[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.

[Interaction with esterases and mechanism of synergistic action of thio- and dithiophosphates containing the fragments of N-acylated glycine and beta-alanine].

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].

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.