STUDY OF SYNTHETIC PHEROMONES FOR MONITORING OF THE GOLDEN TWIN-SPOT MOTH <i>CHRYSODEIXIS CHALCITES</i>
The study of synthetic pheromones for monitoring of the golden twin-spot moth Chrysodeixis chalcites was conducted within the framework of the State task (R&D registration number: AAAAA 20-12071490011-8). Golden twin-spot moth is a regulated quarantine pest of the territory of the Russian Federation (Unified list of quarantine organisms of the Eurasian Economic Union from 30.11.2016). It causes damages to several economically important crops, especially, in greenhouses (tomato, pepper, etc.). This paper presents the results of a sex pheromone synthesis and its field trial for monitoring of the golden twin-spot moth Chrysodeixis chalcites . The developed method provides the use of monoene alcohol acetates as key stages of the alkylation reaction with α-bromo-Ω-chloralkanes of the corresponding lithium derivatives in liquid ammonia. The efficacy evaluation of synthetic pheromones on the attraction and capture of the golden twin-spot moth males was also studied. Introduction. One of the main tasks of the National Plant Protection Organizations is to establish the phytosanitary status of the country's territory. Phytosanitary monitoring of the Russian Federation territory for Chrysodeixis chalcites has never been carried out. The development of the golden twin-spot moth synthetic pheromone for such monitoring receives priority. Object of the study is a synthetic pheromone of the golden twin-spot moth Chrysodeixis chalcites . Materials and methods. The development of synthesis and the production of the synthetic pheromone samples of the golden twin-spot moth were carried out in the Laboratory of pheromones synthesis and application of the All-Russian Plant Quarantine Center. A gray rubber septum lures from brombutyl were impregnated with different synthetic pheromone mixtures. Five variants of the mixtures were tested in five replications. Mixture variants were tested with Rhomb type traps made of thick laminated cardboard. Traps with all pheromone mixture variants were fixed at a height of 1.5-2.0 m at the beginning of the pest flight. Traps were placed on a randomized way at a minimum distance from each other - 30-50 m. The traps were monitored weekly. Results and conclusions. During the first stage of the research work in 2020, a new method of the pheromone component synthesis was developed for the golden twin-spot moth Chrysodeixis chalcites . New synthesis schemes provide the use of monoene alcohol acetates as key stages of the alkylation reaction with α-bromo-Ω-chloralkanes of the corresponding lithium derivatives in liquid ammonia, which reduces the number of synthesis stages and avoids the need for chromatographic purification of the obtained intermediates. Thus, two components of the golden twin-spot moth pheromone: Z7-dodecene-1-ol acetate (Z7-12Ac) and Z9-tetradecene-1-ol acetate (Z9-14Ac) were synthesized. The developed synthesis of Z11-hexadecene-1-ol acetate (Z11-16Ac) by alkylation of 10-bromodecane-1-ol tetrahydropyrane ether with a lithium derivative of 1-hexine in liquid ammonia allowed achieving a high 99% stereoisomeric purity of the product. The developed method of Z-9-dodecene-1-ol acetate (Z9-12Ac), in which the alkylation of the lithium derivative of tetrahydropyranyl ether 9-decine-1-ol with brom-ethane in liquid ammonia was used as a key stage, made it possible to avoid working with dangerous butine-1 gas. During the field trials, the attractiveness of four variants of the synthetic pheromone mixtures was confirmed. Based on the results of the first stage of the work, it can be assumed that the presence of acetates with Z7- and Z9- dibonds (Z7-12Ac, Z9-12Ac, and Z9-14Ac) is necessary to be in the synthetic pheromone mixture composition to attract the target type. Z11-hexadecene-1-ola acetate (Z11-16Ac) possibly could be an attraction inhibitor. The exact role of the components will be specified in further work.