IDENTIFICATION OF (-ACORADIENE AS AN AGGREGATION PHEROMONE FOR GNATOCERUS-CORNUTUS (F) (COLEOPTERA, TENEBRIONIDAE)())

The broad-horned flour beetle, Gnatocerus cornutus (F.), was investiga ted for an aggregation pheromone. The male volatile collected with a P orapak Q column showed attractancy for both sexes, indicating male bee tles produced aggregation pheromone(s), Purification of the volatile f rom 761,000 male-day-equivalents (MDE) by silica gel column chromatogr aphy yielded two different active fractions. The major pheromone (tota l of 12.3 mg; 1MDE = 16.2 ng) isolated with a 5% AgNO3-SiO2 column was identified as a (+)-acoradiene on the basis of NMR, MS, IR and optica l rotation. This acoradiene was active at more than 0.16 ng per disk, showing attractancy at the same level as the crude male volatile. An u nidentified minor pheromone was ten times less active than the major p heromone. (C) 1998 Elsevier Science Ltd. All rights reserved.