The Forest Health Section currently monitors for two insects using pheromone traps. Pheromones are the chemical signal insects created by the insect for communication. Pheromones are used for numerous types of communication. In some species they are used to call other insects together (e.g. aggregation), in some they are used to repel others (e.g. anti-aggregation), in most insects these chemical signals are very specific and unique. Scientists have been able to identify and reproduce these chemicals in many species, allowing us to monitor species presence/absences and relative abundance in pest management. For both
a) spruce budworm
b) hemlock looper
the sex pheromone is emitted by the female to attract male moths. The Province places traps containing pheromone lures for both throughout the province.
At the end of the season, the number of moths found in the traps give an indication of population trends for that season. These result support additional monitoring efforts such as the SBW fall population forecast. The pheromone traps are useful tools, but they only provide a partial picture on populations because in the case of both spruce budworm and hemlock looper the pheromone attract the male moths only.
Each marker on the spruce budworm map represents three traps hung in a 40m spacing array, the value posted is the average of the three traps counted.