Abstract

LIDAR techniques have been extensively used for studies of aerosol particles. Fluorescence LIDAR was employed for studying natural bio aerosols, such as pollen, but also possible warfare agents [1]. Insects, being "large aerosol" particles clearly give rise to LIDAR returns. Recently, honey bees were studied by polarization reflectance LIDAR and their superior olfactory abilities were used in attempts to detect landmines [2]. Together with coworkers at the section for Animal Ecology, Lund University, we have initiated a project for using LIDAR, and in particular its fluorescence variety, to study the migration and distribution of two species of damselflies of special interest (Caloptoryx virgo and C. splendens). LIDAR techniques may be an interesting possibility to study the behavior and migration of insects, of relevance to ecology, agriculture and evolution [3]. This is especially true since known tracing techniques like GPS and RFID are unsuitable for insects, because of size and weight. The absorption of most insects is primarily explained by melanin and ommochromes, whereas the structural colors are considerably more characteristic for the species and genders, and are ideal for insect classification [4-7]. While the RADAR community for a long time has been exploring the opportunities for accessing structural interference "colors" [8], given by matched illumination, the LIDAR community mostly focused on chemical colors, using e.g. DIAL, LIF, LIBS [9]. We here report on spectroscopic results obtained in the laboratory and in short-range (60 m) LIDAR measurements on mounted, dried damselflies specimens, in attempts to classify genders and species. Elastic scattering as well as auto fluorescence and marker die fluorescence studies were performed. Laboratory work demonstrates imprints of structural color in the auto fluorescence spectra (Fig. 1). Possibilities for upcoming in vivo measurements during a summer field campaign are discussed.

© 2009 IEEE