Reproductive activity and diapause induction in Ips typographus

Numerous insects evolved diapause to cope with seasonally re-occurring adverse conditions, affecting multiple life-history traits, including reproduction, survival, and voltinism. The spruce bark beetle Ips typographus – a major disturbance agent in spruce-dominated forests of Eurasia – enters reproductive diapause to survive harsh winters. Induction of facultative diapause is mainly regulated by short daylengths, but modified by warm temperatures, potentially postponing entry into diapause. Knowledge on the interplay of these cues under natural conditions is still lacking despite its importance for phenology and management in a changing climate. We conducted a comprehensive field study over three years along an elevational gradient in South-West Germany to quantify diapause expression in I. typographus under a broad range of natural photoperiod and temperature conditions. Most individuals entered diapause in mid-August (daylengths < 14 hours), regardless of tempe..., , , # Reproductive activity and diapause induction in Ips typographus

[https://doi.org/10.5061/dryad.p8cz8wb0f](https://doi.org/10.5061/dryad.p8cz8wb0f)

## Description of the data and file structure

In a multi-year field study along an elevation gradient, we recorded the reproduction of *Ips typographus* in experimental logs in order to assess its diapause induction. To this end, logs were successively exposed to incoming beetles for one week to subsequently debark them and record multiple factors, to infer diapause induction.

### Files and variables

#### File: data.csv

**Description:** Data recorded using experimental logs. \"NA\" refers to values that are not available.

##### Variables

* log_id: Unique ID of the respective log
* site_name: Site at which the sample was taken
* year: Year in which the sample was taken
* calendar_week: Calender week in which the sample was taken
* surface area: surface area of the experimental log in square centimeters
* adults_alive: number of living ...