Imaging and spectral analysis of autofluorescence distribution in larval head structures of mosquito vectors

Autofluorescence (AF) in mosquitoes is currently poorly explored, despite its great potential for investigation of body structures and biological functions. Here, for the first time AF in larval heads of two mosquitoes of key public health importance, Aedes albopictus (Skuse) and Culex pipiens Linnaeus (Diptera: Culicidae), is studied using fluorescence imaging and spectrofluorometry, similar to a label-free histochemical approach. While presenting a generally conserved distribution, AF emission signals show differences in their localization both between mouth brushes and antennae of the two species. The blue AF ascribable to resilin is detected in a more extended area at the antennal bases in Cx. pipiens than in Ae. albopictus, suggesting a potential need to support different antennal movements. The AF spectra, larger in Cx. pipiens than in Ae. albopictus, indicate differences in material composition and molecular properties between the two species likely relatable to their biology, including diverse feeding and locomotion behaviors, with implications for vector control.