Algological factor in pest control and its horizons  <B>Algological factor in pest control and its horizons</B><P>E. B. Gol'din</B><I><P> BREMA Laboratory, R. Luxembourg, Simferopol, Crimea, Ukraine</I><P> Abstract<P> There is a conception of the using hydrobionts and their metabolites in pest control. It's built on the base of analysis of the unfavorable situation existing in the Black sea coastal zone and author's own investigations. The present suggestions consist of a number of links. First of all, it's development and intensification of research of biologically active metabolites of hydrobionts, specifically microalgae, seaweeds, invertebrates, etc. The available facts prove the existence of microalgae, which can be producents of compounds, oppressing the vital functions of herbivorous insects Colorado potato beetle (Leptinotarsa decemlineata), fall webworm (Hyphantria cunea), gypsy moth (Lymantria dispar) and ring silkmoth (Malacosoma neustria). The action of algae can inhibit nutrition, metamorphosis, fat synthesis, growth and reproduction of insects. There are some morphological changes in the larvae, pupae and imago. As a result there is a growth of insects mortality and reduction of their injury. The next step of investigations will be technical elaboration of biological means and preparates, creation of their manufacture and subsequent introduction and application in the integrated systems of plant protection and pest control. This way is more preferable in comparison with the traditional remedies of the pest control, because it's very difficult for pest organisms to be resistant to the nontypical substances. Besides, it will be more economical and profitable. There are vast horizons in the Black Sea coastal region and in the adjoining area for the utilization of their resources of microalgea and the application of this production in the intensive agriculture. The integrated investigations in the field of the utilization of marine inhabitants for the pest control will be mark the beginning of a new system of a plant protection.<P>