comparing spruce beetle pheromone blends …...comparing spruce beetle pheromone blends between...
TRANSCRIPT
Comparing spruce beetle pheromone blends between eastern and western North America
R. Isitt, D. Huber, K. Bleiker, D. Pureswaran, and K. Hillier
3. Beetles need food before they will produce much pheromone. We drill holes in a spruce bolt and place the beetles just under the bark, stapling fabric over the holes so that the beetles don't leave.
4. After the beetles have fed for 24-48 hours, we take them out and place them into a glass chamber.
5. Pheromone produced by the beetles accumulates in the glass chamber. After 24 hours, we pump the air out of the chamber through a glass tube filled with an adsorbent which the pheromone sticks to. Then we run a solvent through the glass tube, which gives us a liquid sample containing pheromone.
6. To determine the pheromone “recipe”, we place a sample into a machine called a gas chromatograph (GC), which is coupled to another machine called a mass spectrometer (MS). The GC separates chemicals in the sample so that they flow one by one into the MS. The MS generates a chemical fingerprint that lets us identify each chemical and determine the quantity in the sample.
We repeat this process many times to take into account variation among beetles and trees. Then we do the same for spruce beetles in other parts of North America. In this way, we can determine how spruce beetle pheromone differs across North America, which may allow for the production of more effective beetle lures.
For more information, contact Rylee Isitt at [email protected]
The spruce beetle is a North American bark beetle that has the potential to kill large numbers of spruce. By producing a pheromone which can attract many beetles to an infested tree, spruce beetles are able to mass attack and kill trees before the trees can produce enough defensive resin to fight off the attack. But this pheromone can also be used as a tool for keeping spruce beetle populations in check by treating insect traps with pheromone-based lures.
Our goal is to extract pheromones from spruce beetles and determine what differences exist in the pheromone “recipe” between eastern and western North America. Understanding these potential differences will allow lures to be made that are tailored to different geographical regions.
How we extract pheromones from spruce beetles:
1. Find an infested spruce and cut the tree into sections (bolts).
2. Mature beetles will leave bolts to look for a new tree. Before they do, we place bolts into plastic bins so that the beetles can't escape. We collect beetles that have emerged each day.
Support provided by: SERG, CRC program, NSERC, CFI, BCKDF, NSDNR, UNBC, Acadia University, and the KC Irving Environmental Science Centre