Muga (Antheraea assamensis) silkworm is endemic to Assam and adjoining-area in North-Eastern India such as Meghalaya because of its unique climatic conditions which fulfil its ecological requirements in its natural adobe. The major problem in A. assamensis is that, it is more vulnerable to disease infestation due to outdoor nature of rearing and because of this factor, there is increment in mortality rate of Muga silk worms and reduction in production, according to estimated quantity. The major diseases occurring North-Eastern states of Assam and Meghalaya are Flacherie, Pebrine and Muscardine.
Flacherie is a bacterial disease followed by secondary infection of opportunistic infectious bacteria causes more damage to Muga silkworm. This disease is more vulnerable to sudden fluctuation in temperature (high humidity and high temperature) coupled with poor quality food and this disease prevails in all the season, but it is highest in summer season (Bhodia and Aherua, these terms are Assamese words used to refer particular season). In Muga the optimum temperature and humidity required for their rearing is 15o to 25o C and humidity maximum of 75%-85%, beyond this favorable condition Muga silkworms cannot survive. It is found that fluctuation in temperature and humidity adversely affects the silkworm rearing. Fifteen days average of maximum temperature and maximum relative humidity during rearing season can be effectively used to predict Flacherie infestation at 5 to 10 days in advance prior to harvest.
Model developed using fifteen days average Maximum Temperature and Maximum Humidity before 5 days of harvest which can significantly predict Flacherie incidence with R2=0.776 , p<0.0005. Both the variables added statistically significantly to the prediction, p<0.05. This model can explain approximately 78% of variance in flacherie incidence due to these two variables.
Model developed using fifteen days average Maximum Temperature and Maximum Humidity before 10 days of harvest which can significantly predict Flacherie incidence with R2=0.623 , p<0.0005. Both the variables added statistically significantly to the prediction, p<0.05. This model can explain approximately 62% of variance in flacherie incidence due to these two variables.
✓ The Muga silkworm rearing should be away from agricultural land, built-up area, factories etc, as disease incidence highly correlate with increase in anthropogenic activity.
✓ Similarly, Muga farms surrounded by dense forest area are beneficial for optimal growth of silkworm due to balance in land surface temperature.
✓ The aspect of the farm must avoid south facing in hot and humid climate as Muga silkworms are shade lovers.
✓ The Muga silkworm rearing farmers , should take proper precautionary measures to avoid disease out-break during the period when temperature exceed 30°C with relative humidity exceeding 80% for few consecutive days.
The "golden silk",Muga is found exclusively in the rainforest of the Himalayan foothills in North Eastern India, especially in Assam and Meghalaya due to unique climatic conditions. It feeds on som (Persea bombycina) and Soalu (Litsea Polyantha) as primary food plant and few other plants as secondary and tertiary It is reared outdoor and it suffers from a large number of problems such as unfavorable weather, infection from other creatures and outbreak of various disease.The Muga culture is of economic importance and is closely associated with the life, tradition and culture of tribal people. The muga silk productivity is greatly affected by enormous pests and disease problems. Further the affects are more pronounced in recent days due to human interventions in deteriorating. Muga ecosystem resulting in rapid climate changes. There is a great probability of significant effects of increased climatic variability on the incidence of silkworm diseases if the changes in climate happen to coincide with the critical growth period of silkworm. Now it has become essential to assess the land cover, environmental condition and various climatic parameters which are likely to cause incidence of silkworm diseases.
North eastern Space Applications Cenrtre, Department of Space in collaboration with Central Muga Eri Research & Training Institute had taken up a project entitled “Development of Decision Support System for Early Warning of Selected Muga Silkworm Disease and Pests with Geospatial Techniques” to identify the various disease causing parameters and evolve strategies to overcome them in the form of decision support system.Since the study is first ever of its kind in Muga sericulture, the experimental results form an integral part of decision support system. Model developed in this study to predict percent flacherie infestation will be very useful for the farmers to take proper precautionary measures to avoid disease out-break atleast 5-10 days in advance. Recommendations and model developed shows the potential of geospatial technology for farm level planning and management through a geoportal. Mobile application has been developed for an early warning of percent flacherie infestation mainly to collect data and validate the model developed under this project by the restricted users. More emphasis has been given for linking to SILKS geoportal to have wider use by the farmers as well as different stakeholders of the sericulture industry in the state in future.
Dr. Jonali Goswami, Scientist SF
North Eastern Space Applications Centre,
Department of Space,
Government of India,
Umiam 793103 (Meghalaya)
Contact: +91-364 2308716
Email id: jonali[dot]goswami[at]gmail[dot]com
Dr. D.K. Gogoi, Scientist-D
Central Muga Eri Research & Training Institute,
Central Silk Board, Ministry of Textiles,
Government of India,
Lahdoigarh, Jorhat-785700, Assam
Contact: 91 376-2335513, 2335124 (O)
Email id: gkdeep[at]gmail[dot]com