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Abstract The art of silk production is called sericulture that comprises cultivation of mulberry, silkworm rearing and post cocoon activities leading to production of silk yield. Sericulture provides gainful employment, economic development and improvement in the quality of life to the people in rural area and therefore it plays an important role in antipoverty program and prevents migration of rural people to urban area in search of employment. Hence several developing countries all over the world have taken up sericulture to provide employment to the people in rural areas (Walaa Nageip, 2018). The silkworm eats only mulberry leaves to make its cocoon, producing the silk. Mulberry leaves are rich in protein and amino acids (Machii, 1989). It is known that there is a high correlation between the leaf protein level and production efficiency of the cocoon shell, which means the cocoon shell weight of the total amount of mulberry leaves consumed by the silkworm (Machii and Katagiri, 1991). Sericulture means cultivation of silkworms which finally produces silk. The word silk sounds luxury and class. Until today, no other fabric can match it in luster and elegance. As long as human desire for silk garments continues, the demand for sericulture activity remains. Silk is the queen of textile and naturally produced animal fiber. Scientists have tried alternative hosts for the rearing of mulberry silkworm and many of them used mineral elements as food supplements. They found positive impact of supplements on the silkworm growth and silk production (Ahmed,1998). The Egg hatching rhythmicity in silkworm, Bombyx moriwas studied under natural day (LD 12:12), reverse light-dark cycles (DL 12:12), continuous light (LL) and dark (DD) conditions. A distinct diurnal hatching rhythm was observed under alternate light-dark cycles (LD/DL). Under LL also, the rhythm was diurnal with a near dampingout expression. Hatching was completed in a single day, occurring on the 9th day of oviposition under LD/DL cycles, and on the 10th day under DD. Under LL, however, it occurred for two consecutive days, starting with stray hatching on the 10th day and extending to the 11th day of oviposition. Low light intensities resulted in less hatching durations while high light intensities increased them (Reddy et al., 1998). The present study was carried out during spring season of 2017 in Sericulture Laboratory, Economic Entomology Department Faculty of Agric., Menuofia University to evaluate the effect of light time and color on some biological, technological and physiological characters of silkworm, Bombyx mori L. |