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1.
Two insecticides, an insect repellent and an insecticide synergist have been complexed with β-cyclodextrin yielding microcrystalline, wettable, non-hygroscopic formulations. The insecticides fenitrothion and malathion, the repellent diethyltoluamide and the synergist MGR-264 were found to form stable inclusion complexes with β-cyclodextrin. The molecular encapsulation resulted in improved heat and chemical stability, storability, enhanced wettability and dissolution properties of these rather volatile, poorly water-soluble agents. 相似文献
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The major mechanism of resistance to most insecticides in Frankliniella occidentalis (Pergande) is metabolic, piperonyl butoxide (PBO) suppressible, mediated by cytochrome-P450 monooxygenases and conferring cross-resistance among insecticide classes. The efficacy of insecticide mixtures of acrinathrin, methiocarb, formetanate and chlorpyrifos was studied by topical exposure in strains of F. occidentalis selected for resistance to each insecticide. The method consisted in combining increasing concentrations of one insecticide with a constant low rate of the second one as synergist. Acrinathrin activity against F. occidentalis was enhanced by carbamate insecticides, methiocarb being a much better synergist than formetanate. Monooxygenase action on the carbamates would prevent degradation of the pyrethroid, hence providing a level of synergism by competitive substrate inhibition. However, the number of insecticides registered for control of F. occidentalis is very limited, and they are needed for antiresistance strategies such as mosaics and rotations. Therefore, a study was made of the synergist effect of other carbamates not used against thrips, such as carbofuran and carbosulfan, against a susceptible strain and a field strain. Neither carbamate showed synergism to acrinathrin in the susceptible strain, but both did in the field strain, carbosulfan being a better synergist than carbofuran. The data obtained indicate that low rates of carbamates could be used as synergists to restore some pyrethroid susceptibility in F. occidentalis. 相似文献
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Knockdown in insects following application of an insecticide may be defined as the state of intoxication and partial paralysis which usually precedes death. Pyrethroid insecticides cause knockdown within a few minutes in contrast to the slower action of other groups of compounds. Users throughout the world have varying interpretations of knockdown and may apply different emphasis depending upon the species involved and local application techniques. To obtain valid assessments it is necessary to carry out tests under the most realistic conditions possible and to see that the effects of variations in procedure are taken into full account. Some factors which influence knockdown are: single rapid dosing or continuous pick-up during the observation period; size and distribution of spray-droplets; size of test chamber; interaction in mixtures of synergist and insecticides; use of organic solvents or water-based formulations. Examples of these are given. 相似文献
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据资料表明 ,目前大部分的农业、卫生害虫都已对一种或多种农药产生不同程度的抗性 ,而且几乎涉及所有类型农药 [1 ] 。如何通过科学用药来抑制或延缓抗性种群的抗性发展 ,成为我们今后抗性治理的重点和难点。针对敏感和抗性初始频率较低的种群所采用的轮用、混用以及使用增效剂等用药策略对有一定抗性水平的抗性种群是否仍然奏效 ?针对这一问题 ,作者以对溴氰菊酯已产生中等抗性 ( R/ S=2 8.2 4)和高等抗性 ( R/ S=5 4.1 2 )的家蝇为试虫 ,采用轮用 (换用辛硫磷 )、混用 (辛硫磷与溴氰菊酯的混剂 )、使用增效剂(溴氰菊酯与增效磷混剂 )三… 相似文献
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The screening of 30 substituted 1-hydroxyimidazoles as herbicides, anthelmintics, insecticides, bacteriostats, fungicides, coccidiostats and nematocides disclosed a broad spectrum of biological activity in all but two compounds. The most pesticidally active imidazoles carried an interdiazal benzenoid or heterocyclic aromatic ring substituent with a phenolic or potentially phenolic group attached thereto. 相似文献
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Ernst-Heinrich Pommer 《Pest management science》1984,15(3):285-295
By the N-substitution of morpholine with alkyl or cycloalkyl groups containing 12 to 13 carbon atoms, compounds were obtained with good fungicidal activity, in particular, against powdery mildew in barley. An increase in activity was achieved when the carbon atoms in the heterocyclic ring bore one or two methyl groups, the 2,6-combination being preferred. In the case of sterically different substances, no difference in activity was observed between the cis- and trans-forms. Substituted arylalkyl amines, in which the aromatic ring and the alkylene chain were substituted appropriately, showed very good activity against powdery mildew in wheat and barley, as well as against cereal rust fungi. Steric conditions also play an important role with this type of molecule, as has been proved by detailed investigations on isomers with different configurations in the morpholine moiety, in the alkylene intermediate chain, and in the carbocycle. 相似文献
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López-Soler N Cervera A Quinto V Abellán J Bielza P Martínez-Pardo R Garcerá MD 《Pest management science》2011,67(12):1549-1556
BACKGROUND: Western flower thrips (WFT), Frankliniella occidentalis (Pergande), is among the most important crop pests in the south‐eastern region of Spain. Its increasing resistance to insecticides constitutes a serious problem, and understanding the mechanisms involved is therefore of great interest. Use of synergists to inhibit the enzymes involved in insecticide detoxification is widely used to determine their responsibility for insecticide resistance. However, they do not always act as intended or expected, and caution must be exercised when interpreting synergist results. RESULTS: Laboratory‐selected strains of WFT were used to analyse the effects of the synergists piperonyl butoxide (PBO), S,S,S‐tributyl phosphorotrithioate (DEF) and methiocarb on total esterase activity. Significant differences were found, indicating esterase activity inhibition by DEF, a lower effect for methiocarb and a small inhibition of the activity by PBO. Esterase isoenzyme inhibition by these compounds showed a similar result; this assay revealed an extreme sensitivity of Triplet A (resistance‐associated esterases) to DEF. In an in vivo assay carried out with these compounds at different incubation times, only DEF caused posterior in vitro esterase activity inhibition, with a maximum effect 1 h after treatment. CONCLUSION: In this work, only DEF shows true synergistic inhibition of WFT esterases. Copyright © 2011 Society of Chemical Industry 相似文献
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BACKGROUND: Phthalic acid diamide derivatives are among the most important classes of synthetic insecticides. In this study, a 3,3‐dichloro‐2‐propenyloxy group, the essential active group of pyridalyl derivatives, was incorporated into phthalic acid diamide derivatives with the aim of combining the active groups to generate more potent insecticides. RESULTS: Thirty‐one new phthalic acid diamides were obtained, and these were characterised by 1H and 13C NMR. The structure of N2‐[1,1‐dimethyl‐2‐(methoxy)ethyl]‐3‐iodo‐N1‐[4‐(3,3‐dichloro‐2‐propenyloxy)‐3‐(trifluoromethyl)phenyl]‐1,2‐benzenedicarboxamide was determined by X‐ray diffraction crystallography. The insecticidal activities of the compounds against Plutella xylostella were evaluated. The title compounds exhibited excellent larvicidal activities against P. xylostella. Structure‐activity relationships revealed that varying the combination of aliphatic amide and aromatic amide moieties, or the nature and position of substituent Y on the aniline ring, could aid the design of structures with superior performance. CONCLUSION: A series of novel phthalic acid diamides containing a 3,3‐dichloro‐2‐propenyloxy group at the 4‐position of the aniline ring were designed and synthesised. Structure‐activity relationships with the parent structure provided information that could direct further investigation on structure modification. Copyright © 2012 Society of Chemical Industry 相似文献
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Scott McN. Sieburth Charles N. Langevine David M. Dardaris 《Pest management science》1990,28(3):309-319
Silicon effectively substitutes for quaternary carbon in etofenpr ox-type insecticides; the resulting dimethyl-4-ethoxyphenyl-3-(4-fluoro-3-phenoxyphenyl)propylsilane is a broad-spectrum insecticide with extremely low toxicity to fish. Four regions of this new silane insecticide have been systematically altered. The methyl groups on silicon appear to be critical for activity. Replacement of the fluorine with hydrogen results in a substantial loss of activity. The aromatic rings of the phenoxyphenyl fragment are best tethered by oxygen or carbonyl, the methylene and nitrogen analogs being of very low toxicity to the test species. The activity ranking of the methylene and carbonyl tethers is opposite to that found for ester pyrethroids. The relationship of insecticidal activity to the aromatic substituent para to the silicon atom has been found to correlate with the molar refractivity of the substituent. Replacement of a tetra-substituted carbon atom with a silicon atom can simplify construction of test compounds and thus be advantageously used in the exploration of structure—activity relationships. A novel method for preparing allylbenzenes from aromatic aldehydes was also developed. 相似文献
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Barry T. Brown Oddvar Johansen Gerard F. Katekar Wolfgang H. F. Sasse 《Pest management science》1973,4(4):473-484
A series of compounds related to 1-(2′-carboxyphenyl)-3-phenylpropane-1,3-dione has been synthesised and their effects on root geotropism assessed using cress and ryegrass seedlings. The more active members have been found to be highly potent, abolishing root geotropism at concentrations as low as 0.01 mg/litre. In this respect they compare favourably with TIBA and NPA. It is suggested that a 2-carboxy-phenyl radical separated by a 3 carbon unit from a second aromatic ring is essential for activity, and that a C-1 oxygen function enhances the effect. 相似文献
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John E Casida 《Pest management science》2010,66(11):1163-1170
The crowning achievement for Michael Elliott came in 1973 when his most outstanding candidate insecticide from 25 years of research crystallized from hexane solution. The stereochemically pure crystalline compound was the most potent synthetic insecticide ever made until that time, and it was highly selective for insects compared with mammals. It was given the name deltamethrin. Sequential stereospecific crystallization to isolate the most potent epimer and base‐catalyzed racemization of the remaining less active isomer could be used to produce deltamethrin efficiently on a large scale; it became the billion dollar crystals. Elliott's discoveries at Rothamsted in England with Norman Janes and David Pulman of resmethrin, permethrin, cypermethrin and ultimately deltamethrin provided crop protection and malaria control for millions of people. Michael also laid the background for lipophilic amide, dithiane and other insecticides and nerve probes that are not involved in pyrethroid cross‐resistance. Some aspects of these investigations were best conducted at Berkeley, where Michael studied pyrethrins in 1969, synthetic pyrethroids in 1974 and alternative insecticides in 1986–1988. This review considers Michael's seminal discoveries in insecticide chemistry, with emphasis on his Berkeley years. Copyright © 2010 Society of Chemical Industry 相似文献
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Paolo Piccardi Pietro Massardo Franco Bettarini Angelo Longoni 《Pest management science》1980,11(4):423-431
In the search for new juvenile hormone analogues (JHAs), a general approach was chosen based on the substitution of the isoprene unit, that carries the epoxy function in the natural hormone JHIII, by 3,3,3-trichloropropyl, 2,2-dichlorocyclopropyl- methyl, 3,3-dichloroallyl, or 3-chloroprop-2-ynyl groups. Accordingly, several terpenoid aromatic JHAs were prepared with, or without, oxygen atoms in the aliphatic chain. Structure-biological activity relationships of the most active compounds toward the yellow mealworm (Tenebrio molitor) and the large cabbage white butterfly (Pieris brassicae) are given. With a view to preparing synthetically accessible analogues, some alkyl phenyl ethers were also made, which were not branched in the aliphatic chain and were related terminally to the most active compounds. They were only moderately active against insects when tested for morphogenetic activity, but exhibited a good field persistence. The occurrence of a moderate acaricidal activity among these analogues prompted the examination of several 1,4-disubstituted-phenyl derivatives. The ovicidal effectiveness of these products against a susceptible strain of the two-spotted spider mite, Tetranychus urticae, was ten or 100 times higher than that of the well known and highly potent JHAs. 相似文献
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Victor SR Crisóstomo FR Bueno FC Pagnocca FC Fernandes JB Correa AG Bueno OC Hebling MJ Bacci Júnior M Vieira PC da Silva MF 《Pest management science》2001,57(7):603-608
The development of Leucoagaricus gongylophorus, the fungus cultured by the leaf-cutting ant Atta sexdens was inhibited in vitro by synthetic compounds containing the piperonyl group. In addition, worker ants that were fed daily on an artificial diet to which these compounds were added had a higher mortality rate than the controls. The inhibition of the fungal growth increased with the size of the carbon side chain ranging from C1 through C8 and decreasing thereafter. 1-(3,4-Methylenedioxybenzyloxy)octane (compound 5) was the most active compound and inhibited the fungal development by 80% at a concentration of 15 micrograms ml-1. With worker ants the toxic effects started with compound 5 and increased with the number of carbons in the side chain. Thus, for the same concentration (100 micrograms ml-1) the mortality rates observed after 8 days of diet ingestion were 82%, 66% and 42%, for 1-(3,4-methylenedioxybenzyloxy)decane, 1-(3,4-methylenedioxybenzyloxy)dodecane and compound 5, respectively, whereas with commercial piperonyl butoxide the mortality was 68%. The latter compound, which is known as a synergist insecticide, was as inhibitory to the symbiotic fungus as the synthetic compound 5. The possibility of controlling these insects in the future using compounds that can target simultaneously both organisms is discussed. 相似文献
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Action of pyrazoline-type insecticides at neuronal target sites 总被引：1，自引：0，他引：1
Kristopher S. Silver 《Pesticide biochemistry and physiology》2005,81(2):136-143
Pyrazoline-type insecticides were discovered in the early 1970s, but did not readily yield commercial insecticide products due to their unfavorable toxicity profiles and environmental properties. The recent registration of indoxacarb, a compound derived from pyrazolines, has drawn renewed attention to this insecticide class. This review summarizes the development of the pyrazoline-type insecticides and examines the mechanism of action of these compounds based on available electrophysiological, pharmacological, and toxicological information. 相似文献
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BACKGROUND: The housefly, Musca domestica L., and stable fly, Stomoxys calcitrans (L.) are cosmopolitan pests of both farm and home environments. Houseflies have been shown to be resistant to a variety of insecticides, and new chemistries are slow to emerge on the market. Toxicities of selected semiochemicals with molecular structures indicative of insecticidal activity were determined against adults from an insecticide‐susceptible laboratory strain of houseflies. The three most active semiochemicals were also evaluated against recently colonized housefly and stable fly strains. RESULTS: Nineteen semiochemicals classified as aliphatic alcohols, terpenoids, ketones and carboxylic esters showed toxicity to houseflies and stable flies. Rosalva (LC50 = 25.98 µg cm?2) followed by geranyl acetone and citronellol (LC50 = 49.97 and 50.02 µg cm?2) were identified as the most toxic compounds to houseflies. Permethrin was up to 144‐fold more toxic than rosalva on the susceptible strain. However, it was only 35‐fold more toxic to the insecticide‐tolerant field strain. The compounds generated high toxicity to stable flies, with LC50 values ranging from 16.30 to 40.41 µg cm?2. CONCLUSION: Quantification of LC50 values of rosalva, citronellol and geranyl acetone against susceptible housefly and field‐collected housefly and stable fly strains showed that semiochemicals could serve as potent insecticides for fly control programs. Copyright © 2010 Society of Chemical Industry 相似文献
18.
G. Unterstenhöfer 《European journal of plant pathology / European Foundation for Plant Pathology》1969,75(1):21-30
The principles are discussed of the development of synthetic insecticides. Development of new insecticides is based on the following facts: (1). The successful combination of all properties constituting a good insecticide into one chemical substance is a matter of chance. (2). Species and strains of insects usually react specifically. The usual sequence of five steps in the development of an insecticide is briefly described. Trends in insecticide research are determined by biological, ecological and economic aspects as well as by the results of basic research. 相似文献
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Ying-Qian Liu Chun-Yan ZhaoLiu Yang Yong-Long ZhaoTing-Ting Liu 《Pesticide biochemistry and physiology》2011,99(1):39-44
Twenty podophyllotoxin analogues were first tested for their insecticidal activity against the fifth-instar larvae of Brontispa longissima in vivo. Among them, compounds 6-9 and 19 showed more promising and pronounced insecticidal activity than toosendanin, a commercial insecticide derived from Melia azedarach. The different insecticidal activity ranges of compounds 1-20 indicated that variation of chemical structures in the podophyllotoxin skeleton markedly affected the activity profiles of this compound class, and some important SAR information has been revealed from it. The results obtained from SAR analysis show good correlation with the docking models as well as with QSAR studies, which allows for the rational design of more potent podophyllotoxin derivatives in the development of potential new insecticides. 相似文献