RESUMO
The infrared spectra of the ethanol extracts of well-living silkworms and white muscardin silkworms of different seasons and breeds were analyzed by means of the sequential analysis in which two indexes, i. e. common peak ratio and variant peak ratio, were applied. The results showed that the ethanol extracts of white muscardin silkworm have a stable and distinct infrared spectrum. The spectral differences of the ethanol extracts between white muscardin silkworms and well-living silkworms were so obvious that the common peak ratio of them was no more than 63. 0%, and the variant peak ratio amounted to 41. 2%. The spectra of different breeds and seasons conformed with each other with a few small differences. The minimum common peak ratio of the spectra of different breeds was 76. 0%, and the maximal ratio was 92. 0%. The common peak ratio of the spectra of different seasons was 73. 1%. Infrared spectrometry was proved to be good for the identification of white muscardin silkworms and the differentiation of white muscardin silkworms of different breeds and seasons.