Comparative Evaluation of Benchtop and Portable Near-Infrared Spectrometers for Predicting the Age and Blood Feeding History of Aedes aegypti

This study is a comparative assessment of a more affordable handheld spectrometer (NIRvascan) with the traditional Labspec 4i spectrometer for predicting the chronological age and blood feeding history of female <i>Aedes aegypti</i> mosquitoes reared in the lab. Three separate cohorts of laboratory-reared <i>Ae. aegypti</i> mosquitoes were reared and collected at three age groups (1-, 10- and 17-days old). A model developed using Artificial Neural Networks (ANN) with spectra collected by the Labspec 4i NIR spectrometer predicted the age of <i>Ae. aegypti</i>, classifying them into two groups (< or ≥ 10 days) with a predictive accuracy of 94% (N = 366) whereas an ANN model developed using spectra collected by the NIRvascan spectrometer predicted the age of <i>Ae. aegypti</i> mosquitoes, classifying them into the same age group with a predictive accuracy of 90% (N = 290). ANN models developed for predicting the blood feeding history of mosquitoes were 82.8% (N = 308) and 71.4% accurate (N = 300) when Labspec 4i and NIRvascan were used, respectively. This is the first study to demonstrate that a handheld NIR instrument operated by a smart phone could potentially be used for predicting entomological parameters of mosquitoes.