Chromotrope-2r and naphthalene blue black stains for easy detection of Nosema mylittensis spore infecting tropical tasar silkworm, Antheraea mylitta D

Pebrine disease caused by Nosema mylittensis in tropical tasar silkworm, Antheraea mylitta D. is highly contagious and more prevalent due to its transovarial transmission and death of worms. Pebrine detection during mother moth examination in grainages is strenuous. Staining of pebrine for easy detection in tasar sericulture is largely unexplored. The aim of the present study was to identify suitable stains for easy identification of N. mylittensis spores during microscopic examination of mother moth. The stains which are used for staining and identification of pathogens in microbiological field and clinical laboratories were selected and used. Among sixteen stains used, six stains viz Wright stain, Nigrosin, Amido black, Bismark brown, Chromotrope-2R and Naphthalene blue black have shown the staining of N. mylittensis spores. However, Chromotrope-2R and Naphthalene blue black found more suitable because the spores took prominent red and blue colour respectively and easy to identify from cellular debris and other non pebrine artifacts. Other stains used have shown partial staining of N. mylittensis spores and the spores are very difficult to differentiate from debris and other artifacts in the smear. Hence, Chromotrope-2R and Naphthalene blue black may be used for staining and easy identification of N. mylittensis spores during mother moth examination.