Effect of Climate Factors on the Growth and Development of Silkworm in West Bengal, India
Kunal Sarkar
*
Udaychandpur High School (H.S), Jibanti, Kandi, Murshidabad, Pin-742136, West Bengal, India.
Soumik Chatterjee
Central Silk Board, Central Silk Technological Research Institute, Regional Silk Technological Research Station, Malda, India.
*Author to whom correspondence should be addressed.
Abstract
Silkworm is a major economic insect of India as well as in West Bengal, which produces silk, considered as queen of textile fibres. Like any other insect, the development and reproduction of silkworms are greatly influenced by a variety of nutritional and climatic factors. The major silk-producing insect, Bombyx mori, is a domesticated and delicate insect. Improper maintenance of nutritional and climatic factors affects the genotypic expression in the form of phenotypic output of the silkworm crop, such as cocoon weight, shell weight, and cocoon shell ratio. But it is not easy to manage silkworm rearing in West Bengal due to the prevalence of high temperature and high humidity most of the time during the silkworm rearing. These climatic factors also influence the various nutritional factors. For example, humidity in the rearing room may affect the types of leaves fed to silkworm larvae in different instars. The present study discusses the role of various climatic factors on the growth and development of the silkworm, and consequently, their effect on various nutritional factors. This study also indicates future strategies to be taken for the management of various climatic factors for a successful cocoon crop in West Bengal. Shoot feeding is always beneficial than individual leaf feeding, particularly in the latter stage. In case of individual leaf feeding, particularly in the latter stages when silkworms become much bigger try to crawl on individual leaves for feeding, and leaves virtually go lower side due to the pressure of the silkworm and the silkworm cannot fully utilize the leaves. It is concluded that by considering all the requirements of silkworm larvae November is the best season for crossbreed rearing in West Bengal due to prevailing of comparatively lower temperature in the environment but for crossbreed rearing in November, it is important to prepare seed crop of its bivoltine component in September, but due to climatic disadvantages it is not possible to rear bivoltine seed crop in September in most part of West Bengal, it is the major disadvantages of sericulture in West Bengal So, it is important to develop bivoltine seed zone in West Bengal to ensure supply of bivoltine seed cocoon throughout the year.
Keywords: Silkworm, climate, cocoon crop, silk spinning