CHEMICAL ECOLOGY OF ASTIGMATID MITES XLIX - BETA-ACARIDIAL (2(E)-(4-METHYL-3-PENTENYLIDENE)-BUTANEDIAL), THE ALARM PHEROMONE OF TYROPHAGUS-LONGIOR GERVAIS (ACARINA, ACARIDAE)

Alarm pheromone activity was detected in the hexane extract of Tyropha gus longior. The GLC profile of the extract revealed six components; a lpha-acaridial {2(E)-(4-methyl-3-pentenyl)-butanedial}, tridecane, bet a-acaridial {2(E)-(4-methyl-3-pentenylidene)-butanedial}, an unknown ( M+; m/z 166), n-hexyl linolate and n-hexyl stearate, among which beta- acaridial was the major component, followed by tridecane. These compou nds were each identified by GC/MS spectra and GLC retention times by c omparing with those of authentic compounds. The active eluate from a S iO2 column by 50% ether in hexane consisted of a peak of beta-acaridia l. The compound isolated from the mite was active at 50 ng, and its ac tivity was the same as the authentic beta-acaridial derived from T. pu trescentiae.