Pheromone chirality of african palm weevil,Rhynchophorus phoenicis (F.) and palmetto weevil,Rhynchophorus cruentatus (F.) (Coleoptera: Curculionidae)

Abstract

There are four stereoisomers of both 3-methyl-octan-4-ol, the aggregation pheromone of the African palm weevil,Rhynchophorus phoenicis (F.) and 5-methyl-octan-4-ol, the aggregation pheromone of the palmetto weevil,Rhynchophorus cruentatus (F.). Synthetic stereoisomers of 3-methyl-octan-4-ol and 5-methyl-octan-4-ol were baseline-separated on a Cyclodex-B fused silica column. Use of this column in gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometric (GC-MS) analyses revealed that only one stereoisomer, (3S,4S)-3-methyl-octan-4-ol and (4S,5S)-5-methyl-octan-4-ol, is produced by maleR. phoenicis and maleR. cruentatus, respectively, and elicits good antennal responses by conspecific male and female weevils. In field trapping experiments, withR. phoenicis in Côte d'Ivoire andR. cruentatus in Florida, (3S,4S)-3-methyl-octan-4-ol and (4S,5S)-5-methyl-octan-4-ol strongly enhanced attraction of fresh palm tissue, whereas other stereoisomers were behaviorally benign. Stereoisomeric 3-methyl-octan-4-ol and 5-methyl-octan-4-ol may be utilized to monitor and/or manage populations of these two palm weevils.

Mating Behavior and Sexual Response to Aggregation Pheromone of Rhynchophorus cruentatus (Coleoptera: Curculionidae)

“…There is a synergistic effect when these plant volatiles are combined with S,S-5-methyl-4-octanol (cruentol), the aggregation pheromone produced by R. cruentatus males (Weissling et al 1994a;Perez et al 1994). Large aggregations of male and female R. cruentatus are attracted to this combination, presumably for mating and oviposition purposes (Giblin-Davis et al 1994; Weissling et al 1993).…”

Feromônios de agregação em curculionidae (insecta: coleoptera) e sua implicação taxonômica

“…A configuração absoluta desse composto foi determinada como (3S, 4S) (30b). 65,66 Testes de campo revelaram que o isômero (3S, 4S) foi mais ativo, mas que a presença do (3R, 4R) não prejudicou as capturas.…”

Field trapping of Metamasius hemipterus with synthetic aggregation pheromone

“…The inactivity of 5 may simply result from an insufficient release of the natural isomer. Gas chromatography showed that natural 5 was a pure diastereoisomer (Ramirez-Lucas et al, 1996), and probably a pure enantiomer as shown for all the rhynchophorinous pheromones investigated to date (Mori et al, 1993a, b;Oehlschlager et al, 1992;Perez et al, 1994;Phillips et al, 1989, Walgenbach et al, 1987. The presence of the regio-isomer 5-hydroxy-4-propyl-3-heptanone might also interfere with the perception of compound 5.…”