Comparative Evaluation of a Portable and Benchtop Near-Infrared Spectrometers for Characterizing the Age and Blood Feeding History of <em>Aedes aegypti</em> Mosquitoes in the Lab

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 Aedes aegypti mosquitoes reared in the lab. Three separate cohorts of laboratory-reared Ae. aegypti mosquitoes were collected at 3 age groups (1, 10 and 17 days old). Models developed using spectra collected with Labspec 4i spectrometer predicted the age of Ae. aegypti into two groups (&amp;lt; or ≥ 10 days) with a predictive accuracy of 94% (N=366) whereas NIRvascan predicted the age of Ae. aegypti mosquitoes into the same age group with a predictive accuracy of 90% (N=290). Models developed for predicting 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 can be used for predicting mosquito traits related to the vectorial capacity. Our data indicates the feasibility of using both spectrometers for in-field application for analysis of mosquito samples to gain insights into population age structure.