioate (Chlorpyrifosmethyl), O-ethyl-O-4-methylthiophenyl-S-propyl-phosphorodithioate (Sulprofos), (2-isopropyl-4-methylpyrimidyl-6)-diethylthiophosphate (Diazinon), O,O-diethyl-O-(3-oxo-2-phenyl-2H-pyridazin-6-yl)phosphorothioate (Pyridaphenthion), O-2,4-dichlorophenyl-O-ethyl-S-propylphosphorodithioate (Prothiophos), 3-diethoxyphosphorylthiomethyl-6-chlorobenzoxazolone (Phosalone) and dimethyidicarbethoxyethyidithiophosphate (Malathon) are preferable due to a high synergistic action with chlorfenapyr.

For the preparation of the insecticidal and miticidal composition of the invention, it is suitable to formulate as a wettable powder, aqueous concentrate, emulsion, liquid concentrate, sol (flowable agent), powder, aerosol, or the like, by conventional methods such as admixing chlorfenapyr and organophosphoric acid ester-type compound(s) with a suitable carrier and auxilliaries, such as emulsifiers, dispersants, stabilizers, suspending agents, penetrants, and the like.

The content of the total active ingredients of the composition of the invention, expressed as weight/weight %, is preferably in the range of about 1-90% for wettable powder, aqueous concentrate, emulsion, liquid concentrate and sol formulations. The preferable content of total active ingredients is about 0.5-10% for powder formulations and about 0.01-2% for aerosol formulations.

Carriers suitable for use in the insecticidal and miticidal compositions of the invention may be any solid or liquid carrier which is commonly used for an agrohorticultural composition. Various surfactants, stabilizers and other auxiliary ingredients may be used according to the necessity.

In commercially useful formulations, the composition of the invention may also be present in a mixture with other active agents, for example various insecticidal, miticidal, fungicidal and herbicidal agents, plant growth regulators, repellants, attractants, synergists and fertilizers and fragrances, in order to expand its applicability.

The ratio of chlorfenapyr to the organophosphoric acid ester-type compound(s) in the insecticidal and miticidal composition of the invention is about 1 weight part of chlorfenapyr to about 0.01-100 weight parts, preferably about 0.5-20 weight parts, of an organophosphoric acid ester-type compound(s).

Although the application amount may differ according to prevailing conditions such as the population density, the kinds and cultivation form of the target crop, the weather conditions, the manner of application, and the like, in general, the total amount of chlorfenapyr in combination with the organophosphoric acid ester-type compound(s) is about 0.1-1,000 g, preferably about 20-500 g, per 10 ares. In actual practice, the composition of the invention when in the form of a wettable powder, aqueous concentrate, emulsion, liquid concentrate, sol, or the like may be diluted with water and applied to the crop at an application rate of about 100-700 liters per 10 ares. When the inventive composition is formulated as a powder or aerosol, the crop may be treated with the undiluted formulation.

The insecticidal and miticidal composition of the invention is further illustrated in the examples set forth hereinbelow. These examples are not intended to limit the scope of the invention. The parts all mean weight parts. FORMULATION EXAMPLE 1 EMULSION Clorfenapyr                   5 parts CYAP                         40 parts Xylene                       25 parts Dimethyl formamide           20 parts Sorpol 3005X                 10 parts (Polyoxyethylene type surfactant manufactured by Toho Chemical Industry Ltd. commercial name)

An emulsion is obtained by mixing homogeneously and dissolving the above-mentioned ingredients. FORMULATION EXAMPLE 2 WETTABLE POWDER Chlorfenapyr                    5 parts PAP                            50 parts Carplex #80                    15 parts (White carbon manufactured by Shionogi & Co. Ltd., commercial name) Zeeklite SP                    22 parts (Mixture of kaolinite and cericite manufactured by Zeeklite Ind., commercial name) Calcium ligninsulfonate         8 parts

A wettable powder is obtained by homogeneously mixing the above-mentioned ingredients by jet air mill. FORMULATION EXAMPLE 3 SOL (FLOWABLE AGENT) Chlorfenapyr                       5 parts Chlorpyrifosmethyl                 25 parts Ethylene glycol                    8 parts Sorpol AC3020                      5 parts (Toho Chemical Ind. Co., Ltd., commercial name) Xanthan gum                       0.1 parts Water                            56.9 parts

Chlorfenapyr, chlorpyrifosmethyl and a previously prepared mixture of ethylene glycol, Sorpol AC3020 and xanthan gum are well mixed in water and dispersed. This slurry is then wet pulverized by Dynomill (Shinmaru Enterprises) to obtain a sol (flowable agent). FORMULATION EXAMPLE 4 POWDER Chlorfenapyr                 0.5 parts MEP                          3.5 parts White carbon                   5 parts Clay                          91 parts (Nippon Talc Co. Ltd., commercial name)

The above-mentioned ingredients are homogeneously mixed and pulverized to obtain a powder.

Each of the above-prepared formulations is suitable to be used as an agrochemical.

In this experiment, the miticidal effect against female imagines (adults) of Kanzawa spider mite (Tetranychus kanzawai kishida) which are resistant to chlorfenapyr is evaluated.

Round leaf disks (2 cm diameter) are cut out of a first leaf of kidney bean by a leaf punch and 4 sheets of the disks are placed on wet sanitary cotton in a plastic cup (8 cm diameter). On each leaf disk, 4 female imagines of Kanzawa spider mite (Tetranychus kanzawai kishida) which had acquired a strong resistance to chlorfenapyr are inoculated.

After the inoculation, chlorfenapyr and an organophosphoric acid ester-type compound(s) are dispersed in water containing 200 ppm of an extender (Sorpol 3005X manufactured by Toho Chemical Industry Ltd.) and diluted such that a predetermined concentration of active ingredient is obtained. Each plastic cup is sprayed with 3.5 ml of a test solution with a rotary spray tower (Mizuho Scientific Co., Ltd.) and stored in a constant temperature chamber held at 25.+-.1.degree. C. (32 individuals are tested per concentration, 4-5 concentrations are evaluated per formulation and 2 performances are repeated). Two days after treatment, the number of living and dead female imagines of Kanzawa spider mite (Tetranychus kanzawai kishida) which had acquired a strong resistance to chlorfenapyr is counted and the mortality (%) is calculated according to the formula shown hereinbelow. ##EQU1##

Using these data, the LC.sub.50 values are obtained by conventional probit analysis techniques. A co-toxicity coefficient is calculated by applying Sun and Johnson's formula (J. Econ. Ent., Vol 53, p. 887, 1960) which is generally used to determine the degree of synergistic activity.

The LC.sub.50 value of each individual effective ingredient which constitutes the insecticidal and miticidal composition of the invention is shown in Table I. The LC.sub.50 values and the co-toxicity coefficients of the composition of the invention are shown in Table II.

Co-toxicity coefficient=T.sup.c ##EQU2##

For T.sup.c values greater than 100, the greater value indicates a stronger synergistic action. For a T.sup.c value equal to 100, an additive action is indicated. For T.sup.c values less than 100, the lesser value indicates a greater antagonistic action. A more detailed description of the calculation or the co-toxicity coefficient using the above-referenced Sun and Johnson formula follows.

The LC.sub.50 values of Test Compound A alone and Test Compound B alone and the LC.sub.50 value of the (A+B) mixture M are determined.

Actual toxicity index of mixture M=M.sup.ti

Each LC.sub.50 value of effective ingredient A and effective ingredient B and the LC.sub.50 value of the mixture of A+B are used to determine the actual toxicity index as shown in the equation below. ##EQU3##

Theoretical toxicity index of mixture M=Th.M.sup.ti in M

Toxicity index of B=B.sup.ti ##EQU4##

Toxicity index of A=A.sup.ti Evaluation Of The Effect Of Test Compounds Against Female Imago Of Kanzawa Spider Mite Which Have Acquired Resistance Against Chlorfenapyr TEST COMPOUND             LC.sub.50 (ppm) Chlorfenapyr                    1500 CYAP                            3200 EPN                             3100 IBP                             1300 MEP                             3200 MPP                             1100 PAP                             2000 Ethion                          3100 Chlorpyrifos                    3200 Chlorpyrifosmethyl                790 Sulprofos                        320 Diazinon                        3200 Pyridaphenthion                 1900 Prothiophos                      260 Phosalone                        350 Malathon                        3400

The tested mite was a female imago of the chlorfenapyr-resistant strain of Kanzawa spider mite which was obtained by a long artificial selection procedure against chlorfenapyr in a laboratory on a colony of Kanzawa spider mite which had been collected in the field. As the LC.sub.50 value for chlorfenapyr against a susceptible strain of spider mite is about 5 ppm, this strain has developed about a 300-fold resistance to chlorfonapyr.

As this Kanzawa spider mite was from a colony which had acquired resistance to organophosphoric acid esters already at the time of collection in the field, all the tested organophosphoric acid esters showed only low miticidal effects. Evaluation Of The Effect Of Test Mixtures Against Female Imago Of Kanzawa Spider Mite Which Have Acquired Resistance Against Chlorfenapyr RATIO (Chlorfenapyr:other LC.sub.50 TEST MIXTURE                    ingredient)     (ppm)  T.sup.C Chlorfenapyr + CYAP                1:8           310    920 Chlorfenapyr + EPN                 1:9           300    930 Chlorfenapyr + IBP                 1:12          460    290 Chlorfenapyr + MEP                 1:11          130   2300 Chlorfenapyr + MPP                 1:10          290    390 Chlorfenapyr + PAP                 1:10          180   1100 Chlorfenapyr + Ethion              1:10          120   2400 Chlorfenapyr + Chlorpyrifos        1:8           220   1300 Chlorfenapyr + Chlorpyrifosmethyl       1:5           97     880 Chlorfenapyr + Sulprofos           3:20          170    210 Chlorfenapyr + Diazinon            5:34          430    650 Chlorfenapyr + Pyridaphenthion       1:10          340    550 Chlorfenapyr + Prothiophos         1:9           100    280 Chlorfenapyr + Phosalone           1:7           180    220 Chlorfenapyr + Malathon            1:10          370    820

As can be seen from the data on Table II, the co-toxicity coefficient of the test mixtures is a value greater than 100, which is indicative of strong synergistic action between chlorphenapyr and the organophosphoric acid ester-type compound(s). Though the detailed mechanism of the synergistic action of the composition of the invention is not clear, it is estimated that the metabolic system (group of enzymes), with which the spider mites, which has developed resistance to chlorfenapyr, detoxifies and decomposes the compound, be inhibited by an organophosphoric acid ester-type compound(s) to demonstrate such an action. Therefore, a second ingredient of the insecticidal and miticidal composition is thought not to be limited to the organophosphoric acid ester-type compounds tested in the above-mentioned examples and the organophosphoric acid ester-type compounds specifically named above.

## Claims

1. An insecticidal or miticidal composition which contains as active ingredients synergistic amounts of chlorfenapyr and one or more compounds of formula I ##STR3## wherein -C.sub.4 alkylcarbonylamino, C.sub.1 -C.sub.6 alkylamino or phenyl, and ##STR4## wherein R.sup.1, R.sup.2, and X are as defined above.

2. The composition of claim 1 wherein chlorfenapyr is present in a ratio of about 1 weight part to about 0.01-100 total weight parts of the compound of formula I.

3. The composition of claim 1 wherein the compound of formula I is O,O,O',O'-tetraethyl-S,S'-methylenebisphosphorodithioate.

4. The composition of claim 3 wherein chlorfenapyr is present in a ratio of about 1 weight part to about 0.01-100 total weight parts of O,O,O',O'-tetraethyl-S,S'-methylenebisphosphorodithioate.

5. The composition of claim 4 wherein chlorfenapyr is present in a ratio of about 1 weight part of chlorfenapyr to about 0.5-20 weight parts of O,O,O',O'-tetraethyl-S,S'-methylenebisphosphorodithioate.

6. A process for the preparation of a composition of claim 1 which comprises admixing the active ingredients with an agrohorticulturally acceptable solid or liquid carrier.

7. The process of claim 6 wherein the active ingredients comprise chlorphenapyr and O,O,O',O'-tetraethyl-S,S'-methylenebisphosphorodithioate.

8. The process of claim 7 wherein chlorfenapyr is present in a ratio of about 1 weight part of chlorfenapyr to about 0.5-20 weight parts of O,O,O',O'-tetraethyl-S,S'-methylenebisphosphorodithioate.

9. A method of controlling insecticidal or miticidal pests which have acquired resistance to chlorphenapyr at a locus which comprises applying to the locus an effective amount of an insecticidal and miticidal composition comprising as active ingredients synergistic amounts of chlorphenapyr and one or more compounds of formula I ##STR5## wherein -C.sub.4 alkylcarbonylamino, C.sub.1 -C.sub.6 alkylamino or phenyl, and ##STR6## wherein R.sup.1, R.sup.2, and X are as defined above.

10. The method of claim 9 wherein chlorfenapyr is present in a ratio of about 1 weight part to about 0.01-100 total weight parts of the compound of formula I.

11. The composition of claim 9 wherein the compound of formula I is O,O,O',O'-tetraethyl-S,S'-methylenebisphosphorodithioate.

12. The composition of claim 11 wherein chlorfenapyr is present in a ratio of about 1 weight part to about 0.01-100 total weight parts of O,O,O',O'-tetraethyl-S,S'-methylenebisphosphorodithioate.

13. The composition of claim 12 wherein chlorfenapyr is present in a ratio of about 1 weight part of chlorfenapyr to about 0.5-20 weight parts of O,O,O',O'-tetraethyl-S,S'-methylenebisphosphorodithioate.