Construction of Life-Tables for some Hybrid Crosses of Mulberry Silkworm (Bombyx Mori Linnaeus) Under Lab Condition

Abstract

The mass rearmg of silkworm for commercial production of silk is called as "Sericulture". This is a labour intensive, agro-based cottage industry, ideally suited not only to India but also to all developing countries of tropical region. Mulberry silk worm (Bombyx mori Li1m.) is a monophagous insect species and feeds on mulbeny plant leaves. The Present study entitled "Construction of life tables for some hybrid crosses of mulberry silkworm (Bombyx mori L.) under lab condition" was carried out at Sericulture Research, Demonstration and Training Unit lab, Department of Entomology, Sardar Vallabhbhai Patel University of Agriculture and Technology Modipuram, Meerut (U.P.) during summer 2012- 13. To record the data on different life parameters or Bombyx mori, three types of lifetable were constructed, (i) age specific life table, (ii) stage specific life table and (iii) life and fertility table for female. The age specific life table revealed that the age specific survivorship of two mulberry silkworm hybrid crosses viz, NistarixNistari and KC2xFC1 were almost same, with little differences. The Bombyx mori L. hybrid cross NistarixNistari took the shortest time 37 and 40 days to complete its generation, while hybrid cross KC2xFC1 required the maximum time, 40 and 42 days at control condition as well as at room temperature respectively. The highest apparent mortality was recorded on NistarixNistari 16% and 13%, whereas lowest 11% and 13% on KC2xFC1 at control as well as at room temperature respectively. The potential fectmdity was recorded 352 and 297 eggs/female on NistarixNistari and lowest 318 and 282 eggs/female on KC2xFC1 at control condition and room temperature respectively. Based on the results obtained from the present study, it may be concluded that among the hybrids cross of mulberry silkworm NistarixNistari was the most suitable hybrid cross for the sericulture growers ofU.P.