The Bright Side of the Tiger: Autofluorescence Patterns in Aedes albopictus (Diptera, Culicidae) Male and Female Mosquitoes.

Light-based events in insects deserve increasing attention for various reasons. Besides their roles in inter- and intra-specific visual communication, with biological, ecological and taxonomical implications, optical properties are also promising tools for the monitoring of insect pests and disease vectors. Among these is the Asian tiger mosquito, Aedes albopictus, a global arbovirus vector. Here we have focused on the autofluorescence characterization of Ae. albopictus adults using a combined imaging and spectrofluorometric approach. Imaging has evidenced that autofluorescence rises from specific body compartments, such as the head appendages, and the abdominal and leg scales. Spectrofluorometry has demonstrated that emission consists of a main band in the 410-600 nm region. The changes in the maximum peak position, between 430 nm and 500 nm, and in the spectral width, dependent on the target structure, indicate the presence, at variable degrees, of different fluorophores, likely resilin, chitin and melanins. The aim of this work has been to provide initial evidence on the so far largely unexplored autofluorescence of Ae. albopictus, to furnish new perspectives for the set-up of species- and sex-specific investigation of biological functions as well as of strategies for in-flight direct detection and surveillance of mosquito vectors.