Presence Of Deltamethrin Research Articles

Laboratory Evaluation of the Combine Usage Possibilities of Entomopathogenic Nematodes with Insecticides against Mediterranean Corn Borer Sesamia nonagrioides (Lefebvre)

The Mediterranean Corn Borer (MCB), Sesamia nonagrioides, poses a significant threat to maize crops, necessitating effective pest management strategies. This study investigates the compatibility of two entomopathogenic nematode (EPN) isolates, Steinernema feltiae KV6 and Heterorhabditis bacteriophora EO7, with four registered insecticides for MCB control: deltamethrin, flubendiamide, spinetoram, and betacyfluthrin. The impact of these insecticides on EPN mortality, infectivity, and reproduction was assessed. Results indicate that deltamethrin exhibits the lowest toxicity to EPNs, with mortality rates of 1.3% for S. feltiae and 0.63% for H. bacteriophora at field dose (FD) after 24 h and 4.63% and 1.96%, respectively, after 48 h. In contrast, betacyfluthrin showed higher toxicity, with mortality rates of 38.04% and 14.17% for S. feltiae at 2FD and FD after 48 h. The infectivity assays demonstrated that deltamethrin-treated EPNs caused up to 100% mortality in MCB larvae, while the reproduction capacity varied significantly between the EPN species and insecticides. H. bacteriophora exhibited higher progeny production, especially in the presence of deltamethrin (87,900 IJs/larva). The findings suggest that integrating EPNs with selective insecticides like deltamethrin can enhance pest control efficacy and support sustainable agricultural practices. This study provides valuable insights for developing integrated pest management (IPM) strategies aimed at mitigating MCB infestations in maize while minimizing environmental impacts.

Characterization in Potent Modulation on Voltage-Gated Na+ Current Exerted by Deltamethrin, a Pyrethroid Insecticide

Deltamethrin (DLT) is a type-II pyrethroid ester insecticide used in agricultural and domestic applications as well as in public health. However, transmembrane ionic channels perturbed by this compound remain largely unclear, although the agent is thought to alter the gating characteristics of voltage-gated Na+ (NaV) channel current. In this study, we reappraised whether and how it and other related compounds can make any further modifications on voltage-gated Na+ current (INa) in pituitary tumor (GH3) cells. Cell exposure to DLT produced a differential and dose-dependent stimulation of peak (transient, INa(T)) or sustained (late, INa(L)) INa; consequently, the EC50 value required for DLT-stimulated INa(T) or INa(L) was determined to be 11.2 or 2.5 μM, respectively. However, neither the fast nor slow component in the inactivation time constant of INa(T) activated by short depolarizing pulse was changed with the DLT presence; conversely, tefluthrin (Tef), a type-I pyrethroid insecticide, can accentuate INa with a slowing in inactivation time course of the current. The INa(L) augmented by DLT was attenuated by further application of either dapagliflozin (Dapa) or amiloride, but not by chlorotoxin. During pulse train (PT) stimulation, with the Tef or DLT presence, the cumulative inhibition of INa(T) became slowed; moreover, following PT stimuli, a large tail current with a slowly recovering process was observed. Alternatively, during rapid depolarizing pulse, the amplitude of INa(L) and tail INa (INa(Tail)) for each depolarizing pulse became progressively increased by adding DLT, not by Tef. The recovery time constant following PT stimulation with continued presence of Tef or DLT was shortened by further addition of Dapa. The voltage-dependent hysteresis (Hys(V)) of persistent INa was differentially augmented by Tef or DLT. Taken together, the magnitude, gating, frequency dependence, as well as Hys(V) behavior of INa exerted by the presence of DLT or Tef might exert a synergistic impact on varying functional activities of excitable cells in culture or in vivo.

Colorimetric Measurement of Deltamethrin Pesticide Using a Paper Sensor Based on Aggregation of Gold Nanoparticles

Deltamethrin (DEL) is one of the most commonly used pyrethroid pesticides that can cause serious harms to the ecological environment and human health. Herein, we have developed a paper-based colorimetric sensor impregnated with gold nanoparticles (AuNPs) for on-site determination of DEL pesticide. AuNPs show obvious color change on paper device with the presence of DEL. Measuring the gray intensity of the AuNPs on the reaction zone of the paper sensor allows accurate quantitative analysis. The detection mechanism of DEL on paper sensor was confirmed by UV-Vis spectrophotometry (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscope (TEM). Under optimal conditions, the colorimetric sensor exhibited high sensitivity, rapid detection, and low detection limit within the values stipulated by Chinese detection standards (LOD = 0.584 mg/L). Besides, detecting DEL in vegetable and fruit samples also gave satisfying results, which were much consistent with those obtained by spectrophotometry. Overall, this work provided a user-friendly, cost-effective and visualized detection platform, which could be applied to rapidly detect DEL pesticides in the food safety field.

Effects of exposing shrimp larvae (Pandalus borealis) to aquaculture pesticides at field relevant concentrations, with and without food limitation

Anti-parasitic drugs used in the aquaculture industry are discharged to the sea after treatment of salmon. In this study, the effects of azamethiphos (AZA) in the Salmosan® formulation and deltamethrin (DEL) in the Alpha Max® formulation, have been assessed in Northern shrimp larvae (Pandalus borealis) when administered both separately and in combination. The exposure concentrations were 100 ng/L for AZA and 2 ng/L for DEL, each representing a 1000-fold dilution of the prescribed concentrations for salmon. These two chemicals were combined at these concentrations to give a third treatment (AZA + DEL). When larvae were exposed for two hours on the first, second and third days post hatch (dph), significantly increased mortality and reduced swimming activity were observed for larvae from the DEL and combined AZA + DEL treatments 4 dph, though not in larvae from the AZA treatment. A single pulse exposure, delivered on the first day post hatch, caused similar effects on mortality and swimming activity 4 dph as the three-pulse exposure. Mortality was driven by the presence of DEL in both experiments, with no amplification or reduction of effects observed when DEL and AZA were combined. Larvae were observed for 13 days following the single pulse exposure, with food limitation introduced as an additional stressor on day 4. In the DEL and AZA + DEL treatments mortality continued to increase regardless of food level, with no larvae completing development to stage II. The overriding toxicity of DEL masked any potential effects the reduced food ration may have exerted. Swimming activity was lower for AZA treated larvae than Control larvae 13 dph, when both groups were fed daily, though no other significant changes to mortality, development to stage II, feeding rate or gene expression were observed. Food limited Control and AZA larvae had lower swimming activity and feeding rate than daily fed Control larvae, with expression of pyruvate kinase and myosin genes also downregulated. However, there was no negative effect on survival or successful development to stage II in these treatments. In addition, mesencephalic astrocyte-derived neurotropic factor was downregulated in food limited Control larvae when compared with the daily fed Controls.Results from this study together with reported estimates of dispersion plume concentrations of discharged pesticides indicate that toxic concentrations of deltamethrin could reach shrimp larvae several kilometers from a treated salmon farm.

Evaluation of piperonyl butoxide in enhancing the efficacy of pyrethroid insecticides against resistant Anopheles gambiae s.l. in Ghana

BackgroundMalaria vector control methods involving the use of pyrethroids remain the strategies being used against malaria vectors in Ghana. These methods include the use of long-lasting insecticidal nets and indoor residual spraying in many areas in Ghana. However, there is evidence that pyrethroid resistance is widespread in many areas in Ghana. Synergists have been shown to be useful in inhibiting the enzymes that are responsible for the development of resistance and hence enhance the insecticide susceptibility of Anopheles gambiae sensu lato (s.l.) in many areas. The present study investigated the effect of piperonyl butoxide (PBO) on the susceptibility status of An. gambiae s.l. across some sentinel sites in Ghana.MethodsThree to five day old An. gambiae s.l. reared from larvae were used in WHO susceptibility tube assays. Batches of 20–25 female adult An. gambiae s.l. were exposed simultaneously to the insecticide alone and to the PBO + insecticide. The knock down rate after 60 min and mortality at 24 h were recorded.ResultsDeltamethrin and permethrin resistance of An. gambiae s.l. was observed in all the sites in 2015 and 2016. The mortality after 24 h post exposure for deltamethrin ranged from 16.3% in Weija to 82.3% in Kade, whereas that for permethrin ranged from 3.8% in Gomoa Obuasi to 91.3% in Prestea. A significant increase in susceptibility to deltamethrin and less to permethrin was observed during both 2015 and 2016 years in most of the sites when An. gambiae s.l. mosquitoes were pre-exposed to PBO.ConclusionFindings from this study showed that the use of PBO significantly enhanced the susceptibility of An. gambiae s.l. mosquitoes in most of the sentinel sites. It is recommended that vector control strategies incorporating PBO as a synergist can be effective in killing mosquitoes in the presence of deltamethrin and permethrin resistance.

14C-Prothiofos Residues in the Presence of Deltamethrin and Dimilin Pesticides in Cotton Seeds and Oils, Removal of Prothiofos Residues in Oils and Bioavailability of its Bound Residues to Rats

Ethyl-1-14C-prothiofos and some of its degradation products have been prepared for the present investigation. Cotton plants were treated with 14C-prohiofos alone and in presence of deltamethrin and dimilin pesticides under conditions simulating local agricultural practice. 14C-residues in seeds were determined at harvest time about 75% of 14C-activity was associated with oil. The ethanol soluble 14C-residues accounted for 6% of the total seed residues after further seeds extraction, while the cake contained about 18.5% of the total residues in case of prothiofos only. The bound residues increased in presence of deltamethrin and dimilin pesticides and amounted to 30% and 34% of the total residues, respectively. About 89% of the 14C-activity in the crude oil could be eliminated by simulated commercial processes locally used for oil refining. Chromatographic analysis of cotton oil extracts (acetonitrile layer) revealed the presence prothiofos oxon, O-ethyl phosphorothioate, O-ethyl S-propyl phosphorothioate, des-propylthio prothiofos, O-ethyl phosphoric acid as the main degradation products, besides to one unknown compound in addition to the parent compound, in case of prothiofos alone. The same degradation products are found in case of prothiofos and deltamethrin and prohiofos and dimilin except compounds O-ethyl S-propyl phosphorothioate and des-propylthio prothiofos. Chromatographic analysis of ethanol extract revealed the presence of O-ethyl phosphorothioate, despropylthio prothiofos and O-ethyl phosphoric acid as free metabolites. The conjugated metabolite was liberated by acid hydrolysis and identified as 2,4-dichlorophenole which was detected by color. When rats were fed the extracted cake for 72 hours, the bound residues were found to be bioavailable. The main excretion route was via the expired air (49%), while the 14C-residues excreted in urine and feces were (34% and 9.7%), respectively. The radioactivity detected among various organs accounted to 6.1%. Chromatographic analysis of urine was determined.

Fate of 14C-ethion insecticide in the presence of deltamethrin and dimilin pesticides in cotton seeds and oils, removal of ethion residues in oils, and bioavailability of its bound residues to experimental animals.

Ethyl-1-(14)C-ethion and some of its degradation products have been prepared for comparison purposes. Cotton plants were treated with (14)C-ethion alone and in the presence of deltamethrin and dimilin pesticides under conditions simulating local agricultural practice. (14)C-Residues in seeds were determined at harvest time; about 47.5% of (14)C-activity was associated with oil. After further extraction of seeds with ethanol, the ethanol-soluble (14)C-residues accounted for 10.6% of the total seed residues, whereas the cake contained about 37.3% of the total residues as bound residues in the case of ethion only. The bound residues decreased in the presence of deltamethrin and dimilin pesticides and amounted to 8.1 and 10.4% of the total residues, respectively. About 95% of the (14)C-activity in the crude oil could be eliminated by simulated commercial processes locally used for oil refining. Chromatographic analysis of crude cotton oil revealed the presence of ethion monooxon, O,O-diethyl phosphorothioate, and O,O-diethyl phosphoric acid in addition to one unknown compound in the case of ethion alone or ethion and dimilin. The same degradation products are found in the case of ethion and deltamethrin in addition to ethion dioxon, whereas ethanol extract revealed the presence of ethion dioxon and O,O-diethyl phosphoric acid as free metabolites. Acid hydrolysis of the conjugated metabolites in the ethanol extract yielded O,O-diethyl S-hydroxymethyl phosphorodithioate. The bound residues were quite readily bioavailable to the rats. After feeding rats with the cake containing ethion-bound residues, a substantial amount (60%) of (14)C-residues was eliminated in the urine, whereas the (14)C-residues excreted in expired air and feces were 10 and 9%, respectively. About 11% of the radioactive residues were distributed among various organs.

Protein phosphatase-type 2B is involved in the regulation of the acrosome reaction but not in the temperature-dependent flagellar movement of fowl spermatozoa

The motility and acrosomal integrity of fowl spermatozoa in TES/NaCl buffer, with or without homogenized inner perivitelline layers (IPVL) prepared from laid fowl eggs, was almost negligible at 40 degrees C. However, motility became vigorous even at 40 degrees C when 2 mmol CaCl2/l was added, and the acrosome reaction was also stimulated in the presence, but not in the absence, of IPVL. The presence of deltamethrin or fenvalerate, specific inhibitors of protein phosphatase-type 2B (PP2B), did not permit the restoration of motility at 40 degrees C but, in the presence of IPVL, these compounds stimulated the acrosome reaction in a dose-dependent manner in the range of 1-1000 nmol/l. These results suggest that IPVL is necessary for the activation of the acrosome reaction in fowl spermatozoa and that Ca2+ plays an important role in the stimulation of motility and acrosomal exocytosis. Furthermore, it appears that the intracellular molecular mechanisms for the regulation of the acrosome reaction of fowl spermatozoa are different from those for the restoration of motility, i.e. protein dephosphorylation by PP2B in the former but not in the latter case.

Effects of synthetic pyrethroids and methidation on activities of some digestive enzymes in carp (Cyprinus carpio L.)

The effects of pyrethroid pesticides (deltamethrin, permethrin and cypermethrin) and an organophosphate ester (methidation) on the activities of carp trypsin, α‐chymotrypsin, carboxypeptidase A and lipase were studied. The enzymes were isolated from the gastrointestinal tract and the effects of the pesticides were investigated during incubation for 5 min. The activity of trypsin was influenced only slightly by the presence of deltamethrin and methidation, whereas permethrin and cypermethrin caused significant inhibition. The pyrethroid pesticides at lower concentrations resulted in a slight activation of α‐chymotrypsin. Methidation inhibited the α‐chymotrypsin activity by about 20%. These pesticides modified the lipase activity to a lesser extent; the highest inhibition was measured with cypermethrin. The carboxypeptidase A activity was inhibited by both pyrethroid pesticides and methidation. The results suggest that these pesticides might interact with the active conformation of the studied hydrolytic enzymes, resulting in changes in their activities.

Effect of Deltamethrin Treatment on Lepidopteran Larvae Infected with Baculoviruses Expressing Insect-Selective Toxins μ-Aga-IV, As II, or Sh 1

Abstract Modification of sodium channels by pyrethroids is promoted by channel opening. The insect-specific neurotoxins μ-Aga-IV from the spider Agelenopsis aperta, As II from the sea anemone Anemonia sulcata, and Sh I from the sea anemone Stichadactyla helianthus all increase sodium channel opening and so we tested each of them in combination with deltamethrin for synergistic insecticidal activity. We found that As II increased the insecticidal activity of deltamethrin against the blowfly Lucilia sericata. We also examined the effect of deltamethrin on the infectivity and virulence of Autographa californica nuclear polyhedrosis virus (AcMNPV) and recombinant toxin-expressing viruses in both dose-dependent and time-mortality studies. The recombinant viruses expressed chimeric synthetic genes for μ-Aga-IV, As II, or Sh I (genes mag4, sat2, and ssh1, respectively). When Trichoplusia ni larvae were infected with a LC 20 of the recombinant viruses and treated with a LC 20 of deltamethrin in diet incorporation bioassays, the doses were strictly additive. A cooperative decrease in mortality rate was observed in droplet feeding bioassays when a low dose (LC 20 ) of deltamethrin and high doses of toxin-expressing viruses were fed to larvae but this effect was host-dependent. In T. ni, only wild-type AcMNPV and a recombinant expressing mag4 under very late viral promoter control exhibited reduced times in controlling host feeding and mortality in the presence of deltamethrin. For Heliothis virescens, larvae infected with sat2 -expressing viruses displayed shorter feeding times in the presence of deltamethrin than those infected with virus alone but only at very high virus doses. H. virescens larvae infected with wild-type AcMNPV and a mag4 -expressing recombinant had shorter feeding times and also shorter effective and lethal times in the presence of deltamethrin. Our results indicate that coapplication of this pyrethroid will confer little or no advantage in field applications of recombinant baculovirus pesticides and that application of pyrethroids will probably have no adverse affect on recombinant virus efficacy unless it deters larval feeding and virus acquisition.

Callus tissue of Solanum tuberosum L. cultured in the presence of the pyrethroid deltamethrin

SummaryThe effect of Decis (deltamethrin as active ingredient) on callus tissue of Solanum tuberosum L. cv. Désirée was studied. Decis is an agrochemical currently used on field grown potato plants to control the Colorado beetle, a potato pest. Deltamethrin added to the culture medium interferes with the behaviour of callus tissue. After 5 h of culture, the level of total proteins was higher in treated tissue than in the control, and SDS‐PAGE showed that deltamethrin promoted the increase of some soluble proteins. After 24 h and 14 days of culture, the level of total proteins became similar in both treated and control material. This similarity between control and treated tissues, after 14 days of culture, occurred as a result of the treatment with deltamethrin which caused a decrease of soluble proteins, but an increase in insoluble proteins whereas the opposite was observed for control callus. SDS‐PAGE of both soluble and insoluble proteins showed that only quantitative dissimilarities occurred. This longer treatment also increased the chlorophyll content. Ultrastructural study of the cells revealed that tissue callus cultured for 14 days in the presence of deltamethrin had plastids containing a more developed membranous system, with a higher number of grana and with more compartments than in control cells. Deltamethrin also promoted the abundance of vesicles associated with dictyosomes.This response of the callus tissue to Decis added to the callus medium parallels the behaviour of potato plants treated with this agrochemical under field conditions (Fidalgo, Santos & Salema, 1993).

Oviposition of resistant and susceptible strains of Drosophila melanogaster in the presence of deltamethrin

AbstractOviposition of three strains of Drosophila melanogaster in the presence of deltamethrin was observed. These strains had different levels of physiological susceptibility to deltamethrin. Two‐choice tests were conducted with couples of flies in petri‐dish arenas containing two oviposition dishes. On the first day of the experiment, females were given a choice between a treated oviposition dish and an untreated control dish. On the second day of the experiment, two control oviposition dishes were given to females. Although individual females showed a tendency to aggregate their eggs in one of the dishes, control experiments demonstrated an overall equal distribution of eggs between the dishes. When one of the two oviposition dishes in the arena was treated with deltamethrin, the percentage of females ovipositing and the mean number of eggs laid by females were reduced, compared with control arenas. Females avoided the treated oviposition dish and laid significantly more eggs on the control dish. Furthermore, when the deltamethrin concentration was increased on the first day, female flies postponed their oviposition and laid significantly more eggs on the second day. The resistant strain, SR, demonstrated the same capacity to select the untreated site for oviposition as the susceptible strain, but it showed a smaller oviposition reduction and egg retention. The relationship between physiological and behavioural susceptibility to deltamethrin is discussed.

Stimulation of protein phosphorylation in intact rat brain synaptosomes by a pyrethroid insecticide, deltamethrin

Effects of deltamethrin, a powerful synthetic pyrethroid, on the protein phosphorylation activity in the intact rat brain synaptosome during the time course of depolarization-induced changes were studied. For this purpose, depolarization was induced either by veratridine or high concentration of K +. The level of phosphorylation on various synaptic proteins was found to quickly rise for 15 to 30 sec and return to the resting level in about 3 min. Deltamethrin, when given to the synaptosomes 10 min prior to depolarization, caused stimulation on this depolarization-induced protein phosphorylation activity at > 10 −12 M concentration. To find the cause for such an action of deltamethrin, the effects of ion-channel blockers and calmodulin inhibitors on the same phosphorylation process were studied. The inhibitory effect of a Ca 2+-channel blocker, verapamil, and a Na +-channel blocker, tetrodotoxin (TTX), on the stimulatory action of deltamethrin was first established. However, in neither case were their actions complete. The former reduced the stimulatory effect of deltamethrin on synapsin I but not on calcium- and calmodulin-dependent protein kinase II (CaM-Kinase II), B50, or 38-kDa proteins. The latter could not inhibit the stimulatory action of deltamethrin on synapsin I. Even when both blocking agents were present, the stimulatory action of deltamethrin was apparent. The stimulatory effect of deltamethrin on the phosphorylation rate of phosphoproteins, synapsin I, calcium-calmodulin-dependent protein kinase II and B50 was less when the entire external CaCl 2 was replaced by BaCl 2 in the prelabeling medium. Again, even under these conditions, the stimulatory effect of deltamethrin was evident on all proteins examined. In addition, the effect of calmodulin-inhibitor trifluoroperazine (TFP) was tested in the same manner. This inhibitor was found to reduce the phosphorylation on all of the tested synaptosome-proteins except protein 38 kDa, where there was an increase in phosphorylation in the presence of deltamethrin, especially, at 30, 60, and 180 sec of depolarization. These results indicate that (a) deltamethrin's action is not limited to calmodulin or the sodium or the calcium channel, (b) it must stimulate the release of Ca 2+ from the intracellular storage sites(s), and (c) such a stimulatory action of deltamethrin may be recognized only when the synaptosomes are depolarized regardless of the method of depolarization.

Effect of deltamethrin on antipyrine pharmacokinetics and metabolism in rat

The effect of deltamethrin pretreatment on the pharmacokinetics and metabolism of antipyrine was studied in male rats. The total plasma clearance of antipyrine was significantly decreased by deltamethrin pretreatment (20 mg/kg and 40 mg/kg daily for 6 days prior to antipyrine administration), while the elimination half-life at beta phase, the area under the concentration-time curve and the mean residence time of antipyrine were significantly increased. The magnitude of the observed changes was dose dependent. The urinary excretion of norantipyrine, 4-hydroxyantipyrine and 3-hydroxymethylantipyrine was decreased by 39%, 32% and 26%, respectively (p less than 0.001) in the presence of deltamethrin. In addition, the rate constants for formation of each of these metabolites were significantly decreased by an average of approximately 71%. These results suggest that deltamethrin is capable of inhibiting oxidative metabolism, a finding which could be of clinical and toxicological significance.

Properties of Na channels of identified snail ( Helix pomatia L.) neurones modified by deltamethrin

The effect of deltamethrin was studied on the Na channels of identified snail neurones under voltage-clamp conditions. At 5 × 10 −5 M deltamethrin decreased the resting membrane potential as well as the amplitude of action potentials and increased the negative afterpotentials. The main effect was the slowing down of the inactivation of the Na currents as well as the increase of tail current amplitude. The inactivation curve shifted right along the voltage axis by 10–15 mV. The inactivating phase of Na current could be fitted by two exponentials in the presence of deltamethrin. It was concluded that deltamethrin modified a fraction of sodium channels in the snail neuronal membrane. A kinetic model is proposed for the deltamethrin action in which the presence of two open states, a normal and a modified one, are hypothesized.

Stabilization of sodium channel states by deltamethrin in mouse neuroblastoma cells.

The effect of the pyrethroid insecticide deltamethrin on sodium channels of mouse neuroblastoma cells was investigated using the patch-clamp technique. The study was aimed at determining how the effects of deltamethrin at the whole cell level would be reflected in the modified properties of single sodium channel currents. Whole cell recording showed that deltamethrin prolonged sodium currents in neuroblastoma cells by several orders of magnitude. Single channel recordings showed that a variety of channel states were prolonged by deltamethrin. Not only was the open state prolonged by several orders of magnitude but a closed or inactivated state was also prolonged, leading to less frequent channel openings. A subconducting state and a flickering state were observed in the presence of deltamethrin as well as a state in which channels opened with some delay after the termination of a depolarizing pulse. The results are compatible with the hypothesis that deltamethrin stabilizes a variety of channel states by reducing the transition rates between them. This allows states that are normally very brief to be detected more easily.