FIELD TRAPPING OF METAMASIUS-HEMIPTERUS WITH SYNTHETIC AGGREGATION PHEROMONE

The five synthetic pheromone components of the West Indian sugarcane b orer (WISB), Metamasius hemipterus (L.) (Coleoptera, Curculionidae) we re tested in the field. The combination of sugarcane (SC) and the majo r pheromone compound, 4-methyl-5-nonanol (1) was attractive. However, the addition of 2-methyl-4-heptanol (2) or 2-methyl-4-octanol (3) was required to reach high catch levels while 5-nonanol (4) or 3-hydroxy-4 -methyl-5-nonanone (5) did not enhance WISB attraction. The redundancy phenomenon, here reported for the first time in rhynchophorinous spec ies, was observed between compounds 2 and 3. SC + 1 + 3 was more attra ctive than living male baits, however, the sex-ratio of the catches wa s equivalent between both treatments. The sex-ratio of catches was aff ected by the qualitative composition of the pheromone formulation. Com pound 3 had a sexual role, attracting more females while 5 seemed to p lay an aggregation role, luring both sexes in the same proportion.