title: Differences in spectral selectivity between stages of visually guided mating approaches in a buprestid beetle.
abstract: Spectral mating preferences were examined in male Agrilus angustulus (Buprestidae: Coleoptera), a member of a taxon known for its high species diversity and striking metallic coloration. The spectral emission profile of a typical A. angustulus female displays low chroma, broadly overlapping that of the green oak leaves they feed and rest upon, while also including longer wavelengths. To pinpoint behaviorally significant spectral regions for A. angustulus males during mate selection, we observed their field approaches to females of five Agrilus planipennis color morphs that have greater chroma than the normal conspecific female targets. Agrilus angustulus males would initially fly equally frequently toward any of the three longest wavelength morphs (green, copper and red) whose spectral emission profiles all overlap that of typical A. angustulus females. However, they usually only completed approaches toward the two longest wavelength morphs, but not the green morphs. Thus, spectral preference influenced mate selection by A. angustulus males, and their discrimination of suitable targets became greater as these targets were approached. This increasing spectral discrimination when approaching targets may have evolved to allow female emissions to remain somewhat cryptic, while also being visible to conspecifics as distinct from the background vegetation and heterospecific competitors.
authors.affiliation: The Pennsylvania State University, Department of Entomology, University Park, PA 16802, USA mjd29@psu.edu.
authors.forename: Michael J
authors.identifier: http://orcid.org/0000-0002-3055-3533
authors.initials: MJ
authors.lastname: Domingue
authors.affiliation: United States Department of Agriculture, Animal and Plant Health Inspection Service, Plant Protection and Quarantine, Brighton, MI 48116, USA.
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Lelito
authors.affiliation: The Pennsylvania State University, Department of Entomology, University Park, PA 16802, USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Myrick
authors.affiliation: NARIC Forest Research Institute, Department of Forest Protection, Mátrafüred 3232, Hungary.
authors.forename: György
authors.initials: G
authors.lastname: Csóka
authors.affiliation: NARIC Forest Research Institute, Department of Forest Protection, Mátrafüred 3232, Hungary.
authors.forename: Levente
authors.initials: L
authors.lastname: Szöcs
authors.affiliation: Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest 1022, Hungary.
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Imrei
authors.affiliation: The Pennsylvania State University, Department of Entomology, University Park, PA 16802, USA.
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Baker
keywords: Buprestidae; Color vision; Crypsis; Flight; Species recognition