Behavior of the western pine beetle during host colonization

Area of Science:

• Forestry
• Entomology
• Chemical Ecology

Background:

• Ponderosa pine forests are susceptible to bark beetle infestations.
• Understanding insect behavior is crucial for effective pest management.

Purpose of the Study:

• To investigate the attractant pheromones of the western pine beetle (Dendroctonus brevicomis).
• To determine the optimal conditions and timing for beetle attraction.

Main Methods:

• Living ponderosa pines were baited with female-infested bolts or synthetic pheromones.
• Beetles were captured on sticky screens over 15-46 day periods.
• Tree attractiveness was correlated with beetle density and boring activity.

Main Results:

• Large beetle catches occurred within a narrow 5-10 day window.
• Optimal attraction was observed at tree sections with 3-6 beetles/dm² in galleries approximately 2 cm long.
• Adding males to infested bolts increased catch, supporting frontalin as an attractant.
• Beetle catch correlated with boring activity levels.

Conclusions:

• Male-produced frontalin is a significant attractant for the western pine beetle.
• Beetle response to attractants remains consistent during host colonization.
• Pheromone-based monitoring and control strategies can be optimized by understanding peak activity periods.