Physiological and biochemical indicators in Norway spruces freshly infested by Ips typographus: potential for early detection methods

Intoduction The bark beetle Ips typographus currently represents the primary pest of Norway spruce ( Picea abies ) in Central Europe. Early detection and timely salvage cutting beetle-infested trees are functional management strategies for controlling outbreaks. However, alternative methods being developed, possible indicators infestation can be assessed through changes physiological, biochemical, beetle-acceptance characteristics trees. Method This study monitored infested non-infested before 3 weeks after natural attack. Permanently installed sensors recorded physiological features, such as sap flow, tree stem increment, surface temperature, soil water potential, to monitor availability. Defensive metabolism characteristics, host acceptance, attractiveness were discretely several times per season. forest stand that was later attacked by beetles had lower availability during 2018–2020 seasons compared non-attacked stands. Results After attack, flow increment significantly than intact ones, temperature moderately increased, even when measured inner from shadowed side. Infested respond attacks with a surge monoterpene emissions. In addition, freshly more accepted males no-choice bioassays, higher number caught passive traps first week infestation. Conclusion most promising early include only certain meteorological conditions, elevated emissions, high catches traps.