# A novel method for quantifying galleries of bark beetles and associates

## TL;DR

A new method using graphite rubbing on rice paper helps quickly map bark beetle larval development under tree bark.

## Contribution

The novel graphite rubbing method enables efficient quantification of bark beetle galleries.

## Key findings

- The graphite rubbing method accurately maps larval galleries on rice paper.
- Transposing the log surface to a 2D plane allows for photography and image analysis.
- The method provides data on gallery area to improve outbreak prediction and management.

## Abstract

Bark beetles (Coleoptera: Curculionidae: Scolytinae) are some of the most destructive forest insect pests in the world. Methods literature is largely limited to trapping, including pheromones and volatiles, and remote sensing. Conversely, little work has been done on methods for quantifying bark beetle development under the bark. Assessing larval development involves marking and measuring each gallery using rulers or mapping tools, which takes much time and effort. We developed a novel graphite rubbing method on rice paper to quickly and accurately map larval bark beetle development under the bark of infested pine logs. We were then able to transpose the log surface onto a 2D plane, allowing photography and image analysis. We also describe alternative methods tested that were not successful. This method allows researchers to quickly collect data on gallery area and, therefore, larval development to have an additional piece of information to better predict and manage future outbreaks.