Sex Attractants in Frass Produced by Male Ips confusus in Ponderosa Pine

The attractant response of Ips confusus to frass produced by male beetles boring in ponderosa pine can be reproduced, in a laboratory bioassay, by a combination of compound I with either compound II or compound III, all isolated from frass. The same response by both sexes was elicited by mixtures of synthesized compounds. Compound I is (-)-2-methyl-6-methylene-7-octen-4-ol; compound II, (+)-cis-verbenol; and compound III, (+)-2-methyl-6-methylene-2,7-octadien-4-ol.