[Hygienic assessment of larvicides against mosquitoes, the carriers of transmissible infections].

To substantiate safety requirements in the use of effective larvicidal rotation schemes, the authors have attempted to make an environmental-and-hygienic assessment of the active ingredients of a number of larvicides. A comparative procedure is proposed for the hygienic assessment of risky/safe use of larvicides, which is based on the calculations of respective hygienic parameters for reservoir water and soil and on those of ecological parameters in combating insects that are carriers of transmissible infections.

[Leptinotarsa decemlineata Say sensitivity to ionizing radiation and pesticides].

The effects of acute gamma-irradiation on the Colorado potato beetle (Leptinotarsa decemlineata Say) and sensitivity of insects, long time exposed on radioactively contaminated territories, to pesticides were studied. LD50 values of insects to ionizing radiation during the ontogenesis process was shown to increase (from 8 to 48 Gy). Differences were noted in the development rates of the natural population of beetles collected on agricultural lands with 137Cs contamination density of 0.05-1.2 MBq/m2, with the sensitivity to various pesticide groups being the same.

[Interaction with esterases and mechanism of synergistic action of thio- and dithiophosphates containing the fragments of N-acylated glycine and beta-alanine]. / Vzaimodeistvie s ésterazami i mekhanizm sinergisticheskoi aktivnosti tio- i ditifosfatov, soderzhashchikh fragmenty N-atsilirovannykh glitsina i beta-alanina.

We studied the interaction between O,O-diethyl-S-[(N-acyl-N-alkoxycarbonylalkyl)aminomethyl]thiophosphates and mammalian cholinesterases as well as esterases from insect tissue extracts by kinetic methods and disc electrophoresis. The coefficients of combined effect of these compounds or their dithioanalogs with permethrin were determined. The obtained data suggest that the synergistic effect on the common cockroaches and houseflies is chiefly due to carboxylesterase inhibition by monothioderivatives and monooxygenase suppression by dithioderivatives, respectively.

[Specific interaction between esterases and 2-butylthio-2-thio-1,3,2-oxazaphosphorynane and its cyclic and acyclic analogs]. / Osobennosti vzaimodeistviia s ésterazami 2-butiltio-2-tio-1,3,2-oxsazafosforinana i nekotorykh ego tsiklicheskikh i atsiklicheskikh analogov.

We studied the anticholinesterase and anticarboxylesterase effects of 1,3,2-oxazaphosphorynane derivatives and certain cyclic and acyclic analogs on the two enzymes of homoiotherms (ACE from human erythrocytes and BuCE from horse serum) as well as the enzymes from insect tissues (the nerve cord of the American cock-roach and the cephalic region of the domestic fly). The differences in in vitro antiesterase activity of cyclic thionic and the corresponding oxo derivatives of phosphorinane were revealed. The mechanism of the esterase active center phosphorylation not only splitting off the outgoing group (in vivo) but also opening the cycle by P-O bond (in vitro and possibly in vivo) is usually proposed to explain the higher inhibiting activity of the thionic compounds compared to the oxonic ones. The possible involvement of this phosphorylation mechanism in the synergistic activity of the studied compounds is discussed.

[Mechanism of action of 2-aryloxy-2-thio-1,3,2-oxazaphosphorinane pesticides]. / Issledovanie mekhanizma deistviia pestitsidov riada 2-ariloksi-2-tio-1,3,2-oksazafosforinana.

The interaction of 2-aryloxy-2-thio-1,3,2-oxazaphosphorinanes exhibiting nematocide, insecticide/acaricide, and synergetic activities with monoamine oxidases and the interaction of the corresponding oxones, 2-aryloxy-2-oxo-1,3,2-oxazaphosphorinanes, with various cholinesterases, carboxyl esterases, and monoamine oxidases were studied. We showed that the thioderivatives inhibited monoamine oxidases, whereas oxones, which are, as a rule, weak cholinesterase inhibitors, strongly inhibited carboxyl esterases of the American cockroach and were transformed with monoamine oxidases into the strong cholinesterase inhibitors, acyclic phosphamidates. This allowed us to explain the low toxicity of the thioderivatives, the high toxicity of the oxoderivatives, and the great difference in toxicities of thio- and oxocompounds in the 1,3,2-oxazaphosphorinane series. The capacity of thioderivatives to inhibit monoamine oxidases and of oxoderivatives and their further activation products to inhibit carboxyl esterases, i.e., both enzymes responsible for pyrethroid detoxication in insects, explains the synergetic activity of the 1,3,2-oxazaphosphorinane series.

[A method of using synergists in studying the level of activity of enzyme systems and their participation in the mechanism of action of insecticides on insects]. / K metodike ispol'zovaniia sinergistov pri izuchenii urovnia aktivnosti nekotorykh fermentnykh sistem i ikh uchastiia v mekhanizme deistviia insektitsidov na nasekomykh.

An indirect toxicology method was used to assess the monooxygenase (MO) and nonspecific esterase (NE) activities in three synanthropic cockroach species and four races of houseflies with the help of common and novel organophosphorus and pyrethroid synergists: piperonyl butoxide (PB), S,S,S-tributyltrithiophosphate (TBTP), Kitazin-P, Karesan, butylmercapto-2-thio-1,3,2-oxazaphosphorinan (AO-6), and 2-phenylmercapto-2-thio-1,3,2-oxazaphosphorinan (AO-2). The relationship between the coefficient of synergistic effect (CSE) and the concentrations of MO and NE inhibitors was described, and the minimum effective concentrations with the highest synergistic effect were determined. These concentrations are advisable for use in the insect enzyme assays and studies of insecticide detoxification and insect resistance to them.

[Disinfection and insect control of passenger bedding by radiation exposure]. / Dezinfektsiia i dezinsektsiia radiatsionnymi sposobom postel'nykh prinadlezhnostei passazhirskikh vagonov.

Radiation exposure using gamma sources with Co-60 was employed for the disinfection and disinfection of bedding from passenger cars. An effective scheme of exposure was developed and optimal dose determined: 10 kGy.

[The interaction of phoscarban with the esterases of houseflies and synanthropic cockroaches]. / Vzaimodeistvie foskarbana s ésterazami komnatnykh mukh i sinantropnykh tarakanov.

Interactions of phoscarban and its "oxon" with the esterase complex of the house-fly imago and four species of synanthropic cockroaches were studied. Phoscarban and its oxon have a wide spectrum of effects on the esterase complex in cockroaches and flies. These compounds are not specific inhibitors of any of the zones of esterase activity. Their insecticide effect depends on their ability to inhibit both choline esterases, which are responsible for nervous activity, and carboxyl esterases, which are involved in the detoxication of these compounds. We studied the species specificity of the esterase complex, including individual types and fractions, to phoscarban and its oxon in the order Dictyoptera. It was especially distinct for membrane-bound and water-soluble forms of choline esterases.

[The enzyme systems in natural populations of the housefly Musca domestica highly resistant to organophosphate insecticides]. / Izuchenie nekotorykh fermentnykh sistem u prirodnykh populiatsii komnatnykh mukh Musca domestica, vysokorezistentnykh k fosfororganicheskim insektitsidam.

Two natural population of house flies from the Podol'sk District, Moscow Province have been studied. The both natural populations proved to be highly resistant to organophosphorus insecticides and sensitive to pyrethroids. The activity of esterases and glutathione-S-transferase has been studied, as well as the sensitivity of the enzymes of esterase complex in vitro to TBTP, DDVP and paraoxon, as compared with that of the sensitive strain SRS. Reliable differences have been established in the sensitivity of non-specific esterases to organophosphorus compounds. The esterase spectrum of enzymes from heads and abdomens of house flies has been studied by electrophoresis in PAAG and the zones of esterase activity have been revealed in the presence of two substrates: 2-HA and ATX. Differences in the activity of catecholamine esterase and cholinesterase and inn the sensitivity of cholinesterase from the natural populations to organophosphorus compounds have been established.

[The level of insecticide resistance in natural populations of houseflies]. / Uroven' rezistentnosti k insektitsidam prirodnykh populiatsii komnatnykh mukh.

The resistance to chlorophos and some pyrethroids (permethrin, fenvalerate and ethofenprox) were determined in house fly imagos from Moscow, some towns of the Moscow Province (Dmitrov, Kolomna, Zagorsk and others). Tajikistan, Turkmenia and also Czechoslovakia. The tested populations from the USSR were highly resistant to chlorophos (more than 100 times) and susceptible or tolerant to pyrethroids. Czechoslovak populations were more resistant to pyrethroids.

[Insecticidal activity of pyrethroids for houseflies and German cockroaches]. / Insektitsidnaia aktivnost' piretroidov dlia komnatnykh mukh i ryzhikh tarakanov.

Insecticidal and knock-down effects of eight pyrethroids, belonging to 2 types as to their chemical structure and specific action towards the nervous system, on the domestic flies' and German cockroaches' imago were assessed comparatively. Pyrethroids of the 2nd type, especially deltametrine, proved to be more effective against domestic flies as well as German cockroaches. Activity of the pyrethroids of the 1st type featured rapid knock-down effect and was practically independent from varying concentrations. The knock-down was reversible even at high concentrations. In case of the 2nd type of pyrethroids, the knock-down effect was concentration-dependent. Domestic flies, on the whole, were more sensitive to the effect of pyrethroids of the 1st type. The use of pyrethroids of the 2nd type against nonflying sinathropic insects would be advisable because they produce a higher insecticidal effect as well as irreversible knock-down.