Reducing pest risk in birch wood products - The effective heat treatment for bronze birch borer Agrilus anxius (Coleoptera: Buprestidae) prepupae

PURPOSE:
Determine the time and temperature combinations that result in partial and complete mortality of larvae of the Bronze birch borer

DESCRIPTION:
The protection of forest resources and the safe trade of forest products require phytosanitary measures which reduce the risk of pest movement to novel environments. Technically sound science to develop measures are required to support safe trade policies. Heat treatment is a widely available, efficient and effective method to produce phytosanitary wood products destined for trade. Defining the optimal heat treatment dose needed to kill insects in wood products reduces the risk of spreading exotic species to new environments with the lowest possible energy cost which in turn reduces environmental impacts and provides confidence in current guidelines for heat treatment regulations. The minimum effective heat treatment dose (time and temperature) for Agrilus anxius (bronze birch borer) prepupae was determined using the Humble water bath applying heat in vitro. Heat treatment was assessed using a controlled increase in temperature to simulate the heat ramp applied to wood in industrial kilns and conventional heat chamber operations. Target temperatures between 51 and 56 °C for exposure durations of 15 and 30 min were tested to determine the minimum effective dose. Prepupal A. anxius did not survive exposure to 53, 54, 55 or 56 °C for 30 min or 54 and 56 °C for 15 min. Chronic mortality was observed at 53 °C for 15 min treatments. Evaluating the effect of specific heat treatment parameters for other forest pests is recommended to identify and validate the minimum temperature and time required to kill wood pests in order to avoid introducing exotic species with wood products and limit pest movement.

Data was collected at the following sites:
Insects for these experiments were collected from trees harvested in Victoria, British Columbia and the Valcartier Research Forestry Research Station, Valcartier, Quebec. Experiments were conducted at the Pacific Forestry Centre in Victoria, British Columbia and the Laurentian Forestry Centre in Ste Foy, Quebec. 

PARAMETERS COLLECTED:
If larvae survived 24 hours post-treatment
If larvae survived 8 weeks post treatment
Number of days elapsed between treatment and the larvae entering the pupal stage
Number of days elapsed between treatment and the larvae entering the adult stage
Number of days the larvae stayed alive
Weight of larvae, in grams, at the start of the experiment

NOTES ON QUALITY CONTROL:
Original data entry by Tyranna Souque and Esme John. Data checked and validated prior to analysis by Meghan Noseworthy, Tyranna Souque, Esme John, and Chris MacQuarrie. Data further checked and validated prior to publication by Meghan Noseworthy, Tyranna Souque, Esme John, and Chris MacQuarrie.

PHYSICAL SAMPLE DETAILS:
No physical samples retained.

SAMPLING METHODS:
-Removing bronze birch borer from trees using chainsaws, drawknives and forceps
-measuring bronze birch borer with a scale (weight)
-observing health of bronze birch borer (alive/dead) using a microscope

USE LIMITATION:
To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.


Organization: Natural Resources Canada | Ressources naturelles Canada