Sex pheromone of the scarab beetle

The female-produced sex pheromone of the scarab beetle, Phyllophaga lanceolata was identified as the methyl ester of an essential amino acid, L-leucine. Three amino acid derivatives were identified in the extracts of pheromone glands of the scarab beetle, Phyllophaga elenans. These were... 

Leal W. S. (1991) (R,Z)-5-(-)-Oct-l-enyl) Oxacyclopentan-2-one, the sex-pheromone of the scarab beetle Anomala cuprea. Naturwissenschaften 78, 521-523. 

The majority of insect and mammalian pheromones are small and relatively simple molecules with low polarity. Nonpolar polysiloxane phases such as 100% polysiloxane or 5% polyphenylmethyl siloxane are the preferred column for pheromone research due to a broad range, thermal stability, and long lifetime. Five per cent (phenyl)methylpolysiloxane columns were used in the identification of dodecenyl acetate and dodecenol, the sex pheromones of the citrus fruit borer, and anisole, the sex pheromone of the scarab beetle. A 100% polysiloxane column was used in the analysis of dodecenyl acetate, the female sex pheromone of the Asian elephant. 

Females of several species use (R)-5-[(lZ)-l-octenyl]oxacyclopentan-2-one, buibuilactone 69 [ 140-144]. The first y-lactone identified from a scarab beetle was (R)-5-[(Z)-l-decenyl]oxacyclopentan-2-one, japonilure 70, the female produced sex pheromone of the Japanese beetle Popillia japonica [145]. Both 69 and 70 are components of specific blends of several species [140-143]. The Japanese beetle is extremely sensitive to the non-natural enantiomer of his pheromone as little as 1% of the (S)-enantiomer inhibits the attractiveness of the pheromone [ 145]. With respect to species discrimination, this is particularly... 

Leal W. S., Matsuyama S., Kuwahara Y., Wakamura S. and Hasegawa M. (1992) An amino acid derivative as the sex pheromone of a scarab beetle. Naturwissenschaften 79, 184-185. 

Tada S. and Leal W. S. (1997) Localization and morphology of the sex pheromone glands in scarab beetles (Coleoptera Rutelinae, Melolonthinae). J. Chem. Ecol. 23, 903-915. 

Because synthetic ( )-87 was pheromonally inactive, Tumlinson et al. carefully studied in 1977 the relationship between the enantiomeric purity of 87 and its pheromone activity.60 They synthesized the enantiomers of 87, starting from the enantiomers of glutamic acid. The bioactive enantiomer is (/ )-(—)-87, and (5 )-(+)-87 severely inhibits the action of (R)-87. Accordingly, (R)-87 of 99% ee is only two-thirds as active as pure (R)-S7 that of 90% ee is one-third as active, that of 80% ee is one-fifth as active as pure (R)-87. Both (7v )-87 of 60% ee and ( )-87 were inactive. These results illustrate convincingly the importance of enantiomeric composition in chemical communication. Later in 1996, Leal found that the sex pheromone of the female scarab beetle (Anomala osakana) is (S )-87, while (R)-87 interrupts the attraction caused by (.S )-87,61 Thus, chirality accounts for species discrimination. 

The female produced long range sex pheromone of Migdolus fryans is AT-[(2 S)-2-methylbutyl]-(2S)-2-methylbutyramide 185 [345]. The acyl part as well as the alkyl part may be derived from isoleucine. Interestingly, this amide is accompanied by the ethyl ester of N-formyl isoleucine, which is also known from the scarab beetle, Phyllophaga elenans [181]. This amino acid derivative proved to be not attractive for both species its biological significance remains to be clarified. 

The female-produced sex pheromones of several different species of scarab beetles have been identified, and they include a wide variety of structures. Although many appear to be fatty acid-derived, isoprenoid- and amino acid-derived compounds are also represented (reviewed in Leal, 1998b, 1999). 

The scarab beetle Osmodenna eremita and its larval predator, the click beetle Elaterferrugineus, are known as indicators of the species richness of insect fauna of hollow deciduous trees in Northern Europe. (R)-4-Decanolide 13 (Figure 4) is the male-produced sex pheromone of 0. eremita 2 Lactone 13 is also employed by E. ferrugineus as a kairomone for the detection of tree hollows containing the larvae of 0. eremita u... 

Males of the scarab beede Amphimatton solstitialis are attracted to the pheromone (/ )-3-hydro.xy-2-butanone (A62), released by both males and females.368 Although the ( -enantiomer and 2,3-butanediol (A4) are also produced, they were not active in the field. 3-Hydroxy-2-butanone of unknown enantiomeric composition is the major sex pheromone component of male cockroach Leucophaea mademe2m The rhinoceros beetle Scapanes australis uses a 84 12 4 mixture of 2-butanol (A61) (R/S 67 33), 3-hydroxy-2-butanone (A62), and 2,3-butanediol (A4, RJl/S,S/meso 43 17 40), whereas the pheromone of another rhinoceros beetle Strategus aloeus is a 95.5 4.0 0.5 mixture of2-butanone (A63), 3-pentanone (A66), and 1-methylpropyl acetate (A64). As mixtures of all components of the natural secretion were used in this study, it is not clear whether all compounds really possess pheromonal activity.369... 

Females of several other species of scarab beetles use methyl esters of L-iso-leucine 83 and l-valine 84 as sex pheromones [179,180]. In Phyllophaga elenans, apart from 83, the corresponding N-formyl- and AT-acetyl derivatives have been... 

---