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1.
Comparisons with standard susceptible insects showed that a strain of Tribolium castaneum, with a specific resistance to malathion and its carboxylic ester analogues, had no cross-resistance to topical applications of natural pyrethrins. Another strain of T. castaneum, showing resistance to many organophosphorus (OP) insecticides, was cross-resistant to pyrethrins ( × 34) and eight synthetic pyrethroids also applied topically; least cross-resistance occurred with resmethrin ( × 2.2), bioresmethrin ( × 3.3) and phenothrin ( × 4.0). Generally larger resistance factors were recorded with formulations synergised by piperonyl butoxide (PB). The greatest cross-resistance encountered was with unsynergised tetramethrin ( × 338). Apart from tetramethrin, factors of synergism did not exceed 5.7 with either the susceptible or multi-OP resistant strains. PB antagonised six of the nine pyrethroids against the multi-OP resistant strain. Antagonism also occurred with two of these six, permethrin (cis: trans ratio 1:3) and 5-prop-2-ynylfurfuryl ( 1RS)-cis,trans-chrysanthemate (‘Prothrin’), against the susceptible strain. Considering only formulations without the synergist, the most effective compounds against the susceptible strain, relative to pyrethrins, were bioresmethrin (2.7) and permethrin (2.4). Similarly with the multi-OP resistant strain the most effective compounds were bioresmethrin (28), resmethrin (14) and permethrin (6.6). Thus the LD50 (the dose required to kill 50% of the test species) for bioresmethrin against the resistant strain (0.14 μg) only slightly exceeded the LD50 for pyrethrins against the susceptible strain (0.12 μg).  相似文献   

2.
The toxicity of a number of topically applied pyrethroids has been tested against adult male desert locusts, Schistocerca gregaria: the most potent proved to be 5-benzyl-3-furylmethyl (+)-trans-chrysanthemate (bioresmethrin) with a weighted mean LD50 of 4.0 μg/g. The remaining compounds may be ranked in order of toxicity as follows: 5-benzyl-3-furylmethyl (±)-cis-trans-chrysanthemate (resmethrin) > 4-allyl-2,6-dimethyl-benzyl(+)-trans-chrysanthemate > 4-allylbenzyl (+)-trans-chrysanthemate > 2,4,6-trimethylbenzyl (+)-cis-trans-chrysanthemate > 2,3,4-trimethylbenzyl (+)-cis-trans-chrysanthemate > 2,4-dimethylbenzyl (±)-cis-trans-chrysanthemate; 2-methylbenzyl (±)-cis-trans-chrysanthemate. A small factor of synergism (4.2) was obtained with bioresmethrin following pre-treatment with sesamex, but with resmethrin the synergistic ratio (1.6) was of little practical significance.  相似文献   

3.
Abstract

The toxicity of a number of topically applied pyrethroids has been tested in the laboratory against three species of locusts and parathion-resistant and susceptible strains of the Egyptian cotton leafworm. Bioresmethrin, resmethrin and 5-benzyl-3-furylmethyl (+)-cis-chrysanthemate (NRDC 119) proved to be extremely active against one or more of these pests and there were small but noteworthy improvements with the synergists sesamex and TBTP. The field potential of the pyrethroids is discussed against the background of environmental problems associated with some of the insecticides in current use.  相似文献   

4.
A simple laboratory technique for determining the activity of two pyrethroids (5-benzyl-3-furyImethyl DL-cis, trans-chrysanthemate and 5-benzyl-3-furylmethyl D-trans-chrysanthemate) against blackfly larvae (Simulium ornatum) is described. The results showed that the pyrethroids alone or with piperonyl butpxide were of similar activity to Abate (O,O,O',O'-tetramethyl O,O'-thiodi-p-phenylene phosphor-othioate) and Dursban (O,O-diethyl O-3,5,6-trichloro-2-pyridylphosphorothioate), insecticides of known activity against blackfly larvae. However, the pyrethroids cause rapid larval detachment in running water, and may be of value in controlling these insects when used in conjunction with another insecticide.  相似文献   

5.
Comparisons of the susceptibility of several strains of adult Aedes aegypti were made. Mosquitoes from Bangkok and Jakarta were found to be highly resistant to DDT and resistant to pyrethroids relative to a laboratory strain. A strain from Singapore, where less DDT has been used, was susceptible to DDT and pyrethroids. Two strains from the Caribbean had LC50 values to DDT 3 times that of the reference strain while the LC50 values against bioresmethrin synergised with piperonyl butoxide were 1 1/2 times raised. Another two strains from central Africa were 2 times tolerant of DDT and 1 1/2 times tolerant of bioresmethrin plus piperonyl butoxide. Agents which block DDT-dehydrochlorinase, esterases and oxidases each caused small increases in the mortality of the Bangkok strain due to DDT and bioresmethrin as well as augmenting toxicity to the susceptible reference strain. It is tentatively suggested that resistance in the Bangkok strain is due to a combination of the actions of these and perhaps other resistance mechanisms.  相似文献   

6.
One or more weak factors of resistance on autosome 2, and barely detectable resistance on autosome 3, confer moderate resistance to several pyrethroids (5–13-fold) in the field-collected Ipswich strain of houseflies. In these flies, which unlike other pyrethroid-resistant strains lack kdr or super-kdr, pyrethroid resistance probably developed in response to prolonged treatment of buildings for animals with pyrethrins synergised with piperonyl butoxide. Substrains, isolated genetically from Ipswich flies and with resistance only on autosome 2, degraded permethrin more rapidly than susceptible flies and produced larger amounts of very polar metabolites. In this, they differed from flies with kdr or super-kdr which resembled susceptible flies in their metabolism of permethrin. NIA 16388 (propyl prop-2-ynyl phenylphosphonate) was a better synergist and reduced the metabolism of permethrin more than piperonyl butoxide in both the susceptible and resistant insects. The slight increase in synergism and minimal decrease in metabolism when piperonyl butoxide was applied with NIA 16388 indicated that the latter also inhibited detoxication that was sensitive to piperonyl butoxide.  相似文献   

7.
Houseflies (Musca domestica) on Danish farms have developed high multiresistance to organophosphorus compounds, after successive use of several OPs, mainly dimethoate, in recent years. Topical application tests 1971–73 with flies from many farms showed that the high OP-resistance did not involve resistance to pyrethroids (± the synergist piperonyl butoxide (pb)) above a level of 3–7 x, unless field pressure with synergised pyrethrum (py/pb) or other pyrethroids was applied. In 1971–72 moderate to high, often heterogeneous, pyrethroid resistance was found on a few trial farms treated frequently with pyrethroid aerosols (mainly py/pb) and in 1973 on most of 23 trial farms treated intensively with aerosols (or space spray) containing py/pb, bioresmethrin ± pb, tetramethrin/pb or tetramethrin/resmethrin. The effect of field pressure with these different pyrethroids on development of pyrethroid resistance is summarised and discussed. Maximum resistance ratios, R/S at LD50-LD95, were: py/pb (1:5), 40->100; bioresmethrin, 191–770; bioresmethrin/pb (1:5), 55–133; tetramethrin/pb (1:5), 171->200; tetramethrin/resmethrin (1:5), 78->370. The intensity of selection pressure with pyrethroids is believed to be an important factor. Although py/pb has been widely used as a supplementary fly control on Danish non-trial farms, pyrethroid resistance has only been found on a few of them.  相似文献   

8.
Resistance to pyrethroids in insects is rare, but its recent rapid development in the field suggests that this resistance may be facilitated by previous exposure to or by resistance to insecticides of unrelated groups. To test this houseflies of strain 49r2b, originally resistant to dimethoate in the field, were selected eight times during ten generations with either pyrethrum extract or bioresmethrin with or without piperonyl butoxide or with dimethoate. Selecting with any of the pyrethroids led to resistance to these insecticides and in particular to pyrethrum/piperonyl butoxide. Selecting with pyrethrum/piperonyl butoxide resulted in strongest resistance to the pyrethroids tested, whereas selecting with bioresmethrin/piperonyl butoxide resulted in least resistance. These results show that dimethoate-resistant flies selected with pyrethroids can readily develop resistance to these insecticides, but development of resistance can be minimised by using bioresmethrin/piperonyl butoxide. The implications of these findings on the sequential use of insecticides are discussed.  相似文献   

9.
A sample of houseflies initially collected from a pig farm and found to be resistant to bendiocarb, DDT, gamma-HCH, pyrethrins + piperonyl butoxide (PB), tetrachlorvinphos and trichlorfon, was tested for resistance to knockdown by other toxicants. At the KD50 response level, resistance factors were obtained for: permethrin (× 141), deltamethrin (×96), bioresmethrin + PB (×37), resmethrin + PB (×33), fenitrothion (×94), bromophos (×58), iodofenphos (×42), pirimiphos-methyl (×30), dichlorvos (×22), dimethoate (×9), diazinon (×8), methomyl (×4) and methomyl + PB (×4). The slopes of the dose–response lines were lower for the farm strain than for a susceptible strain. This resulted in an increase of resistance factors at the KD95 level by an average of × 1.6. The houseflies on the farm could not be controlled using space sprays of pyrethrins + PB, although resistance to this toxicant was only ×12. However, control was achieved with a methomyl bait.  相似文献   

10.
Strains of Culex quinquefasciatus Say, selected with biopermethrin [(1R)-trans-permethrin] or with (1R)-cis-permethrin, were examined in the larval stage for crossresistance to 30 pyrethroids, DDT, dieldrin, temephos, propoxur, and two organotin compounds. The (1R)-trans-Permethrin-R strain [resistance factor (RF) = 4100-fold] and the (1R)-cis-Permethrin-R strain (RF= 450-fold) of C. quinquefasciutus were cross-resistant to all pyrethroids tested [RF= 12-fold for an allethrin isomer to about 6000-fold for (RS,RS)-fenvalerate] as well as to DDT (RF= about 2000-fold). However, they were not significantly Cross-resistant to dieldrin, temephos, propoxur, and the two organotin compounds. Changes in the alcohol moiety, structural isomerism, and susceptibility of the cyclopropane C-3 side chain to oxidative attack are important factors in determining the level of cross-resistance to various pyrethroids. Limited synergism of the pyrethroids by S,S,S-tributyl phosphorotrithioate and piperonyl butoxide (PB), and of DDT by chlorfenethol and PB, suggested that some non-metabolic mechanism, such as kdr, may be an important component of resistance to pyrethroids as well as to DDT in this mosquito.  相似文献   

11.
Various isomeric mixtures of pyrethroids were examined in topical application tests against houseflies, Musca domestica. On the basis of the activities of the separate isomers of 5-benzyl-3-furylmethyl (±)-cis,trans-chrysanthemate, it was shown that when combined in pairs to give the (±)-trans or (±)-cis or (+)-cis,trans mixtures the observed mortalities did not differ from those expected by simple additive action calculated by the harmonic mean. In contrast the (±)-cis,trans mixture showed considerable antagonism with a mortality only 60% of that expected. Similar evaluations using the separate and combined isomers of bioallethrin [(R,S)-3-allyl-2-methyl-4-oxocyclopent-2-enyl (allethronyl) ( + )-trans-[(1R,3R)-chrysanthemate] and the corresponding (+)-cis-(1R,3S)-chrysanthemate indicate antagonism calculated to be correlated with the content of the (R)-isomer of the alcoholic moiety. Hence the activity of the most active isomer of the “allethrin” series, (S)-3-allyl-2-methyl-4-oxocyclopent-2-enyl ( + )-trans-(1R,3R)-chrysanthemate, (S)-bioallethrin, is not fully realised unless it is present in pure form and a substantial part of the value of bioresmethrin (5-benzyl-3-furylmethyl ( + )-trans-chrysanthemate] as a killing agent is lost when the racemic form is used. In racemic mixtures there is mutual antagonism between pairs of isomers so that considerable masking of activity occurs.  相似文献   

12.
The activity of the (+)-trans-chrysanthemic acid ester of (±)-allethrolone (Bio-allethrin) is shown to be superior to that of the (±)-cis, trans-isomers (allethrin), against houseflies, two species of grain beetle and larvae of the yellow fever mosquito. The efficiency of the (+)-trans-isomer compares favourably with that of pyrethrins when each is used alone or with piperonyl butoxide.  相似文献   

13.
The knockdown and contact killing actions of various pyrethroids were compared using Blattella germanica and Periplaneta americana. A wide range of knockdown activity was found; 5-benzyl-3-furylmethyl (1R)-cis-3-(dihydro-2-oxo-3-thienylidenemethyl)-2,2-dimethylcyclopropanecarboxylate (RU 15525) acted fastest, more rapidly than pyrethrins, against B. germanica as well as having a low LD50 value. Topical application and direct spray tests showed that (S)-α-cyano-3-phenoxybenzyl (1R)-cir-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropanecarboxylate (NRDC 161) was more active as a killing agent, by an order of magnitude, than cismethrin, the next most active compound, and also had considerable knockdown activity. Piperonyl butoxide generally had little synergist effect. Female P. americana were over three times more tolerant than males to a range of insecticides applied topically. Residual knockdown action in the WHO resistance test was observed to provide baseline data. There was little overlap in speed of action between pyrethroids and other insecticides among the compounds tested.  相似文献   

14.
Two substrains of Aedes aegypti, already resistant to DDT and pyrethroids, were further selected using either DDT or permethrin by mass exposure of the females only. DDT selection over 14 generations raised the resistance to DDT so far that no accurate LC50 values could be determined. Selection with permethrin raised the tolerance to an irregular plateau 7–10 times the original. DDT selection in the adults raised the DDT resistance of the larvae, but this could be partly overcome using a dehydrochlorinase inhibitor. The resistance to pyrethroids was increased but tolerance of dieldrin, malathion and propoxur compounds was little changed. Permethrin selection of the adults raised resistance to pyrethroids more than DDT selection but also increased DDT resistance. Similar patterns were found for the larval insects. A strain from Demerara in Guyana showed both DDT and pyrethroid resistance, including strong resistance to pyrethrins together with dieldrin and propoxur. It was concluded that two major independent resistance mechanisms existed in the selected strains, a dehydrochlorinase affecting DDT alone, and an unknown mechanism, probably nerve insensitivity (kdr) affecting both DDT and pyrethroids.  相似文献   

15.
The field strain of Anopheles stephensi, the main malaria vector in south of Iran, was colonized in laboratory and selected with DDT and dieldrin in two separate lines for 3 generations to a level of 19.5- and 14-fold for DDT and dieldrin resistance, respectively. Synergist tests with chlorofenethol (DMC) and piperonyl butoxide (PBO) on the selected strains indicated that dehydrochlorination and oxidative detoxification might be the underlying mechanisms involved in the resistance to dieldrin and DDT in selected strains. DDT selection decreased susceptibility to DDT and pyrethroids including lambdacyhalothrin, permethrin deltamethrin and cyfluthrin. The result also showed that selection with dieldrin caused negative and positive cross-resistance to pyrethroid and fipronil, respectively. Based on these results, it can be concluded that besides metabolic resistance mechanisms, other factors such as mutation in γ aminobutyric acid (GABA) and voltage-gated sodium channels (Kdr) might be involved.  相似文献   

16.
A methomyl sugar bait formulation and permethrin residual spray were compared for the control of a multi-insecticide resistant strain of housefly in a UK pig farm. The methomyl was applied as a granular scatter bait at the manufacturer's recommended rate of 25 mg m?2 active ingredient (a.i.) to the treated floor area. Permethrin was applied at 32, 64 and 128 mg m?2 a.i. to structural surfaces. The highest deposit rate of permethrin used was four times that recommended by the manufacturer for the control of flying insects. The methomyl bait gave effective control but the permethrin spray failed at all deposit rates tested. The use of permethrin increased resistance to this compound at the KD50 level from x 13 to x 560 within 10 weeks and significantly increased the proportion of flies resistant to natural pyrethrins synergised with piperonyl butoxide (P<0.01).  相似文献   

17.
The interactions of natural pyrethrins and nine pyrethroids with the nicotinic acetylcholine (ACh) receptor/channel complex of Torpedo electric organ membranes were studied. None caused significant reduction in [3H]ACh binding to the receptor sites, but all inhibited [3H]perhydrohistrionicotoxin ([3H]H12-HTX) binding to the channel sites in presence of carbamylcholine. Allethrin inhibited [3H]H12-HTX binding noncompetitively, but [3H]imipramine binding competitively, suggesting that allethrin binds to the receptor's channel sites that bind imipramine. The pyrethroids were divided into two types according to their actions: type I, which included pyrethrins, allethrin, bioallethrin, resmethrin, and tetramethrin, was more potent in inhibiting [3H]H12-HTX binding and acted more rapidly (i.e., in <30 sec). Type II, which included permethrin, fluvalinate, cypermethrin and fenvalerate, was less potent and their potency increased slowly with time. Also, inhibition of the initial rate of [3H]H12-HTX binding by type I compounds increased greatly by the presence of the agonist carbamylcholine, but this was not so with type II compounds. The receptor-regulated 45Ca2+ flux into Torpedo microsacs was inhibited by pyrethrins and pyrethroids, suggesting that their action on this receptor function is inhibitory. There was very poor correlation between the potencies of pyrethrins and pyrethroids in inhibiting [3H]H12-HTX binding and their toxicities to house flies, mosquitoes, and the American cockroach. However, the high affinities that several pyrethroids have for this nicotinic ACh receptor suggest that pyrethroids may have a synaptic site of action in addition to their well known effects on the axonal channels.  相似文献   

18.
Enhanced oxidative metabolism appeared to be a major factor involved in resistance to permethrin in a field strain of house flies, selected with permethrin over 4 years. This was shown in the 7.8-fold synergism by piperonyl butoxide which reduced the resistance ratio from 97 to 15. The rate of permethrin detoxication was significantly higher (P=0.05) in the resistant flies compared with a susceptible strain or resistant flies pretreated with piperonyl butoxide. The esterase inhibitor S,S,S-tributyl phosphorotrithioate did not reduce the level of resistance to permethrin in the resistant strain, although some hydrolytic metabolism was apparent. Rates of penetration were similar in susceptible and resistant flies and in resistant flies pre-treated with piperonyl butoxide. A minor unidentified resistance factor, possibly reduced sensitivity of the nervous system, may also have been present in the resistant strain.  相似文献   

19.
The characteristics of a new high-level, field-derived resistance to pyrethroids in Tribolium castaneum (Herbst) were investigated using impregnated-paper and treated-grain assays. Piperonyl butoxide almost completely suppressed the resistance, suggesting that the major resistance mechanism was microsomal oxidation. Resistance extended to all pyrethroids tested and to carbaryl but not to organophosphorus insecticides or to methoprene. Resistance was strongest against α—CN phenoxybenzyl cyclopropanecarboxylate pyrethroids and was correlated with structural modifications of the pyrethroid molecule, results also consistent with oxidative resistance. This resistance will ultimately result in failures to control T. castaneum if pyrethroids, such as deltamethrin, cypermethrin or cyfluthrin, are used in the field, even if they are synergised with piperonyl butoxide. The resistance does not jeopardise organophosphorus materials (e.g. fenitrothion, chlorpyrifos-methyl, pirimiphos-methyl, methacrifos) or methoprene.  相似文献   

20.
Field control failures with pirimiphos-methyl against the rice moth, Corcyra cephalonica (Stainton), in Weslaco, Texas, USA, led us to investigate the susceptibility of this particular strain to pirimiphos-methyl, spinosad, pyrethrins synergized with piperonyl butoxide, and pirimiphos-methyl combined with synergized pyrethrins. In laboratory bioassays, 50 eggs of C cephalonica were exposed to untreated and insecticide-treated corn and sunflower seeds to determine larval survival after 21 days, egg-to-adult emergence after 49 days, and larval damage to seeds at both exposure periods. Pirimiphos-methyl at both 4 and 8 mg kg(-1) did not prevent larval survival or egg-to-adult emergence of C cephalonica on either corn or sunflower seeds, and seed damage was evident at both rates. The C cephalonica strain was highly susceptible to spinosad at 0.5 and 1 mg kg(-1). At both spinosad rates, reduction in larval survival, egg-to-adult emergence, and seed damage relative to the control treatment was > or = 93% on both corn and sunflower seeds. Pirimiphos-methyl and spinosad were generally more effective against C cephalonica on corn than sunflower seeds. The C cephalonica strain was completely controlled on corn treated with 1.5 mg kg(-1) of pyrethrins synergized with 15 mg kg(-1) of piperonyl butoxide. Many larvae survived and became adults on corn treated with synergized pyrethrins at < or = 0.75 mg kg(-1). Corn treated with pirimiphos-methyl at 4, 6 or 8 mg kg(-1) in combination with 0.38 to 1.5 mg kg(-1) of synergized pyrethrins reduced larval survival by > or = 95%, egg-to-adult emergence by > or = 97%, and seed damage by > or = 94%. Our results suggest that the C cephalonica strain can be controlled on corn by combining pirimiphos-methyl with synergized pyrethrins or with synergized pyrethrins at the labeled rate. Although spinosad is not currently labeled for use on stored corn and sunflower seeds, it appears to be effective against C cephalonica on both commodities at very low rates.  相似文献   

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