Differentiation of Male,Female and Dead Silkworms While in the Cocoon by near Infrared Spectroscopy

The feasibility of using a non-destructive method to differentiate male (M), female (F) and dead (D) worm cocoons of silkworms has been studied with near infrared (NIR) spectroscopy over the region 680–1235 nm on a sample set of 205 fresh cocoons. On the basis of the spectral data of the first and second derivatives, characteristic vectors were extracted by multiple linear regression and a Bayes critical function was established. This function was used to test 375 samples and the success rate was 95.7%. This method of sex judging is thus preferable to the conventional use of the weight and size of a cocoon which achieved a success rate of only 82.9% on the same samples. Experiments showed that the differences between NIR spectra of M and F cocoons mainly result from the property of silkworm cocoons rather than their incunabulum.