Abstract
Hexane extracts derived from an unidentified Oulenzia sp. showed the alarm pheromone activity. The extract was composed of the following 10 compounds; tridecane, neral, pentadecane, dodecane, 3-hydroxybenzene-1,2-dicarbaldehyde, geranial, (Z)-7-pentadecene and 7-hydroxyphthalide in decreasing order together with two unknown compounds. After fractionation with a silica gel column, the active fraction consisted of a mixture of neral and geranial. Neral was found to show the activity, but geranial was not. Neral was, therefore, identified as the alarm pheromone of this species.
