Vinyl Dimethyl Phosphate Research Articles

Aerobic dichlorvos degradation by Pseudomonas stutzeri smk: complete pathway and implications for toxicity in Mus musculus

Excess use of pesticides in agricultural field not only compromised soil fertility but also posed serious threat to water bodies and life in the surrounding environment. The leftover pesticide residue needs to be remediated effectively. Compared to physical, chemical and enzymatic remediation options the microbial remediation is more practical and sustainable. The Pseudomonas stutzeri smk strain was found to use dichlorvos as the solitary carbon source. Minimal medium supplemented with dichlorvos was used to test ability of bacterium to degrade pesticide aerobically. The metabolites produced by the bacterium were studied with UV-Vis spectrophotometry, HPLC, FTIR and GC-MS techniques. The toxicity studies of neat dichlorvos and P. stutzeri smk degraded metabolites were studied by subcutaneous injection in Mus musculus. The P. stutzeri smk strain was found to degrade as high as 80% of dichlorvos on 7th day of incubation, at 30 °C temperature and at pH 7. In five steps complete aerobic degradation of 2,2dicholorvinyl dimethyl phosphate (dichlorvos) resulted in production of free methyl and phosphate. The degradation intermediates produced are 2-Chlorovinyl dimethyl phosphate, vinyl dimethyl phosphate, dimethyl phosphate, methylphosphate and finally free phosphate. The histopathological analysis of liver, spleen and thymus of M. musculus were performed to study toxicity of dichlorvos and degraded metabolites. P. stutzeri smk could result highest aerobic degradation of dichlorvos to produce free methyl and phosphate. Degradation metabolites could reverse largely toxic effects of dichlorvos when studied in M. musculus.

Residues of Stirofos (Rabon®) in Eggs of Laying Hens Treated for Northern Fowl Mite Control by Dipping ,

Laying hens were treated with a wettable powder formulation of stirofos [Rabon®, 2-chloro-l-(2,4,5-trichlorophenyl) vinyl dimethylphosphate] by dipping in a .5 or 1.0% actual ingredient (AI) water suspension of a 50% wettable powder (WP) stirofos formulation. Stirofos residues were detected in eggs within 1 day after treatment and reached maximum levels 3 days after dipping (.021 and .035 ppm in the low- and high-dose birds, respectively). After that time, levels of residues in eggs declined rapidly and no sample contained detectable quantities (<.004 ppm) of stirofos after 21 days. Dipping may be a practical control method for the northern fowl mite on chickens, because stirofos dips effectively control this mite on laying hens for at least 6 weeks and because resulting residues in eggs are well below established tolerances.

Sustained-release Rabon bolus for face fly control in cattle feces.

A sustained-release bolus containing 60% technical Rabon® [2-chlorol-(2,4,5-trichlorophenyl) vinyl dimethyl phosphate] was developed and shown capable of treating cattle feces for 184 days. Mature, fistulated Hereford heifers received either 1, 2, 4, or 6 Rabon® boluses, and feces was collected from each animal on days 8 and 15 posttreatment for bioassay in a Latin-square design (4 by 4) against Musca autumnalis De Geer. Near complete control was achieved with the four- and six-bolus treatments by demonstrated mortalities of 96 and 99%, respectively. Complete control was not achieved due to passage of several boluses from the reticulum to the rumen. This resulted in reduced erosion rates, lower Rabon® release, and thus lower larval mortality.

Crystal and molecular structure of organophosphorus insecticides. 9. Stirofos

The crystal and molecular structure of stirofos (2-chloro-1-(2,4,5-trichlorophenyl)vinyl dimethyl phosphate), (H/sub 3/CO)/sub 2/PO/sub 2/C/sub 8/H/sub 3/Cl/sub 4/, has been determined by three-dimensional x-ray analysis. The compound crystallizes in the triclinic space group P1: a = 14.023 (4), b = 15,088 (5), c = 6.930 (2) A, ..cap alpha.. = 93.94 (2), ..beta.. = 90.29 (4), and ..gamma.. = 98.97 (4)/sup 0/. The structure was solved via direct methods and refined to a final residual of R = 0.123. The two molecules per asymmetric unit assume nearly identical configurations with the orientation of the phosphate group relative to the planar organic moiety differing markedly from previous studies of organophosphorus insecticides. The average angle between the P=O bond and the normal to the plane of the ring system was 85.8/sup 0/ compared to 23.7/sup 0/ for ronnel, 38.4/sup 0/ for coroxon, 23.9/sup 0/ for azinphos-methyl, and 23.5/sup 0/ for amidithion. In addition, the partial charge on phosphorus (via a CNDO II molecular orbital calculation) differed considerably from previous studies, i.e., stirofos, +1.385 e; amidithion, +1.063 e; and azinphos-methyl, +1.041 e.

Use of some mono- and ditetrazolium salts as spectrophotometric reagents for determination of ?Gardona?

The optimum conditions for the reaction between “Gardona” [2-chloro-1-(2,4,5-trichlorophenyl) vinyl dimethyl phosphate] and some mono- and ditetrazolium salts for analytical purposes have been determined. The analytical procedure has been applied to determining the amount of this insecticide in polluted river water and in fruit (apples).

Effect of Insecticides on Growth and Zearalenone (F-2) Production by the Fungus, Fusarium graminearum1

When added to liquid media, malathion, MGK®264(N-octyl bicycloheptene dicarboximide), and naled, at concentrations of 100μl/l (insecticide:media), completely inhibited the production of zearalenone (F-2) by Fusarium graminearum . F-2 production was completely inhibited in cultures treated with 30 and 10μl/l naled and was reduced by 53% in cultures treated with one μl/l naled. All insecticides except methoxychlor inhibited growth and/or F-2 production by at least 38% at concentrations of 10 and/or 30μl/l. In cultures treated with insecticides at levels of 30–100 μl/l and in those treated with diazinon, naled, dichlorvos, ethion, and pyrethrins at concentrations of 1–10 μl/l, the reduced level of F-2 production was a consequence of reduced mycelial growth. At lower concentrations of one and/or 10 μl/l, azinphosmethyl, malathion, allethrin, Rabon® (2-chloro-1-2,4,5-trichlorophenyl) vinyl dimethyl phosphate), piperonyl butoxide, MGK®264, and mevinphos reduced F-2 production without reducing mycelial growth. Naled was fungicidal at concentrations of 100 μl/l and fungistatic at levels of 1, 10, or 30 μl/l.

Metabolism of the insecticide SD 8280, 2‐chloro‐1‐(2,4‐dichlorophenyl)vinyl dimethyl phosphate, following its application to rice

AbstractThe metabolism of the insecticide SD 8280 [2‐chloro‐1‐(2,4‐dichlorophenyl)vinyl dimethyl phosphate] in rice plants has been examined. When rice seedlings were treated with [14C]‐SD 8280 the major metabolite was 1‐(2,4‐dichlorophenyl)ethanol which was present mainly conjugated with plant carbohydrates. This compound was also the major metabolite present in grain and straw from rice treated with [14C]‐SD 8280 and grown to maturity under paddy conditions both in the glasshouse and in an outdoor enclosure. Other metabolites detected in the mature plants included 2‐chloro‐1‐(2,4‐dichlorophenyl)vinyl methyl hydrogen phosphate and 2,4‐dichloro‐benzoic acid, both of which occurred in free and conjugated forms. Paddy water was sampled at intervals after the application of [14C]‐SD 8280 and the total residue in the water fell from initial levels of 0.28–1.1 μg/ml (expressed as SD 8280 equivalent) immediately after treatment to &lt;0.01 μg/ml after 2–3 weeks. The total residues in the soil from these experiments were low and did not exceed 0.20 mg/kg (SD 8280 equivalents) through the 0–15 cm profile.

Degradation of the insecticide SD 8280, 2‐chloro‐1‐(2, 4‐dichlorophenyl)vinyl dimethyl phosphate, in soils

AbstractThe degradation of the insecticide SD 8280 [2‐chloro‐1‐(2,4‐dichlorophenyl)vinyl dimethyl phosphate] in soil has been examined under laboratory conditions using two soils from rice‐growing areas in Japan and one UK soil. In all soils SD 8280 underwent degradation to 1‐(2,4‐dichlorophenyl)ethanol, 2,4‐dichlorobenzoic acid, 2‐chloro‐1‐(2,4‐dichlorophenyl)vinyl methyl hydrogen phosphate and 2′,4′‐dichloro‐acetophenone. These degradation products were present in the soils as free (extractable) compounds and as bound forms and soil binding occurred most extensively with 2,4‐dichlorobenzoic acid. Polar products were also formed and these appeared to be in part the result of complexing of degradation products with the soil organic matter. The effect on the degradation of the insecticide of varying the moisture content of one soil was also examined. In soil incubated at 11, 17, 30 and 62% moisture the recovery of SD 8280 after 60 days was 71.0, 12.3, 9.0 and 11.3%, respectively. Although the rate of degradation varied, the same degradation products were detected in all samples.

The use of chlordimeform against northern fowl mites on caged laying hens

Trials were conducted to evaluate the efficiency of chlordimeform ( N ′-(4-chloro- o -tolyl)-( N , N -dimethylformamidine)) in controlling northern fowl mites on commercial caged laying hens. Chlordimeform (0.03% active ingredient (A.I.)) applied as a high pressure spray was as effective ( P < 0.05) as stirofos (2-chloro-1-(2,4,5-tri-chlorophenyl) vinyl dimethyl phosphate) (0.5% A.I.) for 63 days post-treatment. Twenty-one days after treatment, chlordimeform (0.06% A.I.) was shown to be more effective ( P < 0.05) than stirofos when applied as a low pressure spray. Des essais ont été conduits pour évaluer l'efficacité du chlordimeform ( N ′-(4-cloro- o -tolyl)- N , N ′-dimethylformamidine) pour le contrôle d'acerien Ornithonyssus sylviarum (Canestrini & Fanzago) des poulets de pontes commercials en cage. Chlordimeform (0.03% active ingredient (A.I.)) appliqué avec un vaporisateur à haut pression était aussi efficace que ( P < 0.05) stirofos (2-chloro-1-(2,4,5-tri-chlorophenyl) vinyl dimethyl phosphate) (0.5% A.I.) pour 63 jours après traitement. Vingt et un jours après traitement, chlordimeform (0.06% A.I.) s'est montré plus efficace ( P < 0.05) que stirofos appliqué avec un vaporisateur à bas pression.

Control of the Fall Cankerworm12

For 2 consecutive years, foliar sprays of acephate, Bacillus thuringiensis . Berliner, Sevimol®, Gardona® (2-chloro-1-[2,4,5-trichlorophenyl] vinyl dimethyl phosphate), and malathion have resulted in excellent control when applied onto larvae of Alsophila pometaria (Harris) feeding on American linden trees.

A Gardona-Vapona Mixture for Control of Stored-product Insects in Railway Boxcars1

Adult confused flour beetles, Tribolium confusum Jacquelin duVal, adult granary weevils, Sitophilus granarius (L.), adult lesser grain borers, Rhyzopertha dominica (F.), and Trogoderma inclusum LeConte larvae were exposed in railway boxcars to 3 dosages of a Gardona®: Vapona®, (2-chloro-1-[2,4,5-trichlorophenyl] vinyl dimethyl phosphate): (2,2-dichlorovinyl dimethyl phosphate) formulation. Following application, some of the Vapona concentrations were monitored. With few exceptions a 3.78 liter/boxcar application rate provided 80–100% mortality of the test insects. However, all dosages above 0.95 liter/boxcar resulted in a Vapona air concentration above the 1 mg/liter allowed for human exposure.

Synergist Ratios, Epn Detoxication, Lipid, and Drug-Induced Changes in Carbaryl Toxicity in Megachile pacifica1

Megachile pacifica (Panzer) generally became more susceptible to carbaryl as adults aged. LD50 values for carbaryl toxicity were 240, 166.5, 109.2, and 51.3 μg/g for the 1, 2, 3, and 4-day-old adult male bees. For the female bees, these values were 245.5, 550.5, 289.4, and 262.4 μ/g. Lipid content and in vitro EPN detoxication decreased in both sexes as the bees aged. Synergist ratios were measured. They are the ratio of the LD50 of carbaryl alone to the LD50 of carbaryl applied after the synergist piperonyl butoxide. These ratios, which did not correlate with either decreasing LD50 values or decreasing EPN detoxication in the males, were 12, 21, 42, and 53 for the 1, 2, 3, and 4-day-old bees. female bees the synergist ratios corresponded more closely. They were 23, 49, 11, and 15 as the females aged from 1 to 4 days. The bees were very susceptible to the organo-phosphates monocrotophos, dicrotophos, or Gardona® [2-chloro-1-(2,4,5-trichloro-phenyl) vinyl dimethyl phosphate], (LD50 < 2 μg/g), but they were quite tolerant the carbamate Landrin® (3,4,5-trimethylphenyl methylcarbamate; 2,3,5-trimethylphenyl methylcarbamate). The use of enzyme-inducing drugs to protect bees from carbaryl poisoning was studied. Among the 3 drugs used, only chlorcyclizine increased the LD50 value (to ca. 2-fold) in the 4-day-old male. Aminopyrine increased the male's susceptibility carbaryl while phenobarbital had no effect at all. None of the drugs significantly changed the female's susceptibility to carbaryl except aminopyrine which lowered LD50 from 262.4 to 75.3 μg/g. Studies with in vitro EPN detoxication indicated that all 3 drugs caused increases in microsomal enzyme activity up to 4 or 5-fold and decreases in lipid content of ca. 20–30%.

Effects of ULV Organophosphates on Horn Flies and Face Flies of Cattle, and on the Bovine Coprocoenosis 1

A study in east-central South Dakota during the summers of 1971 and 1972 evaluated insecticidal control of horn and face flies ( Haematobia irritans (L.) and Musca autumnalis De Geer, respectively) on cattle, as well as potential side effects to the insects of the bovine coprocoenosis. Three organophosphate compounds were aerially applied in ULV formulations: Ravap®, a 1:4 mixture of dichlorvos and Rabon® [2-chloro-1- (2,4,5-trichlorophenyl) vinyl dimethyl phosphate)], Rabon, and malathion. All 3 insecticides reduced the number of adult flies of both species for at least 1 day but for less than 1 wk. No residual control was noted. No significant effects to the dung biota could be attributed to Ravap or malathion. Rabon significantly (P=0.01) diminished only numbers of Platystethus americanus Erichson, Falagria dissecta (Erichson), Aphodius fimetarius (L.), and Cercyon pygmaeus Illiger, and, to a lesser degree (P=0.05), a miscellaneous group of unidentified dipterous larvae and larval hydrophilids. Most of the dung fauna, however, were unaffected by the insecticides.

Insecticide Susceptibility and Response to Selected Pollens of Larval Alfalfa Leafcutting Bees, Megachile pacifica (Panzer) (Hymenoptera: Megachilidae) 1

A method for rearing larvae from field-collected eggs of Megachile pacifica (Panzer) was used to measure insecticide toxicities, synergist ratios, and larval growth on 4 pollen species. Carbaryl, propoxur, Landrin® (3,4,5-trimethylphenyl methylcarbamate and 2,3,5-trimethylphenyl carbamate) and methomyl had LC50 values ranging from 42–121 ppm. Gardona® [2-chloro-1-(2,4,5-trichlorophenyl) vinyl dimethyl phosphate] and monocrotophos were more toxic with LC50 values of about 1.7 and 2.6 ppm, respectively. The carbaryl-piperonyl butoxide synergist ratios for the larvae were estimated to range between 1.57–2.17. Alfalfa pollen provided the best larval growth. Pollens from goatsrue, sweet clover, and goldenweed were less satisfactory.

Chlorcyclizine and SKF 525A Effects on Parathion Toxicity and Midgut Tissue Structure in Alkali Bees, Nomia melanderi1

The organophosphate insecticides, parathion, monocrotophos, dicrotophos, and Gardona® [2-chloro-1-(2,4,5-trichlorophenyl) vinyl dimethylphosphate], were highly toxic to adult alkali bees, Nomia melanderi Cockerell. The topical LD 50 values for these ranged from 0.83 (monocrotophos) to 2.69 (Gardona) micrograms per gram of bees. Two carbamate insecticides, however, were much less toxic. The LD 50 values for these ranged from 47.90 [Landrin® (4:1 mixture of 3,4,5– and 2,3,5–isomers of trimethylphenyl methylcarbamate)] to 86.37 (carbaryl) micrograms per gram of bees. The alkali bees were fed and topically treated with the drugs SKF 525A (2-diethylaminoethyl 2,2-diphenyl pentanoate) and chlorcyclizine [ N -methyl- N -(4-chlorbenzhydryl) piperazine] to determine if they could protect the bees from parathion. Chlorcyclizine made the bees generally more susceptible, whereas SKF 525A either had no effect or protected one sex without protecting the other. The protective effects with SKF 525A were small as well as inconsistent and therefore such drug treatments probably have little potential for protecting alkali bees from parathion in the field. Electron micrographs of the gut tissue of the insects showed that chlorcyclizine and SKF 525A had significant effects upon the cellular ultrastructure. Some of these effects were similar to those observed in other insects treated with different drugs in which detoxication measurements or biological assay tests had shown that the drug had limited potential for induction of protective detoxication mechanisms.

Biology and Control of the Spruce Needleminer12

Taniva albolineana (Kearfott), considered to be a relatively minor pest of spruce, was a serious pest of young Black Hills spruce, Picea glauca var. densata Bailey, in nurseries during 1970–72. Foliar sprays of several insecticides applied during July were effective in controlling this insect. The compounds and rates of AI/100 gal water were carbaryl at 0.5 and 1.0 lb, diazinon at 0.25 and 0.5 lb, dimethoate at 0.15 and 0.3 lb, trichlorfon at 1.0 lb, and Gardona® (2-chloro-l-[2,4,5-trichlorophenyl]vinyl dimethyl phosphate) at 1.0 lb.

Differential response of plant cell membranes to some vinyl organophosphorus insecticides

The response of plant cell membranes to vinyl organophosphorus insecticides was studied by determining the release of intracellular materials as a measure of membrane permeability and the uptake of [1- 14C]-α-aminoisobutyric acid as a measure of active transport. A pretreatment with chlorfenvinphos (2-chloro-1-(2,4-dichlorophenyl)-vinyl diethyl phosphate) at 0.4 m M or higher concentrations increased the leakage of cell contents from the tissues of pea, corn, and beet, but two other vinyl organophosphorus insecticides, tetrachlorvinphos (2-chloro-1-(2,4,5-trichlorophenyl)-vinyl diethyl phosphate) and phosphamidon (2-chloro-2-diethyl carbamoyl-1-methyl vinyl dimethyl phosphate), had no effect. Simultaneous addition of phospholipids, β-sitosterol, or Ca 2+ inhibited in varying degrees the chlorfenvinphos-induced permeability, suggesting that the leakage of cell contents might be due to alteration in membrane structure. Chlorfenvinphos or tetrachlorvinphos at 0.1 m M or higher concentrations inhibited the uptake of α-aminoisobutyric acid. The degree of inhibition varied with different plant species. The inhibition was competitive and was not prevented by phospholipids. However, Ca 2+ and other divalent cations were stimulatory to the uptake of α-aminoisobutyric acid, either in the presence or absence of chlorfenvinphos. Chlorfenvinphos also inhibited plant growth in tobacco callus and pea stem assays. From the differences in effective concentration, structural requirement, and interaction with phospholipids, it is suggested that chlorfenvinphos affected the membrane permeability and active transport by different mechanisms. These effects probably underlie its inhibitory action on plant growth.

Spodoptera frugiperda Chemical Control in Paddy by Using Ultra-Low-Volume Drift Spraying1

The fall armyworm, Spodoptera frugiperda (J. E. Smith), is a serious pest of young paddy crop in Guyana. Comparative toxicity of 35 insecticides to 4-to 5-day-old armyworms was worked out. Eight insecticides, comparatively more toxic than the rest, were further tested for their relative toxicity. At LC50 fenitrothion, azinphosmethyl, lodofenphos [ O -(2,5-dichloro-4-iodophenyl) O, O -dimethyl phosphorothioate], phoxim, methomyl, Gardona® [2-chloro-1-(2,4,5-tricholorophenyl)vinyl dimethyl phosphate, and American Cyanamid CL-47470 [cyclic propylene P, P -diethyl phosphonodithiomidocarbonate] were 12.1, 8.1, 5.4, 3.3, 2.8, 1.7 and 1.4 times respectively more toxic than Chlofenvinphos [2-chloro-1-(2,4-dichlorophenyl)-vinyl diethyl phosphate]. In field trials, fenitrothion emulsion spray at 120-185 g AI/ha controlled the armyworm infesting up to 5-week-old paddy. With natural wind velocity of 10-15 km/h drift spraying could be carried out using a motorized knapsack sprayer fitted with a low-volume attachment. The drift swath was 9 m, and 3.5 liters of spray fluid was required per hectare. It took about 21 min to treat 1 ha of paddy.

Abatement of yellowjackets using encapsulated formulations of diazinon and rabon.

Abatement of Vespula pensylvanica (Saussure) and V. rulgaris (L.), using encapsulated formulations of diazinon (0.5%) and Rabon® (2 chloro-1-(2,4,5-triehlorophenyl) vinyl dimethyl phosphate) (0.75%), in 9-Lives® tuna (for cats), was demonstrated at 8 test sites in northern California in 1971 and 1972. Foraging yellow jackets were reduced an estimated 75-95% after only 2 days of exposure to bait. Subsequent treatments were needed 10 days later to control yellowjackets that received no toxicant initially. Varying amounts of diazinon in dead yellow jackets, according to stage of development, were recovered from 2 ground nests by chemical analyses. Rabon and diazinon are highly repellent to yellow jackets, even at low concentrations. Encapsulation masks the chemical odor emitted by the insecticides, but it does not, alter their effectiveness as control agents.

Feeding of coumaphos, ronnel, and Rabon to dairy cows: larvicidal activity against hous flies and effect on insect fauna and biodegradation of fecalpats.

Eight dairy cows 2/treatment, were fed a concentrate—alfalfa hay pellet-corn silage ration supplemented as follows (1) no insecticide, (2) 56 ppm coumaphos, (3) 56 ppm Rabon® (2-ehloro-1-[2,4,5-trichlorophenyl] vinyl dimethyl phosphate), or (4) 112 ppm ronnel. Larvicidal activity against Musca domestica L. was significantly greater in feces from cows fed Rabon than in feces from cows fed either coumaphos or ronnel. Milk from cows fed coumaphos or Rabon contained no residues (<0.005 ppm), however, residues were detected in milk from cows fed ronnel. Feces examined after 6 or 9 weeks in a pasture showed no difference between the biodegradation of untreated and treated feces except that little tunneling was observed in the pats containing coumaphos. This tunneling was apparently done by larvae of soldier fly, Sargus cuparius (L.).