Study of biological characteristics and productivity of the segregative generation of Silkworm hybrid Bombyx mori L. reared in Syrian coast

Abstract

The silkworm breeding, Bombyx mori L. is the most important economic activities in world. A study was carried out in 2018 in Syrian coast to study the biological characteristic and productivity of silkworm hybrid which is spreading in Syrian coast, under regular conditions of silkworm breeding (23-25 °C, and 65-80% relative humidity), at silkworm Laboratory in the Agricultural Scientific Research Center of Lattakia. The results indicated that the development period from egg hatching until adult emerging ranged 50-57 days, the longevity average of first, second, third, fourth, and fifth larval instars was 4.08±0.27,3.46±0.49, 6.24±0.44, 7.90±0.33, 9.16±0.9 and 10.16 ± 0.36 days respectively ,the longevity of male and female ranged 6-8 & 10-11 days respectively. Females laid 232 eggs in average. Results of productivity characteristic study showed that the weight average of pupa, cocoon and silk was 1.15±0.23, 1.47±0.28 & 0.30± 0.12g respectively, and the average of the filament length was 821±144m. Results also revealed presence of four forms of cocoon (spherical, elongated, oval, waisted).