Aging immature Diptera using hyperspectral remote sensing

Wednesday, November 13, 2013: 2:00 PM
Meeting Room 18 B (Austin Convention Center)
Jodie Warren , School of Criminology, Simon Fraser University, Burnaby, BC, Canada
Margaret Kalacska , Department of Geography, McGill University, Montreal, QC, Canada
Gail Anderson , School of Criminology, Centre for Forensic Research, Simon Fraser University, Burnaby, BC, Canada
Methods of estimating the minimum elapsed time since death from immature dipteran development are at present based on the minimum tenure of developing insects on the remains.  The immature larvae and pupae develop at predictable rates and the time taken to reach the stage of development is used as a post-mortem interval estimate. Some stages are quite lengthy and unfortunately can only offer a broad estimate.  The use of hyperspectral remote sensing in forensic entomology is relatively novel; however, remote sensing is being applied in entomology as well as other forensic sciences on a regular basis. To reduce this rudimentary estimate, spectral measurements were taken daily of the developing insects from second instar until adult emergence in order to provide a distinguishing spectral signature between the days of development within the immature stages. The spectrometer recorded measurements of reflected radiation which spanned 325- 1025 nm for developing Protophormia terraenovae (Robineau-Desvoidey), The Northern Blow Fly.  Statistical tools were applied to complete the spectral analysis.  A smoothing filter was used and finally a forward feature selection designated the top 25 discriminating bands.  The spectral signature changed from day to day within the stages of immature development offering a promising way to estimate insect age and distinguish days of development within stages.