Identification of species-specific spectral emittance and hydrocarbon composition of members in the Chrysobothris genus

The Chrysobothris genus contains several species of wood-boring beetles that are difficult to positively identify from one another without genetic analyses or dissection of male genitalia. Species and sexes appear to play a role in color attraction by this groups of beetles. Previous studies have found that males were more highly attracted to a red hue (the purity of a base color) and a peak reflectance at longer wavelengths (i.e. red and near infrared). Contrastingly, females were more attracted to violet hues and showed no relationship to peak reflectance. This differentiation of attraction between sexes may influence mate seeking behaviors. Furthermore, individual species showed differential attraction to various peak reflectance’s, hues, other traits of color. Species may emit differentiating spectra in the UV and VIS spectrum that is used for the location of conspecifics. These changes in spectral emission recognition occur in other closely related beetles (e.g. emerald ash borer) due to small pits on the cuticles of elytra, the morphological structure of these pits, and surface waxes (e.g. hydrocarbon profile). We analyzed five males and five females from 10 FAB species to understand patterns of hydrocarbon composition, elytra pit morphology, and spectral emissions. Identifying differences in cuticular hydrocarbons and spectral emissions may offer scientists a better way to identify the various species without genetic assistance. These differences may also give insight to host-preference and a better understanding of each species’ ecology and behavior.