Various insecticides

and Hammann, I. (1968) Meded. Rijksfac. Landhouwwetensch., Gent, 33, 817. 

Zwierzak, A., Sledzinski, B. and Ciellak, L. (1974) lUPAG, Third Interrtat. Gongr. Pestic. Ghent. Helsinki, Abstr. Book, 411, 414. 

Compounds which do not belong to any of the three types already discussed play a relatively subordinate role among the insecticides. 

Campbell et al. (1934) compared the insecticidal effect of several organic sulfur compounds, and found phenothiazine (1) most effective. It is readily formed by heating diphenylamine (2) and sulfur in the presence of aluminium chloride or iodine. 

It is toxic to several insect pests, but its activity varies within wide limits, which is evidently due to its high sensitivity to oxygen and light. It is oxidised partly to its sulfoxide and partly to chinoidal derivatives (De Edds and Eddy, 1938). 

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Furans occur widely in nature and many are important commercially. Thus alcohol (29) is used in various insecticides. The carbon atoms. joined to the ring oxygen atom are at the carbonyl oxidation level so that (29) can be made by acid-catalysed cyclisation of (30). Analysis... 

The flasks used had narrow mouths, whereas the Laug technique specifies widemouthed beaker flasks. The small opening reduced air exchange and moisture condensed on the insides of the flasks. This condition is not good for flies and probably accounts for the mortality observed in the checks. However, this effect had not shown up 5 hours after the tests were started, and by that time most of the flies in the flasks containing insecticides were down. These tests are qualitative rather than quantitative, but the data indicate that the chemically determined quantities of the various insecticides in the fat extract were nearly equal in toxicity to known samples at the same level. 

Vaughan, J. and E.C. Turner, Jr. 1984. Residual and topical toxicity of various insecticides to the lesser mealworm (coleoptera tenebrionidae). Jour. Econ. Entomol. 77 216-220. 

Table 1 shows the ratios of LD50 values of various insecticidal components for mammals and insects, i.e., indexes for selective toxicity. 

We directed our attention to norchrysanthemic acid esters because they had a lower molecular mass (—14) and showed comparable insecticidal activity with corresponding chrysanthemates. We synthesized various insecticidal norchrysanthemic acid esters and tested their vapor activity against mosquitoes. 

The microwave assisted extraction for organic compounds including polyaromatic hydrocarbons, phenols and organochlorine insecticides, described in section 11.1.8 [25] has been applied to sediments. The application of supercritical fluid extraction to the determination of various insecticides in soils described in section 11.1.7 [23] has been applied to river sediments. 

Larvae of llttoralls treated topically with gossypol (100 y g/g body weight) 24 hours before being treated with various insecticides had a higher LDcq than control insects (272). 

Even prior to Pasteur, alcohol content determination was important as a basis for local, import, and export taxes. Other important applications of accurate wine analysis have been to detect and to accurately determine food additives now there are legal reasons for analyzing wines for sulfur dioxide, organic chloride or bromide, sodium, cyanide, diglucoside pigments, various insecticides, fungicides, etc. Winery control calls for analytical determination of iron, copper, protein, total acidity, pH, tartaric, malic and lactic acids, etc. Finally, quality control... 

One of the earliest examples of such catalysis was demonstrated in 1966 by the Japanese chemist Hitosi Nozaki, who reacted styrene and ethyl diazoacetate in the presence of a chiral Schiffbase-Cu11 complex [72-74], Although the initial enantios-electivity was modest (<10% ee), the principle was proven. Some years later, the companies Sumitomo and Merck used similar copper catalysts for asymmetric cyclopropanation on a multikilogram scale, in the production of various insecticides and antibiotics [75]. One of Nozaki s PhD students at that time was Rioji Noyori, who later developed the BINAP asymmetric hydrogenation catalysts for which he received the 2001 Nobel Prize in Chemistry [7[. 

Studies such as those summarized have helped to provide information on the relative safety or hazard of various insecticides to different components of forest ecosystems. Wise selection and use of insecticides by forest managers taking this type of information into account can allow protection of both forestry and other environmental qualities in areas threatened by attack from forest pests. 

Another common misconception about the fate of chlorinated hydrocarbon insecticides in water is that they remain there forever. Like the soil, aquatic environments are dynamic systems. Residues of chlorinated hydrocarbons dissipate from aquatic environments by codistillation phenomena, metabolism, decomposition, and absorption on surfaces where they are subject to like dissipation forces. Table IV shows the loss of various insecticides by codistillation 20 hours after they were introduced into a jar of water containing mosquito larvae (2). This work was based on still systems. Recent work by investigators at Washington University... 

Cross-resistance is not the same as multiple resistance. Multiple resistance may occur when a population of insects comes into contact with two or more different insecticides. Thus, cross-resistance refers to those cases in which a single defense mechanism confers resistance against various insecticides, whereas multiple resistance refers to cases of resistance to various insecticides conferred by different mechanisms. In general, multiple resistance is due to the sequential selection of populations with replacement insecticides. Each new insecticide selects one or more mechanisms of resistance, and each mechanism usually confers cross-resistance to several other insecticides (Georghiou and Taylor, 1976). Table 10.8 shows the multiple resistance to organophosphate, carbamate, and organochlo-rine insecticides in two strains of Culex pipiens quinquefasciatus. 

Dogs and cats are commonly poisoned by pesticides, herbicides, household products such as antifreeze, and drugs such as acetaminophen applied by humans to their pets. By far the most common toxicities in these small animals involve various insecticides and the overzealous use of these products by owners attempting to control fleas and ticks on their pets. 

CPR. Abbreviation for cyclonene-pyrethrin-ro-tenone. Applied to various insecticide formulations containing as active ingredients approximately 10 parts piperonyl cyclonene, 5 parts rotenone, and 1 part pyrethrin. 

In the next series of experiments the relative sensitivity of the PTX-R in the American cockroach head to various insecticides and... 

In view of the very critical role calcium channels play in a variety of nerve and muscle function, possible effects of various insecticides on calcium channels are too important to be overlooked. It was indeed shown that neurosecretory cells of the stick insect generate action potentials by inward calcium currents (48), and that permethrin increases the electrical activity of these cells at a concentration as low as 5 x 10 " M (49). Although direct demonstration still remains to be seen, it is possible that pyrethroids act on calcium channels to exert their toxic effects (48.50). 

Figure 4. Rates and levels of resistance developed in house flies (Musca) and mosquitoes (Culex) through selection with various insecticides in the laboratory. (Reproduced with permission from Ref. 62.)...

The tolerance values for DDT, i.e. the maximum residue quantities in ppm concentrations for the application of various insecticides, thus also of DDT, have been fixed in the form of statutory decrees or recommendations. 

USE As constituent of various insecticides for larvae of gypsy mnth, boll weevil, etc. 

Ortega P, Hayes WJ, Durham WF. 1957. Pathologic changes in the liver of rats after feeding low levels of various insecticides. AMA Arch Pathol 64 614- 622. 

An emulsifiable concentrate and granules are sold as formulations containing pyriproxyfen. The tape formulation is also sold in Japan under the trade name of Lano . The physicochemical properties of the formulations are very good and storage stability is very good. Moreover, mixtures with various insecticides have also been developed and sold. 

The principal use of chlorine is in the preparation of chlorinated hydrocarbons, such as vinyl chloride, CH2=CHC1 (for polyvinyl chloride plastics), and methyl chloride, CH3CI (for the manufacture of silicones, polymers wilh Si—O bonds and organic groups). Various insecticides are also chlorinated hydrocarbons many of these (such as DDT) are now restricted in their use because of possible environmental damage. 

In this article, the level of susceptibility to various insecticides in different human head louse populations in the US was investigated to assess the distribution of resistance. We also reported on the molecular mechanisms of head louse resistance to pyrethroid mediated by sodium channel mutations. Also discussed were the genotyping techniques for resistance monitoring and the... 

The rank order for these compounds is similar but not identical to those previously reported in the literature. For example, chlorpyrifos-oxon has been reported to be a more potent inhibitor of cholinesterase than paraoxon (18,19) and methomyl has been reported to be a more potent inhibitor than aldicarb (id). A number of factors may account for differences that we observe. The magnitude of difference between paraoxon and chlorpyrifos-oxon IC50 values has been shown to be dependent on both the species and tissue from which the cholinesterase is obtained. In addition, assay factors such as contact time (for the enzyme and inhibitor) as well as the removal of excess inhibitor prior to the addition of substrate are critical factors which differ among reported studies. Nevertheless, taken in context of the screening application we propose for this assay, differences in the rank order for various insecticides between our assay and various reports would likely not be a critical issue. 

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