Detection of parasitised fly puparia using near infrared spectroscopy

Near infrared (NIR) spectroscopy was used to identify house fly (Musca domestica L,.) puparia that contained viable parasitoids. Results derived from a partial least squares analysis of NIR spectra showed that about 80-90% of puparia containing parasitoids could be identified correctly. Difference spectra and beta coefficients indicated that absorption differences between parasitised and unparasitised puparia may have been due to moisture content and/or differences in composition of chitin or lipid components. Detection of viable hymenopterous parasitoids within puparia could assist commercial insectaries in delivering known quantities of parasitised puparia for biological control of house flies and other filth flies and in rapidly determining levels of parasitisation of these flies in confined livestock and poultry operations.