Difference in effect of pheromone for monitoring the European spruce bark beetle

In recent decades there have been an increasing number of outbreaks of the
European spruce bark beetle (Ips typographus) in Europe. A large amount of
sanitary felling has taken place, with significant economic and ecological
consequences. In order to anticipate such large-scale outbreaks, an
effective monitoring system should be set up. One important aspect of
monitoring is the decision on which pheromone to use. We suggest a
framework for selecting an effective pheromone with few side effects and
implemented it on five different pheromones under different disturbance
conditions: Pheroprax, IT Ecolure, Ipstyp, Ipsowit and Typosan. We set 50
traps in two areas with sites that were disturbed and undisturbed by wind
storms. We collected bark beetles from traps every one to two weeks from
the end of March until the end of September in 2019. We investigated the
number of bark beetles caught, bark beetle dynamics, amount of bycatch and
predators, the taxonomic groups of the bycatch and the overall costs of
the monitoring system. We found that Pheroprax, IT Ecolure and Ipsowit
caught the most bark beetles and best showed the population dynamics.
There was a low amount of bycatch (less than 6% of the total catch) and
predators (a few individuals), but some groups seem to prefer certain
pheromones. The cost of the pheromones increased with their effectiveness.
However, pheromone costs are low relative to the personnel costs involved
in setting traps and collecting bark beetles. The framework and the
results will help professionals to decide which pheromones to purchase for
their bark beetle monitoring system.