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1.
Solutions of tetramethrin, RU 11679, or cismethrin caused uncoupled convulsions in 30–40 min in exposed thoracic ganglia from SNAIDM house flies at concentrations down to 10?10M: whereas these same compounds at 10?6M concentrations failed to produce poisoning symptoms when perfused onto the exposed ganglia of the kdr strain of house fly. The pyrethroid analogs examined had a negative temperature coefficient of action on the exposed thoracic ganglia from SNAIDM flies. DDT and GH-74 possessed positive temperature coefficients of action on the exposed thoracic ganglion of susceptible house flies. It is concluded that the central nervous system of the kdr strain of house fly is resistant to pyrethroid action; furthermore, the resistance appears to be widespread throughout the house fly nervous system, involving sensory, motor, and central neural elements.  相似文献   

2.
Specific binding of [35S]t-butylbicyclophosphorothionate ([35S]TBPS) to a house fly thorax-plus-abdomen membrane preparation at 20°C is characterized by apparent Kd and Bmax values of 0.21 μM and 2.5 pmol/mg protein, respectively, an association half-time of 13 min at 2 nM, and a biphasic dissociation curve showing half-times of 15 and 35 min. Specific binding is reduced at 37°C apparently due to instability of the receptor-ligand complex and at 0°C as the result of very slow association. [35S]TBPS binding is diminished by detergents, stimulated by GABA at low ligand concentration, and inhibited by picrotoxinin and certain barbiturates, benzodiazepines, bicyclophosphorus compounds, and polychlorocycloalkane insecticides. The potency of TBPS and three related phosphorothionates in displacing [35S]TBPS parallels their toxicity on injection into house flies; the corresponding bicyclophosphates are less active in both assays. Cyclodienes of low toxicity are generally poor inhibitors of radioligand binding. α-Endosulfan and syn-12-hydroxyendrin are more potent than their β and anti isomers, respectively, both as inhibitors of TBPS binding and as toxicants. Analysis of Scatchard plots indicates that picrotoxinin and heptachlor epoxide are non-competitive inhibitors of [35S]TBPS binding. The [35S]TBPS binding site of the house fly membrane preparation differs from that extensively studied in mammalian brain with respect to their responses to many insecticides and GABAergic agents.  相似文献   

3.
Of six juvenile hormone analogs of the alkyl 3,7,11-trimethyl-2,4-dodecadienate type, only the isopropyl ester was strongly morphogenic in the house fly, Musca domestica L. In vitro assays revealed that house fly microsomes contain B-esterases as well as oxidases which metabolize such analogs. However, these esterases did not hydrolyze the isopropyl ester, ZR-515. Enzymes prepared from larvae, pupae, and adults were all active and there was evidence that in the late larval stage the esterase activity was cyclic, showing a minimum in the early third instar and a maximum a few hours later. When microsomes from two susceptible and two resistant house fly strains were compared for metabolic activity against the juvenile hormone analogs, those from the resistant strains were 1.3 to 20 × higher in oxidase activity but there was no difference in esterase activity. The oxidative metabolism of two analogs ZR-515 and 512 was greatly enhanced when the flies were induced with phenobarbital but there was no enhancement in metabolism of three of the remaining analogs and only a slight enhancement of a fourth. It is concluded that the insecticidal action of ZR-515 is largely due to its stability in the presence of the house fly esterases.  相似文献   

4.
House fly (Musca domestica L.) microsomes prepared from larvae, pupae, or adults contain three enzyme system which can metabolize juvenile hormone I: an esterase, an oxidase, and epoxide hydrase. The presence of the oxidase is indicated by the increased metabolism when microsomes are supplemented with NADPH and by the occurrence of additional metabolites tentatively identified as products arising from oxidation of the 6, 7 double bond. Additional evidence of the activity of the oxidase system is the increased metabolism of juvenile hormone I by the NADPH-dependent system from phenobarbital-induced insects, by inhibition of the oxidation by piperonyl butoxide and carbon monoxide, and by the greater metabolism of the hormone by microsomes from insecticide-resistant (high oxidase) strains. In vivo studies of house fly adults treated with 3H-labeled juvenile hormone I reveal a pattern of metabolism similar to that seen during NADPH-supplemented in vitro metabolism. The three enzymes have somewhat different patterns of activity during the larval stage of the house fly, juvenile hormone esterase and epoxide hydrase beginning at a high level of activity in the young larvae while the juvenile hormone oxidase is low at this stage. In the late larval stage all three enzymes show increased activity followed by declines during the pupal stage and further increases in the adult stage. Comparison of in vitro enzyme levels of the house fly, flesh fly (Sarcophaga bullata Parker), and blow fly [Phormia regina (Meigen)] showed that, although the enzymes were present in the latter two species, their activity on a per insect basis was considerably less than that of the house fly.  相似文献   

5.
Hexadeuterio-lindane(γ-BHC-d6) was several times as toxic as lindane against the mosquito (Culex pipiens pallens), house fly (Musca domestica), German cockroach (Blattella germanica) and American cockroach (Periplaneta americana). The neuroexcitatory activity of these two compounds did not differ. Lindane was considerably synergized by piperonyl butoxide, but lindane-d6 was not. A large isotope effect was observed in the in vivo breakdown of lindane-d6. Thus, the intrinsic toxicities of both compounds are equivalent. The difference in insecticidal activity seems to be due to the different rates of detoxifying biodegradation caused by the kinetic deuterium isotope effect.  相似文献   

6.
In vitro inhibition of house cricket head, house fly head, and bovine erythrocyte acetylcholinesterase by O,O-dimethyl S-aryl phosphorothioates was studied by Main's kinetic treatment. The potency of the compounds as reflected by the bimolecular reaction constants (ki) indicated that house fly head acetylcholinesterase was the most sensitive to the inhibition followed by house cricket head and bovine erythrocyte acetylcholinesterase. There are no linear relationships between the phosphorylation rate constants and the total binding energies for the inhibition of three enzymes by this series of compounds, suggesting that the initial binding and the phosphorylation rate are not related. The structure and activity relationships were analyzed by multiple regression analyses with the use of Hammett's sigma, alkaline hydrolysis rates of the compounds, and pi constants. The hydrophobic bonding of the compound on the enzyme surface as reflected by the pi constant played a significant role in the determination of the potency of the inhibition of house cricket head and house fly head acetylcholinesterase by those compounds. However, the alkaline hydrolysis rates of the compounds, or the Hammett's sigma values seems to play a more important role in the determination of the inhibition of bovine erythrocyte acetylcholinesterase. Moderate insecticidal activity toward house crickets, house flies, and mosquito larvae were found.  相似文献   

7.
Methamidophos (O,S-dimethylphosphoramidothioate, Monitor) is an organophosphorus, cholinesterase-inhibiting insecticide. The rate constant (ki) for inhibiting rat plasma cholinesterase (ChE) was 1.57 ± 0.03 × 103M?1 min?1, for rat erythrocyte ChE was 8.86 ± 1.10 × 103M?1 min?1, and for rat brain ChE was 6.58 ± 0.42 M?1 min?1. Brain and plasma cholinesterases spontaneously recovered from over 90% inhibition at 30 min to 50% inhibition in 4 and 14 hr, respectively. Pralidoxime increased the rate of reactivation in vitro. In vivo, rats poisoned with methamidophos exhibited signs of cholinergic stimulation. The LD50 of ip methamidophos in male rats was 15 ± 0.7 mg/kg. Pralidoxime (60 mg/kg) and atropine (10 mg/kg) given with the methamidophos increased the LD50 to 52 ± 4.9 mg/kg and 60 ± 0.4 mg/kg, respectively. In rats given 12.5 mg methamidophos (an LD20), ChE activity was depressed 95 ± 12.5% in plasma, 92 ± 0.6% in stomach, and 88 ± 1% in brain at 1 hr after injection. At 48 hr after injection ChE activity had returned to 60% or more of control values in each of the tissues. Administration of a single dose of 60 mg/kg of pralidoxime along with methamidophos did not increase ChE activities at the times and places it was measured.  相似文献   

8.
The kinetics of accumulation and elimination of lethal doses of [14C]carbofuran in the hemolymph of the house fly suggest a one-compartment open model. Carbofuran in the hemolymph appeared to be in equilibrium with that in the tissues very soon after treatment.Following topical application of carbofuran, the rate of onset of symptoms of poisoning was correlated with the amount of carbofuran in the hemolymph, and the onset of convulsions only occurred after the concentration of carbofuran in the hemolymph reached μM levels. This value correlated well with neurobioassays of known concentrations of carbofuran perfused in saline onto the isolated thoracic ganglion.Following topical doses, carbofuran concentration in the hemolymph reached a peak within an hour and then gradually declined. At an LD60 dose, the initial decline in carbofuran concentration in the hemolymph over time was significantly slower than the decline after an LD10 dose, suggesting saturation kinetics.Hemolymph was collected from house flies for up to 3 hr following topical application of toxic amounts of carbofuran. Thereafter, hemolymph volume decreased and blood samples could not be collected. Curiously, hemolymph samples could be collected for 5 hr from house flies that were injected with toxic doses of carbofuran.  相似文献   

9.
The toxicity of spinosad, a new insecticide derived from the bacterium Saccharopolyspora spinosa, was evaluated against susceptible and resistant strains of house fly (Musca domestica L.). Spinosad was highly toxic to house flies based on 72-h LD50 values and the symptoms of poisoning were consistent with a neurotoxic mechanism of action. Spinosad was relatively slow acting, with the maximum toxicity noted at 72 h. Piperonyl butoxide and S,S,S,-tribu-tylphosphorotrithioate synergized the toxicity of spinosad by 3·0- and 1·8-fold, respectively, while diethyl maleate had no significant effect. These results suggest that there is a small degree of monooxygenase-mediated spinosad detoxification in house flies, while hydrolases may be only minimally important and glutathione transferases may have no role. There were no substantial levels of cross-resistance detected, except in the LPR strain where a low 4·3-fold cross-resistance was observed. The cyclodiene-resistant OCR strain was 2·7-fold more sensitive to spinosad than the susceptible strain (CS). These results suggest that cross-resistance may not be a limiting factor for the use of spinosad against house flies. © 1998 Society of Chemical Industry  相似文献   

10.
The insecticidal properties of 1-(7-ethoxygeranyl)-2-methylbenzimidazole (EGMB) were investigated on larval and adult house flies. Unsynergised EGMB gave topical LD50 values of 0.53 μg per female fly on NAIDM strain house flies. When flies were pretreated with 5.2 μg piperonyl butoxide, susceptibility was increased (LD50 0.12 μg per female fly). House fly larvae were less susceptible to EGMB (LD50 2.2 μg). Poisoning with EGMB resulted in a rapid reduction in locomotor activity of both larval and adult house flies. This reduction in locomotion was progressive and led to complete paralysis. Various parameters of larval nervous system function were investigated in larvae during these early phases of poisoning. As early as 15 min after dosing larvae with LD95 doses of EGMB, sensory nerves were less responsive. Over a somewhat longer time (2–4 h), neurally evoked contractures were adversely affected by EGMB. In some cases, this effect appeared to be due to reduced postsynaptic potential amplitude; in other instances, it appeared to be due to an effect independent of neuromuscular transmission. The close temporal correlation between behavioural and electrophysiological observations suggests that the nervous and muscular systems are important sites of action of EGMB.  相似文献   

11.
The development, fecundity and survival ofStethorus gilvifrons Mulsant (Coleoptera: Coccinellidae) fed onTetranychus cinnabarinus Boisduval (Acari: Tetranychidae) were recorded at three constant temperatures (20, 25 and 30±1°C) and 50±10% relative humidity, under two photoperiods (16:8 L:D and 8:16 L:D) produced using artificial light (4000 lux). The development rate for the egg stage (r[Te]) increased linearly with increasing temperature (r[Te]=0.0132*T ? 0.0955; R2=0.95). The theoretical egg-development threshold was estimated to be 7.24°C; 75.75 degree-days (DD) were required for hatching. The total development time (r[Tt]) also decreased linearly with increasing temperature (r[Tt]=0.0039*T ? 0.0325; R2=0.98). The development threshold was estimated to be 8.33°C and full development from egg to adult required 256.41 DD. Higher temperatures resulted in a shorter generation time (T 0) and decreased net reproductive rate (R 0). The length of the previposition and postoviposition period, as well as longevity, decreased significantly with increasing temperature under both photoperiods. The oviposition and postoviposition periods, longevity, and total fecundity were not significantly affected by photoperiod. The values of both the intrinsic rate of increase (r m ) andR 0 were highest under the long-day photoperiod at 25°C. The mortality rate was lowest at 20°C under the short-day photoperiod. Of the conditions tested, the optimum temperature for rearingS. gilvifrons was 25°C and the optimum photoperiod was 16:8 L:D.  相似文献   

12.
Wysoki  M.  Izhar  Y. 《Phytoparasitica》1981,9(1):19-25

Apanteles cerialis Nixon, a thelytokous braconid parasitoid ofBoarmia (Ascotis) selenaria Schiff., attacks young caterpillars (preferably 2–5 days old) of this pest in avocado plantations of Israel. At 27±1°C, oviposition rate is 2.04 progeny per day and 18.3 progeny over the entire life span. The development time of preimaginal stages is 16.1 and 15.2 days at 25° and 30°C, respectively, and increases to 37.3 days at 17°C. The pupal stage averages 4.4 days at 30°C and 13.5 days at 17°C. The average longevity of adults is 24.2 and 7.9 days at 30° and 17°C, respectively. In avocado orchardsA. cerialis appeared in considerable numbers in late summer and autumn; it was slightly hyperparasitized by the ichneumonid waspStictopisthus sp. (1 and 2% of the samples at one site).

  相似文献   

13.
The metabolism of a selectively toxic derivative of carbofuran, 2,2-dimethyl-2,3-dihydrobenzofuranyl-7 N-dimethoxyphosphinothioyl N-methylcarbamate (PSC), was examined in the house fly, rat, and mouse. In house flies, PSC is metabolized mainly to carbofuran and related oxidation products containing the intact N-methylcarbamyl ester moiety. Degradation to phenolic products was the principal route of metabolism in rodents. The results indicate that the selective toxicity of PSC between insects and mammals is attributable to differing pathways of metabolism.  相似文献   

14.
The penetration and metabolism of 2 - isopropoxyphenyl N-methyl-N-(2-methyl-4-tert - butylphenylsulfenyl)carbamate or sulfenyl-propoxur was examined in the house fly and honeybee. Reduced penetration was found to be a factor contributing to the lower toxicity of sulfenyl-propoxur to the honeybee. Honeybees and house flies metabolized sulfenyl-propoxur qualitatively in a similar manner. Quantitatively, larger amounts of propoxur were found in the house fly than in the honeybee soon after treatment with sulfenyl-propoxur. The slower rate of conversion of sulfenyl-propoxur to propoxur was considered as another factor responsible for the lower toxicity of the sulfenylated derivative to bees. The high susceptibility of bees to propoxur was related to high internal amounts of unchanged propoxur found soon after treatment.  相似文献   

15.
Insecticides have been extensively used for house fly control in China, with dichlorvos and deltamethrin being widely used. Knowledge about the current status of insecticide resistance and the underlying genetic changes is crucial for developing effective fly control strategies. The susceptibility to dichlorvos and deltamethrin, and the frequencies of genetic mutations involved in insecticide resistance were studied in five field populations of the house fly collected across China. Bioassay results show that flies exhibit 14- to 28-fold resistance to dichlorvos and 41- to 94-fold resistance to deltamethrin, indicating that dichlorvos and deltamethrin resistance are common in house fly populations in China. Molecular analysis reveals that flies from the five various locations carry resistance alleles at multiple loci and have diverse allelic types, different relative frequencies and combinations of each allele. Four non-synonymous single nucleotide polymorphisms (SNPs) (i.e. V260L, G342A/V, F407Y) in acetylcholinesterase (Ace) and two mutations (W251L/S) in a carboxylesterase (MdαE7) were commonly present in the field house flies. The L1014H rather than L1014F mutation in the voltage sensitive sodium channel gene (Vssc) was widely distributed in Chinese house flies. CYP6D1v1, which confers pyrethroid resistance, was found in all the five tested populations in China, although its frequency in house fly from Shandong province was very low. Our results suggest that resistance monitoring and management of house flies should be customized for a given location.  相似文献   

16.
The metabolism of O,S-dimethyl propionyl- and hexanoylphosphoramidothioate was investigated in the white mouse and house flies. Compared to the hexanoylphosphoramidothioate, the propionyl analog is approximately 35-fold more toxic to house flies and is 10-fold less toxic to mice. On a percentage basis, substantially larger amounts of methamidophos were detected in house flies treated topically with the propionylphosphoramidothioate than in flies treated with the hexanoyl derivative. The reverse was evident in the case of the mouse where much larger amounts of methamidophos were formed after oral treatment with the hexanoylphosphoramidothioate. Minor amounts of other metabolic products also were detected, including an unknown from the hexanoylphosphoramidothioate. Metabolism of the S-methyl moiety to carbon dioxide appeared to be a major pathway for metabolic degradation of both compounds in both the white mouse and house fly. The difference in toxicity of the two acylphosphoramidothioates to the mouse and house fly is attributed to difference in the amounts of methamidophos formed in the animals.  相似文献   

17.
Dinitroaniline herbicides such as oryzalin (3,5-dinitro-N4,N4-dipropylsulfanilamide) disrupt mitosis in the meristematic cells of seedling plants by inhibiting the formation of microtubules. For further understanding of the biochemical mechanism of action of oryzalin, laboratory analyses with isolated plant tubulin must be employed. Plant tubulin from flagella of the alga Chlamydomonas was isolated and purified. This tubulin was incubated with [14C]oryzalin, and free oryzalin was separated from oryzalin bound to plant tubulin by miniature DEAE-cellulose chromatography. Scatchard analysis predicts a molar ratio of oryzalin bound to plant tubulin of 1.0 ± 0.1 when oryzalin is incubated with plant tubulin for 30 min at pH 6.9 and 25°C. The association constant for the oryzalin-tubulin complex is 2.08 ± 0.08 × 105M?1 at 25°C. The thermodynamic values for the formation of the oryzalin-tubulin complex at 25°C are ΔGo = ?7.25 ± 0.02 kcal mol?1, ΔHo = 6.5 ± 0.2 kcal mol?1, and ΔSo = 46 ± 2 cal mol?1 deg?1 (mean ± standard error). Oryzalin has little or no affinity for intact microtubules, previously denatured plant tubulin, actin, bovine serum albumin, calmodulin, ferredoxin, trypsin, or urease, indicating oryzalin is specific for the biologically active conformation of plant tubulin. Oryzalin binds to plant tubulin to form a complex that may be incapable of polymerizing into microtubules.  相似文献   

18.
Diazinon toxicity to a susceptible strain of house fly (Musca domestica L.) was synergized by tridiphane [2-(3,5-dichlorophenyl)-2-(2,2,2-trichloroethyl)oxirane], a herbicide synergist. Both diazinon and tridiphane were partially metabolized in the house fly by glutathione (GSH) conjugation. Synergism appeared to be due to inhibition of diazinon metabolism/detoxification. Crude glutathione S-transferase (GST) preparations from the house fly catalyzed GSH conjugation of diazinon, tridiphane, 3,4-dichloronitrobenzene (DCNB), and chloro-2,4-dinitrobenzene (CDNB). Tridiphane and the GSH conjugate of tridiphane appeared to inhibit diazinon GSH conjugation, but diazinon did not inhibit tridiphane GSH conjugation. The enzymatic rate of tridiphane GSH conjugation was 22 times the rate of diazinon GSH conjugation; therefore, attempts to assay tridiphane as an inhibitor of diazinon GSH conjugation were inconclusive because of the high concentration of tridiphane GSH conjugate produced during the assay. CDNB underwent enzymatic GSH conjugation at a rate 240 times faster than that of tridiphane and 5000 times faster than that of diazinon. GSH conjugation of CDNB was not inhibited by tridiphane, but was inhibited by the GSH conjugate of tridiphane. In vivo, the GSH conjugate of tridiphane was produced in sufficient concentration to cause the observed inhibition of diazinon metabolism and synergism of diazinon toxicity. However, the possibility that parent tridiphane caused or contributed to the inhibition of diazinon metabolism and synergism of diazinon toxicity could not be excluded. Inhibition of diazinon metabolism did not appear to be due to depletion of either GSH or GST.  相似文献   

19.
Knockdown and lethal activities of meta- and para-substituted benzyl (1R)-trans-chrysanthemates against the house fly were measured under synergistic conditions using piperonyl butoxide as an inhibitor of oxidative metabolism and NIA 16388 as an inhibitor of hydrolytic degradation. The variations in these activities were quantitatively analyzed in terms of physicochemical substituent effects using electronic, hydrophobic, and steric parameters of the aromatic substituents, and regression analysis. The most significant parameter in determining these activities is the steric bulkiness represented by the van der Waals voluem, the effect of which is highly specific to substituent positions. The substituent effects on knockdown and lethal activities against the house fly are shown to correspond well, respectively, with those on the convulsive and lethal activities against the American cockroach. The relationship between these symptomatic activities against the house fly and the neurophysiological activities determined by using excised nerve cords from American cockroaches were also quantitatively analyzed. Each house fly symptomatic activity was found to be analyzable by a linear combination of the neuroexcitatory and neuroblocking activity indices when the transport factor was separated by using the hydrophobicity parameter.  相似文献   

20.

BACKGROUND

Ethanedinitrile (EDN) is a fumigant being commercialized worldwide as an alternative phytosanitary treatment to methyl bromide (MB) for forest products. The penetration characteristics of MB and EDN were measured through the bark of wooden blocks (100 × 100 × 50 mm) cut from the upper (average bark thickness 5 ± 2 mm) and lower (average bark thickness 25 ± 5 mm) trunk of recently felled pine (Pinus radiata D.Don) trees. Doses of 48 g m−3 MB and 50 g m−3 EDN were applied to chambers at 10 and 20°C for 10 h.

RESULTS

Penetration of MB was influenced by the interaction between fumigation time and temperature, with concentrations increasing at a higher rate at 20°C compared with at 10°C. After 10 h, an average concentration of 8.05 ± 0.89 g m−3 had penetrated the bark of log sections at 20°C, whereas 5.20 ± 0.89 g m−3 was measured at 10°C. By contrast, the factors examined in this study did not significantly impact the penetration of EDN. Concentration × time (CT) values for MB under the bark were 35.20 ± 2.30 g h m−3 at 10°C and 55.85 ± 9.58 g h m−3 at 20°C; whereas for EDN, CT values were 19.50 ± 6.80 g h m−3 at 10°C and 19.08 ± 4.10 g h m−3 at 20°C.

CONCLUSION

MB can achieve a higher concentration under the bark of log sections during simulated fumigations, but all of the factors examined affected the ability of MB to penetrate the bark of wooden blocks. By comparison, the penetration of EDN through the bark is more consistent than MB under laboratory conditions. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.  相似文献   

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