Inhibitory Effects of Turf Pesticides on Bacillus popilliae and the Prevalence of Milky Disease

Fourteen pesticides (fungicides, herbicides, and insecticides) were tested to determine whether they had deleterious effects on the bioinsecticide Bacillus popilliae, the causal agent of milky disease. All of these pesticides reduced levels of spore viability, spore germination, and/or vegetative cell growth when they were tested over a range of concentrations from 0 to 1,000 ppm of active ingredient, and the fungicides had the greatest detrimental effects. As determined by tests in water, the level of spore viability was significantly reduced by chlorothalonil, iprodione, (2,4-dichlorophenoxy)acetic acid plus 2-(2,4-dichlorophenoxy)propionic acid, and 2-[(4-chloro-o-tolyl)oxy]propionic acid plus (2,4-dichlorophenoxy)acetic acid. In tests performed with iprodione, loss of viability was evident at concentrations less than the concentration calculated to result from recommended use. Tests performed in soil demonstrated that triadimefon, chlorothalonil, (2,4-dichlorophenoxy)acetic acid plus 2-(2,4-dichlorophenoxy)propionic acid, and pendimethalin at concentrations resulting from recommended rates of application reduced spore titers. Spore germination did not occur in the continued presence of 2-[(4-chloro-otolyl)oxy]propionic acid plus (2,4-dichlorophenoxy)acetic acid, isofenphos, and chlordane, whereas exposure of spores to triadimefon or pendimethalin for 2 days stimulated germination. The tests to determine effects on spore germination were inconclusive for all other pesticides. Triadimefon, chlorothalonil, iprodione, pendimethalin, and chlorpyrifos at concentrations less than the concentrations recommended for use inhibited vegetative cell growth of B. popilliae, and chlordane at a concentration that was twice the concentration expected to result from the recommended rate of application repressed cell growth. My data support the hypothesis that use of synthetic pesticides can contribute to a low incidence of milky disease in white grubs.     

The effect of iprodione on the seed-borne phase of Alternaria brassicicola

Alternaria brassicicola infection of Brassica oleracea seeds was effectively controlled by a dust application of iprodione (Rovral 50% w.P.). At 2.5 g a.i./kg the seed-borne fungus was usually eliminated from samples with up to 61.5% affected seeds (35.5% internally diseased) but higher levels of infection required increased doses for complete eradication of the fungus. The germination of healthy seeds, including samples from 7–yr-old stocks, on filter paper was unaffected by the treatment. However, the germination of diseased samples, particularly those internally infected with A. brassicicola, was improved. More seedlings emerged from iprodione treated than from untreated seeds in glasshouse soil but the differences were not significant. The application of gamma-hexachlorocyclohexane to iprodione treated seeds sown in soil did not adversely affect subsequent emergence or disease control. Disease control was maintained and germination was not affected by the treatment when treated infected seeds were stored for 2 yr at 10 °C, 50% r.h. In a field trial iprodione seed treatment reduced seedling infection in a cabbage crop grown from naturally diseased seeds (100% contaminated, 45.5% internally infected) from 5.6 to 0.04%.     

Induction of blastocladiella emersonii germination by cyclic adenosine-3′, 5′-monophosphate

The role of adenosine 3′,5′-monophosphate (cyclic AMP) in the control of Blastocladiella emersonii germination was studied. This differentiative transition may be induced by replacing K⁺, a classical inducer, by cyclic AMP or by competitive inhibitors of cyclic AMP phosphodiesterase activity. When zoospores are treated simultaneously with two inducers at non-effective concentrations, a synergistic effect is observed between cyclic AMP and either KCl or adenine. The calcium ionophore A23187 per se is not able to elicit germination, but the association of A23187 and sub-optimal concentrations of cyclic AMP is effective. These results suggest that germination may depend on a correlation between the intracellular mobilization of calcium and cyclic AMP levels.     

Sclerotia of Botrytis as a Source of Primary Inoculum for Bunch Rot of Grapes in New South Wales, Australia

Sclerotia of Botrytis cinerea were found to be a source of primary inoculum for bunch rot of grapes in the Hunter Valley of New South Wales. Conidia-bearing sclerotia were found on canes on grapevines. Resporulation of sclerotia was observed and sporogenic germination led to infection of flowers and berries. Sclerotia survived for eight months in untreated soil in the laboratory. Application of dicarboximides (procymidone, iprodione and vinclozolin) reduced infection of flowers and bunch rotcaused by the sporogenic germination of sclerotia.     

Alteration of the binding constants of malathion and carbaryl to cytochrome P-450 due to hydrolysis by rat hepatic microsomal esterases

During studies to determine spectral binding properties of malathion and carbaryl to rat liver microsomal cytochrome P-450, it was observed that final concentrations of 5 μM malathion and 10 μM carbaryl produced unstable binding spectra. Evidence is presented which demonstrates that a major reason for the unstable binding spectra of these insecticides is rapid degradation by hepatic microsomal esterases. In this respect, carbaryl and malathion, and possibly other compounds that contain ester linkages, appear to be unique, since most compounds are not metabolized under the conditions in which binding spectra are determined, i.e. in the absence of an NADPH generating system.     

Colonization by Arbuscular Mycorrhizal Fungi of Sorghum Leads to Reduced Germination and Subsequent Attachment and Emergence of Striga hermonthica

Two sorghum cultivars: the Striga-tolerant S-35 and the Striga-sensitive CK60-B were grown with or without arbuscular mycorrhizal (AM) fungi, and with or without phosphorus addition. At 24 and 45 days after sowing (DAS) of sorghum, root exudates were collected and tested for effects on germination of preconditioned Striga hermonthica seeds. Root exudates from AM sorghum plants induced lower germination of S. hermonthica seeds than exudates from non-mycorrhizal sorghum. The magnitude of this effect depended on the cultivar and harvest time. A significantly (88–97%) lower germination of S. hermonthica seeds upon exposure to root exudates from AM S-35 plants was observed at both harvest times whereas for AM inoculated CK60-B plants a significantly (41%) lower germination was observed only at 45 DAS. The number of S. hermonthica seedlings attached to and emerged on both sorghum cultivars were also lower in mycorrhizal than in non-mycorrhizal plants. Again, this reduction was more pronounced with S-35 than with CK60-B plants. There was no effect of phosphorus addition on Striga seed germination, attachment or emergence. We hypothesize that the negative effect of mycorrhizal colonization on Striga germination and on subsequent attachment and emergence is mediated through the production of signaling molecules (strigolactones) for AM fungi and parasitic plants.Key Words: arbuscular mycorrhiza, root exudate, sorghum, striga, strigolactones, germination     

Fungicide resistance of Botrytis cinerea in tomato greenhouses in the Canary Islands and effectiveness of non-chemical treatments against gray mold

Tomato greenhouses in the Canary Islands, Spain, were surveyed to estimate frequencies of resistance to benzimidazoles, dicarboximides, anilinopyrimidines and N-phenylcarbamates in Botrytis cinerea. Resistance to carbendazim, iprodione, pyrimethanil and diethofencarb was found in 74.2, 86.4, 28.8 and 31.8 % of isolates, respectively. Benzimidazole- and anilinopyrimide-resistant isolates were highly resistant, showing EC₅₀ values above 500 µg/ml carbendazim and a mean EC₅₀ value of 28.42 µg/ml pyrimethanil, respectively. By contrast, a low level of resistance was observed among dicarboximide-resistant isolates (mean EC₅₀ value of 1.81 µg/ml iprodione). Phenotypes with double resistance to carbendazim and iprodione, and triple resistance to carbendazim, iprodione and pyrimethanil were the most common, occurring in 36.4 and 28.8 % of isolates. The surveyed greenhouses had never been treated with fenhexamid and Signum? (pre-packed mixture of boscalid and pyraclostrobin), and baseline sensitivities of B. cinerea isolates to these fungicides were determined. The EC₅₀ values were within the range of 0.009–0.795 µg/ml fenhexamid and of 0.014–0.48 µg/ml Signum. In addition, available formulations based on elicitors of plant defense response and biocontrol agents were evaluated against B. cinerea in tomato plants under semi-controlled greenhouse conditions, the yeast Candida sake CPA-1 being able to reduce gray mold significantly when it was applied on petiole wounds and the plants were inoculated 24 h later. Likewise, C. sake was effective against B. cinerea in harvested tomato fruits, yeast-treated tomatoes showed a 70.66 and 30.31 % reduction in the diameters of decay lesions compared with controls after 10 days of storage at 20 and 9 °C, respectively.     

Impact of fungicides on Metarhizium anisopliae in the rhizosphere, bulk soil and in vitro

The entomopathogenic fungus Metarhizium anisopliae (Metchnikoff) Sorokin (Hypocreales: Clavicipitaceae) is registered in the United States and The Netherlands for black vine weevil, Otiorhynchus sulcatus (Coleoptera: Curculionidae) control in container-grown ornamentals. These studies were conducted to determine the compatibility of M. anisopliae (F52) with a wide range of fungicides commonly applied to container-grown ornamentals for the management of soil-borne plant pathogens. The impact of fungicides on spore germination and mycelial growth were determined in vitro. In addition, M. anisopliae persistence in bulk and rhizosphere soil was determined 30 days following dual application of each fungicide at 7–28 days intervals as prescribed. A number of fungicides (thiophanate-methyl, dimethomorph, captan, triflumizole, triflozystrobin, pyraclostrobin, azoxystrobin) inhibited spore germination in vitro. A larger number of fungicides (fosetyl-AI, thiophanate-methyl, dimethomorph, captan, quintozene, triflumizole, fludioxanil, triflozystrobin, pyraclostrobin, fludiox-mefanox, iprodione, azoxystrobin, phosphorus acid/K-salts) inhibited mycelial growth in vitro. Only three fungicides (etridiazole, propamocard and mafanoxam) had no significant impact in vitro on spore germination or mycelial growth. While a number of fungicides had a detrimental impact in vitro, there was no impact on M. anisopliae populations in bulk soil following dual application of any fungicide. However, the fungicides captan and triflumizolet, which have a short reapplication interval, had a detrimental impact on M. anisopliae populations in the rhizosphere. As researchers develop rhizosphere competence as an alternative management strategy for black vine weevil, the fungicides captan and triflumizole should be avoided.     

Synergistic effect of fumigation with ethyl formate and methyl salicylate on mortality of life stages of adzuki bean beetle,Callosobruchus chinensis (L.)

Ethyl formate (EF) is becoming an insecticide of choice for protecting stored commodities. Along with EF, methyl salicylate (MS) is also naturally occurring, and both are generally regarded as safe fumigants for their higher threshold limit values (TLV) and residual status below minimum residue limit (MRL). Sub-lethal doses of EF and MS were evaluated to determine if there was a synergistic effect on fumigation against life stages of the adzuki bean beetle, Callosobruchus chinensis (L.) infesting adzuki bean grains. Based on lethal dose (LD) values, the C. chinensis eggs and adults were equally susceptible to EF followed by larvae and pupae. Adults were the most MS-sensitive followed by eggs and larvae, and pupae were the most tolerant stage. The mortalities of all the life stages of C. chinensis by combined fumigation with sub-lethal EF and MS doses were significantly higher compared to the sum of their separate fumigations revealing a notable synergistic effect. Moreover, the maximum doses of EF and MS tested for synergistic fumigation test did not hamper the germination potential of adzuki been seeds. The synergistic effect between EF and MS can significantly reduce the dose rate of flammable EF against C. chinensis thereby offering a good prospect for EF + MS formulation as an alternative to safeguard stored adzuki bean.     

Additive and synergistic effects of kinetin and ethrel on germination, thermodormany, and polyribosome formation in lettuce seeds

The inhibition of germination of Grand Rapids lettuce (Lactuca sativa L.) seeds at 35 C was removed to a marked extent by kinetin and 2-chloroethylphosphonic acid (ethrel). When both compounds were used together, an additive effect was observed. A synergistic effect was, however, noted when ethrel promoted the kinetin reversal of abscisic acid inhibition of seed germination (light- as well as gibberellic acid-, induced). Both kinetin and ethrel increased the total ribosomal material and the percentage of polyribosomes in lettuce seeds imbibed in the light for 24 hours. A combination of the two compounds showed a synergism in polyribosome formation only at high ethrel concentration. The inability of ethrel to reverse abscisic acid inhibition indicates that kinetin action cannot always be substituted by ethrel. The possible mechanisms involved in the enhanced response by a combination of kinetin and ethrel are discussed.     

Investigation of kinetic interactions between approved oximes and human acetylcholinesterase inhibited by pesticide carbamates

Carbamates are widely used for pest control and act primarily by inhibition of insect and mammalian acetylcholinesterase (AChE). Accidental or intentional uptake of carbamates may result in typical signs and symptoms of cholinergic overstimulation which cannot be discriminated from those of organophosphorus pesticide poisoning. There is an ongoing debate whether standard treatment with atropine and oximes should be recommended for human carbamate poisoning as well, since in vitro and in vivo animal data indicate a deleterious effect of oximes when used in combination with the N-methyl carbamate carbaryl. Therefore, we performed an in vitro kinetic study to investigate the effect of clinically used oximes on carbamoylation and decarbamoylation of human AChE. It became evident that pralidoxime and obidoxime in therapeutic concentrations aggravate the inhibition of AChE by carbaryl and propoxur, with obidoxime being substantially more potent compared to 2-PAM. However, obidoxime had no impact on the decarbamoylation kinetics. Hence, the administration of 2-PAM and especially of obidoxime to severely propoxur and carbaryl poisoned humans cannot be recommended.     

Insecticide effects onEntomophthora muscae [Zygomycetes: Entomophthorales]

Studies were conducted to determine the effect of insecticide residues on germination of primary conidia ofentomophthora muscae (Cohn) Fresenius and to determine the relative susceptibility of healthy and infectedMusca domestica L. to insecticides. Primary conidia were discharged fromM. domestica cadavers onto glass microscope slides treated with insecticides. All insecticides significantly inhibited germination relative to control slides. Permethrin and naled had the least inhibition (36–40 %), while malathion and dimethoate almost completely inhibited germination (87–94 %). Tetrachlorvinphos/dichlorvos and carbaryl were intermediate (57–59 %). Healthy flies were not significantly different from infected flies in terms of susceptibility to naled, dimethoate, or permethrin. Infected flies exposed on the last day of pathogen incubation died on the bottom of the Petri dishes, rather than climbing and attaching as did untreated, infected flies. Both control and treated groups produced large numbers of primary conidia.     

Nutrient enrichment in the High Arctic associated with Thule Inuit whalers: a paleolimnological investigation from Ellesmere Island (Nunavut,Canada)

The combined influence of a pesticide (carbaryl) and a cyanotoxin (microcystin LR) on the life history of Daphnia pulicaria was investigated. At the beginning of the experiments animals were pulse exposed to carbaryl for 24 h and microcystins were delivered bound in Microcystis’ cells at different, sub-lethal concentrations (chronic exposure). In order to determine the actual carbaryl concentrations in the water LC–MS/MS was used. For analyses of the cyanotoxin concentration in Daphnia’s body enzyme-linked immunosorbent assay (ELISA) was used. Individual daphnids were cultured in a flow-through system under constant light (16 h of light: 8 h of dark), temperature (20°C), and food conditions (Scenedesmus obliquus, 1 mg of C l⁻¹). The results showed that in the treatments with carbaryl egg numbers per female did not differ significantly from controls, but the mortality of newborns increased significantly. Increasing microcystin concentrations significantly delayed maturation, reduced size at first reproduction, number of eggs, and newborns. The interaction between carbaryl and Microcystis was highly significant. Animals matured later and at a smaller size than in controls. The number of eggs per female was reduced as well. Moreover, combined stressors caused frequent premature delivery of offspring with body deformations such as dented carapax or an undeveloped heart. This effect is concluded to be synergistic and could not be predicted from the effects of the single stressors.     

Synergistic enhancement of ethylene production and germination with kinetin and 1-aminocyclopropane-1-carboxylic Acid in lettuce seeds exposed to salinity stress

Relief of salt (0.1 molar NaCl) stress on germination of lettuce (Lactuca sativa L., cv Mesa 659) seeds occurred with applications of 0.05 millimolar kinetin (KIN) and 1 to 10 millimolar 1-aminocyclopropane 1-carboxylic acid (ACC). Treatment with KIN enhanced the pregermination ethylene production under saline condition. A synergistic or an additive enhancement of pregermination ethylene production and germination occurred under saline condition in the presence of KIN and a saturating dose (10 millimolar) of ACC. No KIN-ACC synergism was noted in ethylene production or germination under nonsaline condition. Addition of 1 millimolar aminoethoxyvinylglycine (AVG) inhibited the KIN-enhanced pregermination ethylene production (85 to 89%) and germination (58%) under saline condition but not the synergistic effect of KIN + ACC on ethylene production. Under nonsaline condition, AVG had no effect on germination even though ethylene production was strongly inhibited. Alleviation of salt stress by KIN was inhibited in a competitive manner by 2,5-norbornadiene (NBD) (0.02-0.2 milliliter per liter), and the addition of ACC and/or ethylene reduced this inhibition. An increase in the pregermination ethylene production and germination occurred also by cotylenin E (CN) under saline condition. However, neither AVG (1 millimolar) nor NBD (0.02 to 0.2 milliliter per liter) prevented the relief of salt stress by CN. Thus, KIN may alleviate salt stress on germination by promoting both ACC production and its conversion to ethylene. Rapid utilization of ACC may be the basis for the synergistic or the additive effect of KIN plus ACC. The need for ethylene production and action for the relief of salt stress is circumvented by a treatment with CN.     

Chemical composition of essential oils of four Eucalyptus species and their phytotoxicity on silverleaf nightshade (Solanum elaeagnifolium Cav.) in Australia

Phytotoxicity and chemical composition of essential oils from four selected Eucalyptus species in Australia were investigated. Essential oils had stronger inhibitory effects on germination and seedling growth of silverleaf nightshade (Solanum elaeagnifolium Cav.) when compared with a commercial eucalyptus oil and with 1,8-cineole. E. salubris oil had the highest inhibition index for silverleaf nightshade germination, root growth and shoot growth, while E. spathulata had the lowest inhibitory effect except root growth. Gas chromatography-mass spectrometry analysis revealed 56 compounds present in E. salubris oil, with 1,8-cineole (57.6?%), ??-pinene (10.9?%) and p-cymene (8.3?%) predominant. E. dundasii oil contained 55 identified compounds with 1,8-cineole (65.5?%) and ??-pinene (19.9?%) being the richest fractions. There were 56 compounds identified from E. brockwayii oil with ??-pinene (31.1?%), isopentyl isovalerate (20.2?%) and 1,8-cineole (16.9?%) as the most abundant components. E. spathulata oil contained 60 compounds, predominantly 1,8-cineole (52.9?%) and ??-pinene (31.0?%). Further study is required to determine the phytoxicity of the individual identified compounds on silverleaf nightshade and whether the observed phytotoxicity is attributable to a single compound or to the synergistic effects of several compounds.     

Metabolism of Carbaryl via 1,2-Dihydroxynaphthalene by Soil Isolates Pseudomonas sp. Strains C4, C5, and C6

Pseudomonas sp. strains C4, C5, and C6 utilize carbaryl as the sole source of carbon and energy. Identification of 1-naphthol, salicylate, and gentisate in the spent media; whole-cell O₂ uptake on 1-naphthol, 1,2-dihydroxynaphthalene, salicylaldehyde, salicylate, and gentisate; and detection of key enzymes, viz, carbaryl hydrolase, 1-naphthol hydroxylase, 1,2-dihydroxynaphthalene dioxygenase, and gentisate dioxygenase, in the cell extract suggest that carbaryl is metabolized via 1-naphthol, 1,2-dihydroxynaphthalene, and gentisate. Here, we demonstrate 1-naphthol hydroxylase and 1,2-dihydroxynaphthalene dioxygenase activities in the cell extracts of carbaryl-grown cells. 1-Naphthol hydroxylase is present in the membrane-free cytosolic fraction, requires NAD(P)H and flavin adenine dinucleotide, and has optimum activity in the pH range 7.5 to 8.0. Carbaryl-degrading enzymes are inducible, and maximum induction was observed with carbaryl. Based on these results, the proposed metabolic pathway is carbaryl → 1-naphthol → 1,2-dihydroxynaphthalene → salicylaldehyde → salicylate → gentisate → maleylpyruvate.     

Nucleotide Sequence and Genetic Structure of a Novel Carbaryl Hydrolase Gene (cehA) from Rhizobium sp. Strain AC100

Rhizobium sp. strain AC100, which is capable of degrading carbaryl (1-naphthyl-N-methylcarbamate), was isolated from soil treated with carbaryl. This bacterium hydrolyzed carbaryl to 1-naphthol and methylamine. Carbaryl hydrolase from the strain was purified to homogeneity, and its N-terminal sequence, molecular mass (82 kDa), and enzymatic properties were determined. The purified enzyme hydrolyzed 1-naphthyl acetate and 4-nitrophenyl acetate indicating that the enzyme is an esterase. We then cloned the carbaryl hydrolase gene (cehA) from the plasmid DNA of the strain and determined the nucleotide sequence of the 10-kb region containing cehA. No homologous sequences were found by a database homology search using the nucleotide and deduced amino acid sequences of the cehA gene. Six open reading frames including the cehA gene were found in the 10-kb region, and sequencing analysis shows that the cehA gene is flanked by two copies of insertion sequence-like sequence, suggesting that it makes part of a composite transposon.     

Tolerance and recovery responses of playa halophytes to light,salinity and temperature stresses during seed germination

Halogeton glomeratus (M. Bieb.) C.A. Mey., Lepidium latifolium Linn. and Peganum harmala Linn. are distributed in temperate salt playa habitats of Upper Hunza, Pakistan. Seeds were germinated under various salinity (0–500 mM NaCl), light (12 h-light:12 h-dark and 24 h-dark) and temperature (5/15, 10/20, 15/25, 20/30, and 25/35 °C, dark/light) regimes for 20 days to determine the optimal conditions for germination and recovery of seeds from these factors when exposed to less than optimal conditions. Seeds that failed to germinate in dark were transferred successively to 12 h-photoperiod, salinity to distilled water and from various temperature regimes to 20/30 °C, to determine the effect of these stresses and the ability of these seeds to recover respectively. Highest seed germination (H. glomeratus and L. latifolium: 100%; P. harmala: 80%) was obtained in non-saline control at 20/30 °C in 12 h-photoperiod, however, increase in salinity progressively inhibited seed germination. Seed germination of H. glomeratus and P. harmala was substantially inhibited and that of L. latifolium was prevented in dark. Salinity and dark treatments have a synergistic effect in inhibiting seed germination of all species. No seed of any species germinated at 5/15 °C; germination was substantially inhibited at 25/35 °C both for H. glomeratus and P. harmala while L. latifolium failed to germinate at 25/35 °C. Rate of germination also decreased with an increase in salinity at all temperature regimes but this effect was minimal at optimal temperature regime of 20/30 °C. After successive elimination of light, salinity and temperature stresses, final seed germination was identical to respective controls. The results indicate that seeds of these temperate halophytes could endure environmental stresses without losing viability and germinate readily when these stresses are removed. Under the extremely variable conditions of the playa habitat these species are highly opportunistic exploiting the windows of opportunity available during spring or early summer.     

No evidence for a cost of selection by carbaryl exposure in terms of vulnerability to fish predation in <Emphasis Type="Italic">Daphnia magna</Emphasis>

Natural populations are exposed to multiple stressors. These stressors may interact, leading to synergistic or antagonistic responses. In addition to these direct interaction effects, there may also be an interaction between stressors through a selection effect: as the population genetically responds to one stressor, it may become more vulnerable to another one, for instance because of an associated reduction in genetic variation. We here capitalized on a selection experiment involving the exposure of Daphnia populations to carbaryl pulses to test the hypothesis that selection imposed by this pesticide may increase vulnerability to fish predation in the resulting population. A direct predation experiment with individuals isolated from carbaryl-exposed and non-exposed populations revealed no effect of prior selection by carbaryl exposure on mortality due to stickleback predation.     

Glutathione reductase and catalase as potential biomarkers for synergistic intoxication of pesticides in fish

Abstract

Synergy occurs when chemicals give pronounced effect on combination in contrast to their individual effect. The objective of this study was to investigate the synergistic effect of pesticides carbaryl (C) and methyl parathion (MP) on oxidative stress biomarkers viz catalase (CAT), glutathione reductase (GSSG-R) including different enzymes like lactate dehydrogenase (LDH), succinate dehydrogenase (SDH) and acetyl cholinesterase (AChE) in different tissues of carps Catla catla. Fishes were exposed to 6.25?mg/L of MP and 2.3?mg/L of C in mixture (one-third of LC₅₀ value). CAT and GSSG-R were studied in gills, brain, liver and muscle of carp were found to be elevated significantly (p?<?0.005). LDH activity increased significantly (p?<?0.005) in synergistic group, there was a seven-fold (748%) increase in LDH activity in muscle compared to individual studies with same pesticides. Contrary to LDH, sudden decrease in SDH activity was accounted. Significant (p?<?0.005) decrease in AChE activity after initial 24?h was remarkable addressing to the shift in neurotransmission pathway in organism. Significant increase was observed in activity of CAT and GSSG-R in all tissues compared to control fishes in individual as well as synergistic (MP?+?C) group suggesting that CAT and GSSG-R can be a potential biomarker of oxidative stress when studied in combination.