Patterns of diversity in Psocoptera using near infrared spectroscopy

Abstract: Metabolomics, the analysis of the global metabolic profile of organisms, is a novelapproach to study diversity in insects by near infrared spectroscopy (NIRS). The NIRS is a typeof vibrational spectroscopy which uses light energy at wavelengths from 750 to 2500nm.Interaction between light and matter at such frequencies generates qualitative and quantitativeinformation at the molecular level. Metabolomic usually provides more extensive data at a lowercost than genomics and other molecular methods. The objectives of this research are todemonstrate that NIRS based metabolomics is a valuable and non-destructive tool and to propose,test, and organize a hypothesis on diversity patterns and discrimination of Psocoptera species. Sixspecies (four specimens each) from the genus Liposcelis (Psocoptera: Liposcelidae) and onespecies of Lepinotus (Psocoptera: Trogiidae) were tested. Each specimen was placed on a diffusereflectance accessory of a NIR spectrometer to obtain the respective spectrum. All spectra wereanalyzed by combined methods of multivariate analysis using the technique of crossed validationfor the multivariate models. The analysis discriminated the seven species without significantoverlapping among the species spectral patterns. The NIRS revealed quantitative variation in themetabolomic profile both at intra and inter-specific levels based on dispersion patterns ofindividual specimens. We assume NIRS to be, by concept and potential application, the true lifebarcoding that may be associated with morphological, genomic, and biogeographic data to revealsignificant information of a given taxonomic hierarchy. NIRS produces a matrix of spectral datathat can, biologically speaking, tell the life history of not only psocids but of any other organism.