CA1084837A

CA1084837A - Insecticidal and ovicidal compositions and method for using same

Info

Publication number: CA1084837A
Application number: CA287,639A
Authority: CA
Inventors: Edwin L. Sukman
Original assignee: M&T Chemicals Inc
Current assignee: M&T Chemicals Inc
Priority date: 1976-10-04
Filing date: 1977-09-27
Publication date: 1980-09-02
Also published as: IT1090775B; CH627620A5; AU507044B2; IL52889A0; JPS6210202B2; JPS5344631A; FR2366301B1; FR2366301A1; GB1561198A; ES462836A1; DE2743848A1; NL7710537A; AU2932477A; ZA775930B

Abstract

INSECTICIDAL AND OVICIDAL COMPOSITIONS AND METHOD FOR USING SAME

Abstract of the Disclosure - Insects and acarids are effectively controlled by applying to these organisms, their eggs or their habitat certain tertiary bis(halophenyl)-phosphines, phosphine oxides and phosphine sulfides. These compounds kill the adult, nymph and egg stages. At lower dose levels the compounds are effective chemosterilants for eggs of insects.

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Description

iL~84837 This invention relates to the control of insects.
This invention further relates to compositions for controlling insects ~nd aoarids that can be applied directly to these organisms, their eggs or to substrates, particularly plants, that are infested with these organisms.
Numerous phospho~us compounds have been disclosed as being effective control agents for insects and acarids. For example, United States Patent 2,754,242 teaches using alkyl bis (halophenyl) phosphinates to kill two-spotted spider mites.
Many of these ~ompounds are not practical for commercial use, since they must be present at relatively high concentration levels (500 parts per million or more) to be effective. The in-use cost of these prior art materials may therefore be so high as to exclude them for large-scale applications.
It has now been found that certain tertiary bis-(halophenyl)phosphines, phosphine oxides and phosphine sulfides are remarkable effective insecticides and acaricides that can be employed at lower concentration levels than heretofore possible using many structurally related prior art materials, including those disclosed in the aforementioned United States Patent 2,754,242.

~' Su~mary of the Invention This invention provides a method for killing B insects and sterilizing eggs of insects and acar~d~ by applylng to said insects, said eggs or to substrates susceptible to infestation with said insects or aoaride an insecticidally and ovicidally effective amount of a phosphorus compound exhibiting the formula:

Z =P-R P-R -(~)or (~!

! wherein R is selected from the group consisting of alkyl Il radicals containing ~etween 1 and 12 carbon atoms, alkenyl ~j and alkynyl radicals containing between 2 and 12 carbon atoms, ¦: cycloalkyl, aryl, alkaryl, aralkyl and haloalkyl radicals, ! x represents a halogen atom selected from the group consisting of fluorlne, chlorine, bromine and iodine atoms and Z represents ~j oxygen or sulfur. .

¦~ ~etailed Description of the Invention j The present insecticides and ovicides are tertiary bis(p-halophenyl)phosphines, phosphine oxides and phosphine ;I sulfides. When R of the preceding formulae represents an I alkyl radical, it may contain one or more halogen atoms as ~08~837 substituents. These compounds effectlvely control insects at considerably lower concentrations that can be achieved uslng structurally related compounds, such as the aforementioned j bisthalophenyl)phosphinates that are disclosed in the chemical ~ and patent literature. The comparative efficacy of the present compounds and the criticality of the substituents on both the phenyl radicals and the phosphorus atom are demonstrated in the accompanying examples. In addition to killing the nymph and adult stages of insects, the present compounds also inhibit o l! development o the eggs of both insects and acarids. At lower j, concentrations the present compounds function as chemosterilants.
!I While many known insecticides and ovicides are ii effective when sprayed onto infested plant leaves, the present il compounds are unique in that they can also be applied to the ~I soil surrounding the roots of the plant and are transported by the plant to the leaves, where insects and eggs are killed.
Many of the present tertiary bis(halophenyl)phosphines j are disclosed in the chernical literature. The phosphines are !I conveniently prepared by reacting the appropr-iate halophenyl ~1~ magnesium halide arid dichloroorganophosphine. The dichloro-organophosphines are either available from commercial suppliers l~ or can be synthesized using known preparative methods, for !, example those disclosed in "Organophosphorus Compounds" by ! G. M. Kosolapoff, published by John Wiley and Sons, Inc.

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The resultant bis(halophenyl)organophosphlne is readlly converted to the corresponding phosphine oxide or phosphine sulfide by reacting the phosph~ne with hydrogen peroxide or elemental sulfur, respectively.
Alternatively, the phosphine oxides can be prepared directly from a halophenylmagnesium halide by reacting it "` ,. O
with the appropriate organophosphonic dichloride, RPC12 The following examples provide specific methods for preparing and using representative compounds encompassed by the accompanying claims. All parts and percentages are by weight.
Example 1 - Bis(p-chlorophenyl)methylphosphine Oxide To 900 cc. of a sol~tion containing 1.143 moles of p-chlorophenylmagnesium bromide dissolved in tetrahydrofuran was added 73 g. (0.55 mole) of methylphosphonic dichloride O
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(CH3PC12) dissolved in 400 cc. of tetrahydrofuran. The addition required two hours, during which time the reaction mixture was stirred and the temperature maintained at between 30 and 40C.
Following completion of the addition the re~ction mixture was , heated to the boi~ing point for one hour, cooled and then 20 j extracted using 2 liters of chloroform. The chloroform layer was then dried using anhydrous magnesium sulfate and the solvent;
removed under reduced pressure. The solid residue was re-crystallized once from benzene to yield 90 g. of a white sol1d that el'ed between 167 and 169C. Analy~1~ of the _4_ I
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~084837 recrystallized product revealed a phosphorus content of 10.9 I and a chlorine content of 22.3%. The calculated phosphorus ¦ and chlorine content of bis(p-chlorophenyl)methylphosphine ~l~ oxide ls 10.9 and 24.9%, respectively. The structure of the compound was confirmed by nuclear magnetic resonance.
Example 2 - Bis(p-chlorophenyl)chloromethylphosphine Oxide To a solution containing 69 g. (0.39 mole) of chloromethylphosphonic dichloride and 400 cc. tetrahydrofuran ~ was added 285 cc. of a tetrahydrofuran solution containing 10 ~l 0.789 mole of p-chlorophenylmagnesium bromide. The addition was dropwise and required two hours, during which time the temperature of the reaction mixture was maintained at 30C.
Following completion of the addition the mixture was stirred for two hours while the temperature was maintained at 60C.
15 ~ After the mixture had cooled to ambient temperature 400 cc.
of water were gradually added, followed by 1200 cc. of methylene chloride. The organic layer was then separated, dried using anhydrous magnesium sulfate and the methylene chloride removed under reduced pressure. The residue was passed through a column of neutral alumina using ethyl acetate I .
as the eluent. The white solid obtained following removal of the eluent and one recrystallization of the residue from benzene weighed 90 g., melted between 114 and 117C. and exhibited the following analysis. chlorine - 32.8%;

phosphorus - 9.89%. The calculated values for bis(p-chloro-phenyl)chloromethylphosphine oxide are 33.3 and 9.70%, respectively. The nuclear magnetic resonance spectrum was consistent with the desired structure.

iOB4837 Example 3 - Bis(p-chlorophenyl)methylphosphlne To 12.6 g. of magnesium turnings was gradually added a solution containing 96 g. (0.50 mole) of p-chlorobromo-benzene and 180 cc. tetrahydrofuran. The reaction mixture was stirred and maintained under a nitrogen atomosphere during the addition, following which the contents of the vessel were heated to reflux temperature for two hours. When the reaction mixture had cooled, a solution of methyldichlorophosphine I (29.3 g., 0.25 mole) in 25 cc. tetrahydrofuran was gradually added. Following completion of this addition the reaction mixture was heated to reflux temperature for two hours. When the mixture had cooled it was slowly poured into 500 cc. of cold water and then acidified to a pH of 5 using aqueous hydro-1 chloric acid. The resultant aqueous solution was extracted 1 using chloroform. The organic layer was then dried over j anhydrous magnesium sulfate and the chloroform removed under il reduced pressure. The residue remaining following removal Or the chloroform weighed 64 g. and was distilled, the fraction Ij boiling at between 155 and 160 under a pressure of 0.5 mm. Hg 1~ being collected. This distillate converted to a white solid upor. cooling. The solid mâteriai weighed ~4 g. anà exhiDited ' the followlng analysls:
~¦ Found Calculated Phosphorus 10.9% 11.5%
Chlorine 25.9% 26.4%

~xample 4 - Bis(p-chlorophenyl)propylphosphine Sulflde Bis(p-chlorophenyl)propylphosphine was prepared by reacting 0.2 mole of propyldichlorophosphine with 0.4 mole of p-chlorophenylmagnesium bromide. The product was isolated by chloroform extraction and distillation as previously described. The portion boiling between 160 and 165~C. under a pressure of 2 mm. Hg was collected. The analysis corresponded to bis(p-chlorophenyl)propylphosphine.
¦ An 18 g. (0.061 mole) portion of the phosphine was ji combined with 150 cc. benzene, followed by 2.1 g. (0.065 mole) of sulfur. The resultant mixture was stirred for one hour and the solvent removed under reduced pressure. Following one recrystallization from diethyl ether the solld product ~ weighed 16 g. and melted between 102 and 107C. This product 1, was found to contain 9.21% phosphorus, 22.2% chlorine and 8.33~ sulfur. The calculated values ~or bis(p-chlGrophenyl) propylphosphine sulfide are 9.42, 21.6 and 9.73%, respectively.
~j When employed to control insects and acarids the Il present phosphines, phosphine oxides and phosphine sulfides ~ can be applied directly onto the insects, eggs~ infested plants ¦! cr to plants and other substrates -~hich are susceptible to ~, infestation by insects and acarids. The long term residual actl-vity and low phytotoxicity that characterize the present toxicant I makes it possibIe to apply these compounds to plants several days ¦ and in some inStanceS weeks, prior to the time when the plant wlll be expo ed to 1nsects or acar:lds.

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~84837 The present compounds are conventlonally applled to plants as a liquid spray, solid dust or a wettable powder.
Compositions suitable for spraying are usually -~
prepared by diluting liquid concentrates or wettable powders containing between 10 and 90% of the active toxican~. To avoid the expense of transporting formulations containing large amounts of inert diluents, the final dilution is usually performed at the location where the composition will be applied.
The concentration of toxicant in a spray for large scale ~ applications is between 10 and 1000 parts per million (ppm), preferably between 100 and 500 parts per million.
Solid dust compositions, which are generally applied over a relatively small area, contain between 1 and 50% by , weight of active toxicant, preferably between 1 and 10%.
1I The concentration of toxicant required in a given formulation will be dependent upon a number of parameters .!1 i including the method of application, i.e. whether at ground level or from aircraft, the activity of the particular toxicant ~,l against a given insect or acarid and weather conditions in the 2Q l! are~ being treated~
In the preparation of dust compositions or wettable powders, the present toxicants can be blended with many commonly employed finely divlded solids, such as fuller's earth, ¦
I attapulgite, bentonite, pyrophyllite, vermiculite, diatomaceous earth, talc, chalk, gypsum, wood flour, and the like. The finely divided carrier is ground or mixed with the lf)~4B~ ' toxicant or wetted with a dispersion of the toxicant in a volatile liquid. Depending upon the proportions of ingredients, these compositions can be employed as concentrates and sub-sequently diluted witn additional solid carriers to obtain the desired amount of active toxicant. Also, such concentrate dust compositions can be incorporated in intimate admixture ¦ with surface active dispersing agents such as ionic or nonionic emulsifying or dispersing agents to form spray concentrates.
I Such concentrates are readily dispersible in liquid carriers 1 to form spray compositions or liquid formulations containing ¦ the toxicants in any desired amount. The choice of surface active agent and amount e.~ployed are determined by the ability of the agent to facilitate the dispersing of the concentrate Il in the liquid carrier to produce the desired liquid compos~tion. ¦
ii Suitable liquid carriers include water, methanol, ethanol, ¦l isopropanol, methyl ethyl ketone, acetone, methylene chloride, ¦, chlorobenzene, toluene, xylene, and petroleum distillates.
Among the preferred petroleum distillates are those boiling I almost entirely under 205C. at atmospheric pressure and having I a ~lash point above about 30C.
Alternatively, the toxicant may be compounded with . .
a suitable water-immiscible organic liquid and a surface active dispersing agent to produce emulsifiable concentrates which may be further diluted with water and oil to form spray mixtures in the form of oil-ln-water emulsions. In such compositions, the carrier comprises an aqueous emulslon, i.e. .r I .
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- . ~ ' a mixture of water-lmmisclble solvent, emulsifying agent and water. Preferred dispersing agents which may be employed in these compositions are oil soluble and include the condensation j products of alkylene oxides with phenols and organic or , inorganic acids, polyoxyethylene derivatives of sorbitan esters, alkylarylsulfonates, complex ether alcohols, mahogany soaps and the like. Suitable organic liquids to be employed in the j' compositions include petroleum distillates, hexanol, liquid halohydrocarbons and synthetic organic oils. The surface active dispersing agents are usually employed in the liquid dispersions and aqueous emulsions in the amount of from about l to about 20 percent by weight of the combined weight of the dispersing agent and the active toxicant.
The following examples demonstrate the efficacy of the present compounds as insecticides and ovicides. Formulations were prepared by dissolving the compound to be tested in a mixture of acetone and a liquid alkyl-aryl polyether alcohol type surfactant (Triton~ X-155) and diluting the resultant composition to the desired concentration using a water-acetone mixture

2~ su^h that the linal formulation contained lO~ acetone and lO
parts per million (ppm) of the surfactant.

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; , , 1084~37 Example 5 The activity of a given compound as a contact acaricide against the two-spotted spider mite (Tetranychus urticae) was determined by transferring adult and nymph mites to the leaves of Sieva lima bean plants. Twenty four hours following the transfer the leaves were either sprayed with or dipped into the aforementioned formulation containing 200 ppm of the compound to be tested. If the compound was to be evaluated as a systemic acaricide and ovicide 21 cc. of a formulation containing 520 ppm of the active compound was poured into the soil surrounding the infested plant.
Nine to twelve days following application of the formulation the leaves of all plants were examined using a microscope to determine the number of dead mites and eggs.
The following compounds were found to be effective contact type acaricides at a concentration of 200 ppm, in that they killed at least 70% of the adult mites, nymphs and/or ' eggs.

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bis(p-chlorophenyl)ethylphosphlne oxide bis(p-chlorophenyl)ethylphosphlne bis(p-chlorophenyl)methylphosphine oxde bis(p-chlorophenyl)chloromethylphosphine oxide bis(p-chlorophenyl)propylphosphine oxide:
bis(p-chlorophenyl)methylphosphine sulfide bis(p-chlorophenyl.)methylphosphine bis(p-chlorophenYl)n-propylphosphine . bis(p-chlorophenyl)isopropylphosphine oxide bis(p-chlorop~enYl)t-butylphosphine oxide bis(p-bromophenyl)methylphosphine oxide bis(p-fluorophenyl)methylphosphine oxide The following compounds, which are structurally related to the present acaricides, were ineffective in I controlling spider mites or their eggs (l~ss than 30% of mites or eggs killed) at a concentration of 200 ppm.
!i diphenylmethylphosphine oxide diphenylchloromethylphosphine oxide bis(p-chlorophenyl)trichloromethylphosphine oxide bis(m-chlorophenyl)methylphosphine oxide tris(p-chlorophenyl)phosphine oxide bis(p-chloro-m-nitrophenyl)methylphosphine oxide bis(p-tolyl)methylphosphine oxide bis(m,p-dichlorophenyl)methylphosphine oxide bis(p-chlorophenyl)hydroxymethylphosphine oxide bis(p-chloro-o-methylphenyl)methylphosphine oxide Two of the most effect~ve acaricides, bis(p-chloro- !
phenyl)methylphosphinè oxide (A) and bis(p-chlorophenyl) chloromethylphosphine oxide (B) were evaluated further to : ascertain the lowest concentration at which these compounds are effective. The data from this test are summarized in the !
: following table, together with the results obtained using I` .
,j N'(4-chloro-o-tolyl)N,N-dimethylformamidine (Galecron~), a .
~I commercially accepted miticide and ovicide. All plants were ; rated twelve days after being sprayed with the test formulation.

, COMPOUND CONCENTRATION % CONTROL OFNO. OF
(PPM)ADULT MITES DEAD EGGS

Galecron~ (control) 400 65 135 ll 100 0 A formulation containing 100 ppm of bis(p-chloro-phenyl)chlorom~thylphosphine oxide was poured onto the soil surrounding the roots of a Sieva lima bean plant which was infested with spider mites and eggs. Six days later 97% of the adult mites and 90% of the eggs were dead on one leaf.
Examination of a second leaf revealed that 100% of the eggs had been killed.
Example 6 This example demonstrates the efficacy of bis(p-chlorophenyl)methylphosphine oxide as an insecticide and ovicide for the Mexican bean beetle.
Newly hatched Mexican bean beetles were confined ' in a cage for two days together with a number of untreated bean plants. On the thlrd day the beetles were classified `
according to sex. Seven emale and five male beetles were confined in a cage together with six bean plants which had been previously treated with an aqueous dispersion of the il ~ test compound. The dispersion was prepared by dissolving the requlr-d amount of com~ound ln a small amount of aoetone ~ -13-I!
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~013~37 together with 1000 parts per million (ppm) of a nonionlc sur~actant, an alkyl aryl polyether alcohol available as ~riton~ X-155 from the Rohm and Haas Company. The amount of acetone employed was calculated such that the final dispersion obtained following addition of the required amount of water contained 100 ppm of the surfactant. The resultant dispersion I containing a specified concentration of the test compound was ,i sprayed onto the leaves of the bean plants ~ust prior to 1~ introduction of the beetles. Two days following this introductior ~ a mortality count was taken. On the following day any egg clusters present were collected and six untreated plants were placed in the cage togethe~ with the beetles. The egg clusters, together with the area of the leaf on which they resided, were ~ removed and placed in a petri dish which remained for five days 1i in an incubator maintained at a temperature of 78C. and a ;~ relative humidity of 90%. Egg clusters were also collected on i the next two days from both the treated and untreated plants.
I Following removal from the incubator the egg clusters were placed ~1 ln transparent containers together with untreated bean plant ,¦ leaves. The percentage of eggs from each cluster which produced I! larvae W5 q observed and recorded. Any larvae which emerged ¦I were transferred to untreated bean plants for observation.
¦ The compounds tested were bis(p-chlorophenyl)methyl-I phosphine oxide (A) and bis(p-chlorophenyl)chloromethylphosphlne 11 oxide (B). While neither compound killed adult Mexican bean beetles, both compounds are effective ovicides, as demonstrated ;, by the data ln the accompanying table. Only a small fractlon of the eggs matured into larvae. The number of egg clusters deposlted was significantly reduced relative to beetles whlch fed on only untreated leaves. The two compounds tested exercise control by significantly reducing the second generation population.

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Ii ~ ~ ~ ~ ~% Eg~ Viability ~1 c~
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ol~ ¢ . ~ ~UntreatedTreated ~ o ~ ~ o ~ ~ Leaves Leaves ~ A 260 12 6 (untreated) 0,0,0,0,10,10 ~, 6 (treated) 0,0,0,0,0,0 A 130 12 9 (untreated) 0,0,0,0,0,0,0,

3 (treated) 0,100 0,0,0 B 260 10 4 (untreated) 0,0,0,0 7 (treated) 0,0,0,0,0,75,50 B 130 12 3 (untreated3 0,0,50 5 (treated) 0,100,100,25,0 j Control - 13 12 100 - Values given for each cluster evaluated.
Example 7 Four pair of adult Mexican bean beetles were allowed to feed on untreated bean plants for several days and then transferred to a cage containing bean plants which had pre~iously , been sprayed to run-off with an aqueous dispersion contalning 25 i 260 ppm of either bis(p-chlorophenyl)isopropylphosphlne oxide j or bis(p-chlorophenyl)t-butylphosphine oxide. All of I the beetles were dead after feeding on the treated foliage.
11 ' !

~1 1 108~837 A control group of the same size which was feeding on untreated plants exhibited no adverse effects.
¦ The dispersion employed to spray the bean plantB
was prepared :~ described ln the preceding Example 6.

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Claims

WHAT IS CLAIMED IS:

1. A method for killing insects and sterilizing the eggs of insects by applying to said insects, said eggs or to substrates susceptible to infestation with said insects an insecticidally and ovicidally effective amount of a phosphorus compound exhibiting the formula:

or wherein R is selected from the group consisting of alkyl and haloalkyl radicals containing between 1 and 12 carbon atoms, alkenyl and alkynyl radicals containing between 2 and 12 carbon atoms, cycloalkyl, aryl, alkaryl and aralkyl radicals, X represents a halogen atom selected from the group consisting of fluorine, chlorine, bromine and iodine and Z represents oxygen or sulfur.

2. The method of Claim 1 wherein the phosphorus compound is present in combination with a liquid or solid diluent at a concentration of between 1 and about 500 parts per million.

3. The method of Claim 1 wherein X is chlorine.

4. The method of Claim 1 wherein R represents an alkyl radical containing between 1 and 12 carbon atoms.

5. The method of Claim 1 wherein R is a methyl, chloromethyl, ethyl, isopropyl or t-butyl radical.

6. The method of Claim 1 wherein the substrate is a plant.

7. The method of Claim 6 wherein the phosphorus compound is applied to the leaves of said plant.

8. The method of Claim 6 wherein the phosphorus compound is applied to the soil adjacent to the roots of said plant.