When love is a trap
Bug of the Month
Pulse growers will know about pea leaf weevils and the challenges they can cause a crop. Recently, the weevils arrived on the Canadian Prairies and scientists want to monitor the spread of the pest.
Word Alert: Semiochemical
- a pheromone or other chemical that conveys a signal from one organism to another to modify the behavior of the recipient organism
The larvae feed on pulse root nodules affecting the plant uptake of nitrogen. The larvae live underground making them harder to monitor, so scientists studying the weevils use above ground traps baited with male-produced aggregation pheromone and volatiles released by host plants.
They tried 12 different types of traps and the pheromone-baited pitfall traps caught the most weevils. They used various concentrations of semiochemical lures in spring and fall and caught both males and females in the traps. Traps with only plant volatiles didn’t work indicating that if you want to trap weevils, you must use attraction pheromones! For pea leaf weevils, when love is in the air – beware!