Dynamics of internal isoprenoid metabolites in young Picea abies (Norway spruce) shoots during drought stress conditions in springtime.

Currently, large areas of Picea abies (Norway spruce) stands in Europe are increasingly affected by drought and heat waves. Moreover, early spring drought has occurred with much higher frequency. Our work focuses on physiological changes induced by drought in four-year-old spruce seedlings during shoot elongation.

Anti-attractant activity of (+)-trans-4-thujanol for Eurasian spruce bark beetle Ips typographus: Novel potency for females.

Background: Eurasian spruce bark beetles (Ips typographus) use both attractant and anti-attractant semiochemicals to find suitable mature host trees. Trans-4-thujanol is abundant in young, unsuitable spruce trees. Electrophysiological studies have demonstrated its high activity levels, but field data are lacking.

The 2018 European heatwave led to stem dehydration but not to consistent growth reductions in forests.

Heatwaves exert disproportionately strong and sometimes irreversible impacts on forest ecosystems. These impacts remain poorly understood at the tree and species level and across large spatial scales. Here, we investigate the effects of the record-breaking 2018 European heatwave on tree growth and tree water status using a collection of high-temporal resolution dendrometer data from 21 species across 53 sites.

Peripheral modulation of pheromone response by inhibitory host compound in a beetle.

We identified several compounds, by gas chromatographic-electroantennographic detection (GC-EAD), that were antennally active in the bark beetle Ips typographus and also abundant in beetle-attacked spruce trees. One of them, 1,8-cineole (Ci), strongly inhibited the attraction to pheromone in the field. Single-sensillum recordings (SSRs) previously showed olfactory receptor neurons (ORNs) on I.

Feeding response to host and nonhost compounds by males and females of the spruce bark beetle Ips typographus in a tunneling microassay.

Research on host selection by bark and wood boring insects has concentrated on flight orientation behavior. Less is known of the factors that govern the steps successive to host landing. Here, we discuss chemical factors involved in host acceptance by bark beetles and a new microassay.