title: Exocrine secretions of wheel bugs (Heteroptera: Reduviidae: Arilus spp.): clarification and chemistry.
abstract: Wheel bugs (Heteroptera: Reduviidae: Harpactorinae: Arilus) are general predators, the females of which have reddish-orange subrectal glands (SGs) that are eversible like the osmeteria in some caterpillars. The rancid odor of Arilus and other reduviids actually comes from Brindley's glands, which in the North (A. cristatus) and South (A. carinatus) American wheel bugs studied emit similar blends of 2-methylpropanoic, butanoic, 3-methylbutanoic, and 2-methylbutanoic acids. The Arilus SG secretions studied here are absolutely species-specific. The volatile SG components of A. carinatus include (E)-2-octenal, (E)-2-nonenal, (E)-2-decenal, (E,E)-2,4-nonadienal, (E)-2-undecenal, hexanoic acid, 4-oxo-nonanal, (E,E)-2,4-decadienal, (E,Z)-2,4- or (Z,E)-2,4-decadienal, and 4-oxo-(E)-2-nonenal; whereas in A. cristatus the SG secretion contains beta-pinene, limonene, terpinolene, terpinen-4-ol, thymol methyl ether, alpha-terpineol, bornyl acetate, methyl eugenol, beta-caryophyllene, caryophyllene oxide, and farnesol. Arilus spp. SG secretions may be sex pheromones, but verification of this hypothesis requires further testing.
authors.affiliation: Affiliate Department of Entomology, University of California, Davis, CA, USA. drjeffaldrich@gmail.com
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Aldrich
authors.affiliation: USDA-ARS Invasive Insect Biocontrol & Behavior Laboratory, 10300 Baltimore Avenue, Bldg. 007, rm301, BARC-West, Beltsville, MD 20705, USA.
authors.forename: Kamlesh R
authors.initials: KR
authors.lastname: Chauhan
authors.affiliation: USDA-ARS Invasive Insect Biocontrol & Behavior Laboratory, 10300 Baltimore Avenue, Bldg. 007, rm301, BARC-West, Beltsville, MD 20705, USA.
authors.forename: Aijun
authors.initials: A
authors.lastname: Zhang
authors.affiliation: Universidade Federal do Paraná, Departamento de Química, Laboratório de Semioquímicos, CP 19081, 81531-980 Curitiba, PR, Brazil.
authors.forename: Paulo H G
authors.initials: PH
authors.lastname: Zarbin
mesh_terms: D000818:Animals; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D020062:Heteroptera / Q000378:metabolism*