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Researcher Kavyashree, B. L.
Advisor Bhaskar, R. N.
Source KrishiKosh-Indian National Agricultural Research System
Content type Text
Educational Degree Master of Science (M.Sc.)
File Format PDF
Language English
Subject Domain (in DDC) Technology ♦ Agriculture & related technologies ♦ Insect culture
Subject Keyword Sericulture ♦ Effect of Different Sources of Horizontal Transmission of Bacterial Flacherie On Rearing
Abstract Silkworm being a poikilothermic, it is sensitive to varied climatic conditions affected by bacteria, fungi, viruses and protozoan. Flacherie disease of silkworm is caused by different species of bacteria and viruses, individually or in combination. Present study indicated a wide significant variation in per cent larval weight reduction on 5th day of V instar and before spinning (33.15 to 28.69, 31.79 to 25.51 % and 13.40 to 7.74, 13.03 to 7.36 %) when the fourth instar larvae inoculated with 10-5 and 10-7, respectively. ET50 for symptom expression and mortality revealed significant results for all the inoculated batches of PM X CSR2. The time taken for symptom expression was 9.01. 9.18; 7.01, 7.35 days and 9.51, 9.84; 7.63, 7.76 days recorded for contaminated faecal pellet and contaminated floor area in fourth and fifth instar inoculated batches fed with 10-5 and 10-7. However, contaminated faecal pellet inoculum administered batch deteriorated all the cocoon parameters viz., single cocoon weight, single shell weight and shell percentage at 10-5 and 10-7 dilutions by showing higher infection. The range was 0.851, 0.922 to 0.951, 1.00 g single cocoon weight, 0.105, 0.121; 0.120, 0.134 g single shell weight and the shell percentage of 14.13 to 16.93; 14.49 to 17.57 per cent was noticed in the batch inoculated with contaminated faecal pellet, respectively. The same decreased trend was seen in silk productivity, filament length and denier of PM x CSR2 administered with 10-5 and 10-7 dilutions. The study concluded that, contaminated faecal pellet was found to be the effective source of horizontal transmission of bacterial flacherie in both the instars. However, among two instars experimented, fifth instar was found to be more susceptible to horizontal transmission of bacterial flacherie.
Educational Use Research
Education Level UG and PG
Learning Resource Type Thesis
Publisher Place Bangalore
Size (in Bytes) 13.64 MB