ISSN : 0975-3710
EISSN : 0975-9107
B.L. KAVYASHREE1*, R.N. BHASKAR2, S. HARISH BABU3
1Department of Sericulture, University of Agricultural Sciences, Bengaluru, 560 065, India
2Professor, Department of Sericulture, University of Agricultural Sciences, Bengaluru, 560 065, India
3Scientist-B, Regional Sericultural Research station, Central Silk Board, Kalimpong district, 734301, West Bengal, India
* Corresponding Author : kavyabevinakatti@gmail.com
Received : 02-07-2020 Accepted : 18-07-2020 Published : 30-07-2020
Volume : 12 Issue : 14 Pages : 10056 - 10058
Int J Agr Sci 12.14 (2020):10056-10058
Keywords : Bacterial flacherie, Defective cocoon percentage and pupal mortality, Horizontal transmission, PM x CSR2
Academic Editor : Naveen Kumar V M
Conflict of Interest : None declared
Acknowledgements/Funding : Authors are thankful to University of Agriculture Sciences, GKVK, Bengaluru, 560065, India
Author Contribution : All authors equally contributed
Flacherie disease of silkworm occurs in silkworm rearing and causes severe cocoon crop loss during summer and rainy seasons in all sericulture belts of Karnataka. The horizontal transmission of bacterial flacherie affect the growth and cocoon parameters of PM x CSR2. However, the different sources of inoculum administered to both fourth and fifth instar inoculated batches exhibited significant difference among treatments compared to control. The highest percent defective cocoon was recorded in batch inoculated with contaminated faecal pellet (36.11, 32.59 and 52.85, 28.17 %). It is vivid from the data that, the horizontal transmission of bacterial flacherie was increased the defective cocoon percentage after spinning. In general, the bacteria multiplied in a faster rate after the death of the larva. The pupal mortality was found significantly different in different sources of inoculum among fourth and fifth instar batches and also at two dilutions (10-5 and 10-7), respectively. Further, highest rate of pupal mortality was observed in contaminated faecal pellet (61.34, 54.88 and 59.29, 43.55 %) source of inoculum. It is attributed that, increased larval mortality and percent defective cocoons in the inoculated batch have resulted in increased pupal mortality in both the lots. As a secondary source of infection, bacteria within the cocoon cause pupal death before it is transforming to adult.
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