Cuticular hydrocarbons as chemotaxonomic characters of pine engraver beetles (Ips spp.) in the grandicollis subgeneric group

• Published in: Journal of chemical ecology 1997-04, Vol.23 (4), p.1053-1099
• Main Authors: Page, M. (Pacific Southwest Research Station, USDA, Forest Service, Albany, CA.), Nelson, L.J, Blomquist, G.J, Seybold, S.J
• Format: Article
• Language: English
• Subjects: Alkenes; Animal behavior; Biological and medical sciences; CHEMOTAXONOMY; CHIMIOTAXONOMIE; CUTICLE; Fundamental and applied biological sciences. Psychology; Gas chromatography; HIDROCARBUROS; HYDROCARBONS; HYDROCARBURE; Insecta; Insects; Invertebrates; IPS GRANDICOLLIS; Mass spectrometry; Nucleic acids; QUIMIOTAXONOMIA; Systematics. Geographical distribution
• ISSN: 0098-0331; 1573-1561
• DOI: 10.1023/b:joec.0000006388.92425.ec

Cuticular hydrocarbons were extracted, identified, and evaluated as chemotaxonomic characters from all species of adult Ips pine engraver beetles in the grandicollis subgeneric group. The grandicollis group consists of Ips grandicollis (Eichhoff), I. cribricollis (Eichhoff), I. lecontei Swaine, I. montanus (Eichhoff), I. paraconfusus Lanier, I. confusus (LeConte), and I. hoppingi Lanier. In order to provide outgroups for a phylogenetic analysis, cuticular hydrocarbons were also analyzed from Orthotomicus caelatus (Eichhoff), I. latidens (LeConte) (latidens subgeneric group), and I. pini (Say) (pini subgeneric group). Two hundred forty-eight hydrocarbon components were identified by gas chromatography-mass spectrometry. The members of the grandicollis group provided 206 of these compounds. The components represented eight classes: n-alkanes, alkenes, alkadienes, terminally branched methylalkanes, internally branched methylalkanes, dimethylalkanes, trimethylalkanes, and tetramethylalkanes. Different populations of O. caelatus, I. grandicollis, I. lecontei, I. montanus, I. paraconfusus, I. confusus, and I. hoppingi provided no evidence for interpopulational variation in cuticular hydrocarbons. Single populations only were analyzed for I. latidens, I. pini, and I. cribricollis. Sexual dimorphism in cuticular hydrocarbons occurred only in I. lecontei where females produced eight unique components with a pentatriacontane parent chain. Several phylogenetic analyses based on hydrocarbon phenotypes agreed in general with the established morphologically based system of relatedness and with published phylogenies reconstructed from protein and nucleic acid characters Nearly all hydrocarbon analyses suggested a close relationship between I. grandicollis and I. cribricollis; between I. lecontei and I. montanus; and among the sibling species I. paraconfusus, I. confusus, and I. hoppingi.