Effects of some Extracts on Growth Characters of Mulberry Silkworm "Bombyx mori L."

Two hybrids of silkworms, imported from Bulgaria, and local hybrid were used during the work. Six alcoholic extracts (Moringa, Rosemary, Garlic, Cestrum durant "Bostachia", mulberry silkworm, and silk glands, and four aqueous extracts (Moringa, Rosemary, Garlic, and Cestrum durant, were tested on imported and local hybrid of silkworm. Mulberry leaves were sprayed with (1%) of these extracts and offered to 4^th and 5^th instar larvae. The following growth characters were detected and calculated: initial, final average and range of 5^th instar weight, growth index, silk glands weight, ratio between silk glands and larval weight, pupal weight, fresh and cocoon, shell weight and cocoon shell ratio % was calculated. Using of aqueous extract of Rosemary on imported silkworms leads to an increase in cocoon shell ratio %. Concerning local hybrid this increment was detected in C. durant, Moringa, and Garlic treatments. All tested aqueous extracts increased cocoon shell ratio % in local hybrid. Generally, in imported hybrid, the only increment in cocoon shell ratio % was in aqueous extracts of Rosemary treatment. However, in local hybrid this increment was found in alcoholic extracts of Moringa, Garlic, C. durant. This reflects more response of local hybrid as compared with imported one. Also, response to aqueous extracts was more than the alcoholic extracts. Thus, using of local hybrid of silkworm and treatment of mulberry leaves with aqueous extract is considered be available easier and cheaper for feeding of mulberry silkworms, in Egypt.