3-METHYL-3-BUTEN-1-OL - AN AGGREGATION PHEROMONE OF THE 4-EYED SPRUCE BARK BEETLE, POLYGRAPHUS-RUFIPENNIS (KIRBY) (COLEOPTERA, SCOLYTIDAE)

Porapak Q-captured voltiles of male Polygraphus rufipennis (Kirby) boring in black spruce and white spruce from Newfoundland and British Columbia, respectively, contained 3-methyl-3-buten-1-ol. Volatiles from logs in which the males had been joined by females contained the compound in reduced quantities. Hindgut extracts from male and female P. rufipennis disclosed no male-specific volatiles, but 3-methyl-3-buten-1-ol was detected in extracts of male-produced frass. The compound was not present in extracts from fresh pholoem tissue. P. rufipennis of both sexes responded strongly in the field to traps baited with 3-methyl-3-buten-1-ol released at 4390-mu-g/day. There was little response to unbaited traps, fresh uninfested black spruce logs, or to 3-methyl-3-buten-1-ol released at lower rates. Combination of 3-methyl-3-buten-1-ol with either one of five terpenes prevalent in black spruce did not enhance beetle catch. Approximately half of 20 black spruce trees baited with 3-methyl-3-buten-1-ol were attacked, compared to 20.0% of 10 unbaited control trees. This new aggregation pheromone could be used to monitor or manage P. rufipennis populations.