Toxicological effect of medicinal plant extracts used against mulberry powdery mildew on growth, development of silkworm (Bombyx mori L.), cocoon and silk quality parameter
SE Manjunatha, VB Sanath Kumar, N Kiran Kumar and Venkatesh
The different medicinal plant extracts applied against mulberry powdery mildew were tested for their effect on growth and development of silkworm, cocoon and silk quality parameters. It was found that when treated leaves were fed one day after treatment highest larval mortality (25.00%) was recorded in Azadirachta indica extractat 15 percent but it was very low in case of Zingiber officinale (4.99%). At same concentration, the larval death steadily decreased in all the treatments except Azadirachta indica with15.02 percent, when fed two days later, whereas, no mortality noticed in case of Zingiber officinale at two days after treatment. All the plant extracts tested had no toxic effect at three days after treatment. Maximum larval weight (29.42g), larval length (5.37cm), cocoon weight (12.87g), pupal weight (9.46g), shell weight (3.41g), shell ratio (26.49%) and maximum cocoon yield (450.45g) was observed in Zingiber officinale at 15% which was significantly superior over control treatment in all parameters. The increased larval weight in Zingiber officinale treated silkworms might be due to stimulatory effect of ginger on protein synthesis in the silk gland during larval period. The silk quality viz., filament length of 884.02 m and the denier was finer (1.83%) in silkworm larvae fed with Zingiber officinale fortified mulberry leaves was better compared to all other treatments followed by Lantana camara and Acorus calamus.
SE Manjunatha, VB Sanath Kumar, N Kiran Kumar, Venkatesh. Toxicological effect of medicinal plant extracts used against mulberry powdery mildew on growth, development of silkworm (Bombyx mori L.), cocoon and silk quality parameter. J Entomol Zool Stud 2017;5(6):872-876.