Objective 1. Testing the response of Ips typographus adults to various combinations of alpha-pinene, limonene and synthetic aggregation pheromone



Testing the response of Ips typographus adults to various combinations of alpha-pinene, limonene and synthetic aggregation pheromone (O1) requires the realization of experiments in the field which will consist of testing the attractiveness l of various combinations of monoterpenes and synthetic pheromone of Ips typographus adult beetles in the conditions when the synthetic pheromone is released with the constant rate and the combination of monoterpenes with variable rate. In this context, there are at least three experiments to be conducted, individually by the release rate of the pheromone dispenser. In each experiment there will be tested at least five different experimental variants, separated by the release rate of the combinations of monoterpenes (alpha-pinene and limonene), the pheromone release rate being constant. Each experiment will be repeated in at least two areas. Each set of variants (which make up an experimental block) will be repeated at least six times in experimental areas. The dispensers with pheromones and monoterpenes will be installed in traps aircraft wing type. The collection of the biological material from the traps will be made at an interval of 3-4 days. At each harvest the dispensers will be moved one step from one trap to another, so that each version goes at least once by each trap position in a block experiment. Making this, it is strongly reduced the influence of the trap position on the response of the Ips typographus beetles.

Achieving this goal requires also laboratory analysis. They consist in the production and testing required dispensers, both the pheromone and those with monoterpenes. After their production, all dispensers will be tested in controlled climate conditions (climate chamber) at constant temperature and humidity (T = 20 ° C, RH = 50%). After testing, the functional dispensers will be kept refrigerated in bags sealed with aluminum foil, until they will be used in the field. After completion of experiments, the recovered dispensers will again be weighed to determine the consumption of the volatile substances. Also, the lab will process the collected biological material. It will be sorted and identified, and for lots of beetles of 50 each, there will be made the identification of sex by dissection and analysis of genital valves. These operations can be done only under the binocular.

Working assumption here is that the answer of the beetles Ips typographus flying will increase in intensity together with the increasing rate of diffusion of monoterpenes to a certain level if the pheromone is released with low rates, beyond which the intensity response will be reduced. When pheromones will be released with high rates, it is expected to reduce the response of the beetles as the rate of release of monoterpenes increases. The expected result is to identify a synergistic effect on response or poare repellent over the response of the Ips typographus adults to synthetic pheromones, of some monoterpene combinations used. Also the proportion of females is expected to decrease as the kairomonal signal intensity increases.