title: Defensive chemicals of two species of Trachypachus Motschulski.
abstract: Analyses of pygidial gland contents of two species of a previously uninvestigated family of beetles (Trachypachidae) by Gas Chromatography-Mass Spectrometry (GC-MS) revealed that their chemistry is similar to that reported from many members of the family Carabidae. Nevertheless, the composition of defensive gland fluids of the two species Trachypachus slevini and T. gibbsii differs sufficiently to distinguish between the two species solely on the basis of their defensive chemistry. The major components of T. slevini glandular fluid are methacrylic, tiglic, and octanoic (= caprylic) acids, together with the hydrocarbon (Z)-9-pentacosene. In contrast, the glandular contents of T. gibbsii contain a rather unique mixture of polar and nonpolar compounds, the principal constituents of which are methacrylic and ethacrylic acids (= 2-ethylacrylic acid), together with 2-phenylethanol, 2-phenylethyl methacrylate, 2-phenylethyl ethacrylate, and (Z)-9-pentacosene.
authors.affiliation: Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, New Jersey 07030, USA. aattygal@stevens.edu
authors.forename: Athula B
authors.initials: AB
authors.lastname: Attygalle
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Wu
authors.forename: Josef
authors.initials: J
authors.lastname: Ruzicka
authors.forename: Sheetal
authors.initials: S
authors.lastname: Rao
authors.forename: Silvina
authors.initials: S
authors.lastname: Garcia
authors.forename: Kithsiri
authors.initials: K
authors.lastname: Herath
authors.forename: Jerrold
authors.initials: J
authors.lastname: Meinwald
authors.forename: David R
authors.initials: DR
authors.lastname: Maddison
authors.forename: Kipling W
authors.initials: KW
authors.lastname: Will
mesh_terms: D000818:Animals; D002210:Caprylates / Q000032:analysis; D001517:Coleoptera / Q000502:physiology*; D003437:Crotonates / Q000032:analysis; D005088:Exocrine Glands / Q000737:chemistry* / Q000502:physiology*; D008401:Gas Chromatography-Mass Spectrometry; D045782:Hemiterpenes; D006838:Hydrocarbons / Q000032:analysis; D008689:Methacrylates / Q000032:analysis; D008970:Molecular Weight; D012015:Reference Standards; D013045:Species Specificity; D014835:Volatilization
chemical_list: D002210:Caprylates; D003437:Crotonates; D045782:Hemiterpenes; D006838:Hydrocarbons; D008689:Methacrylates; C008384:methacrylic acid; C009489:tiglic acid; C031492:octanoic acid