The tropical tasar silkworm, Antheraea mylitta, polyphagous sericigenous insect mostly found in the tropical areas of India. It is found in these regions as ecotypes or ecoraces. It feeds primarily on plants, a variety of secondary plants like Terminalia arjuna and T. tomentosa. Tasar culture is a traditional livelihood for lakhs of tribal populace in the areas of Jharkhand, Chhatisgarh, Orissa, Maharashtra, Andhra Pradesh, West Bengal and Uttar Pradesh. In the present study, the genetic diversity of these ecoraces is identified by DNA markers, namely simple sequence repeats (SSRs), most of which produced polymorphic bands.

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The commercial rearing of polyphagous Indian tasar silkworm, Antheraea mylitta Drury being practiced on naturally grown primary food plants like Terminalia arjuna, (Arjun) Terminalia tomentosa (Asan), and Shorea robusta (Sal) available in the tropical forests of central India , at times, is seriously affected by the disease-Pebrine, caused by Nosema sp., a microsporidian pathogen. The present investigation on comparative larval, silk gland weight and also cocoon parameters in Pebrine-free and Pebrine-infected ecorace of tasar silkworm Antheraea mylitta Drury (Daba TV), illustrates the tasar silkworm larvae infected with pebrine disease causing heavy losses to the economy of the silk industry. IntroductionThe tropical tasar culture is an important forest based agro-industry of producing vanya silk by rearing a wild silkworm, Antheraea mylitta Drury (Lepidoptera:Saturniidae), primarily on Terminalia arjuna (arjun), Terminalia tomentosa (asan) and Shorea robusta (sal) and secondarily on Lagerstroemia parviflora, Zizyphus mauritiana, Anogeis suslatifolia, Syzigium cumini, Careya arborea and Hardwickia binata, etc. Tasar Culture is "a forest based industry". It plays a major role in improving socio-economic status of tribal, weaker sections, landless people and women.The tasar food plant leaf quality in terms of nutrition can influence the health and growth of larvae, effective rate of rearing (ERR) and crop yields as it has correlation with the weights of cocoon, shell and silk ratio and can influence the crop economics. The leaf nutrient status of tasar food plant is fundamental not only for silk productivity, but also for its metamorphosis during life cycle and subsequent parental moth reproductive efficiency. The larval feeding status of any polyphagous commercial insect has impact on food storage and budgeting for biological activities so as to combat the adverse or to excel during favorable conditions (Reddy et al., January 2012).The diseases in silkworm are the major constraints

The populations of Indian tropical Tasar silkworm, Antheraeamylitta Drury, the semi-wild, sericigenous, lepidopteran insect are distributed in eco pockets of various States. These ecoraces vary in geography, topography, ecology, food plant flora and frequency of life cycle in latitudinal and altitudinal gradients. They exhibit diversity in phenotypic, behavioural, physiogenetic and commercial characters. In the present study, the SSR amplification of 7 silkworm strains/ecoraces (16 individuals in each, with seven primers which generated polymorphism) yielded a total of 887 bands, out of which 420 were (47.3 %) polymorphic. Most of the bands were observed within the range 130 to 500 base pairs which is in accordance with the allelic size of the primers taken for studies. The subsequent analysis of its population structure using these alleles revealed the formation of population clusters. The study suggests that these markers could be effectively utilized for identifying the genetic variability among tasar ecoraces.