SILKWORM PATHOLOGY

   

SCIENTISTS: 

 

1.   Dr. Satadal Chakraborty, Scientist-C 

 

MANDATE:

1.    To evolve integrated silkworm disease management strategies for the prevention/ control of silkworm diseases

2.    To act as a nodal centre for co-ordinating silkworm disease survey and surveillance programme in the eastern and north-eastern parts of India

3.    To extend R&D support to the sericulturists in the eastern and north-eastern parts of India

 

ACHIEVEMENTS:      

    LABEX a general silkworm bed-disinfectant, developed by this section, has been patented (Patent No. 200199) and commercialized.

    A room disinfectant, 5% Bleaching powder solution has been developed for the prevention of various silkworm diseases

    Developed a new general silkworm bed-disinfectant, SERICILLIN specifically for control of muscardine disease.

    Gattine disease is controlled by using 1% chlorine (bleaching powder solution) as room disinfectant and feeding of 700ppm Streptomycin sprayed leaves including dusting of Labex.

    Identified two botanicals for control of muscardine and grasserie diseases

     Elucidated the structure and nature of haemocytes of Bombyx mori L. and their role in the cellular defensive response.

    Identified disease tolerant silkworm races from the germplasm based on haemocyte immunity study

    Developed a simple agglutination test for early detection of BmNPV infection in B. mori L.

    An Agar Gel Double Diffusion Assay has been standardized for distinguishing the various serotypes of Bm NPV

    Identified hotspots for various disease occurrences in West Bengal and developed a forewarning calendar of silkworm disease incidence.

 

RESOURCES:

     Autoclave

     Centrifuge(REMI)

     Cyclomixer

     CO2 Incubator

     Leitz Diaplan compound microscope, Germany.

     Laminar Flow

     Water Purification System (Sartorius)

     Cell Sonicator

 

ONGOING PROJECTS / PILOT STUDY:

 

ARP3351: Studies on the morphology, life cycle and pathogenicity of some microsporidia infecting silkworm, Bombyx mori L. and their identification

 

Objectives:

a.    To study the biology of microsporidia

b.    To identify the virulent microsporidia based on their pathogenicity to Bombyx mori L.

c.     To investigate the impact of microsporidian infection on growth and development ofBombyx mori L.

d.    To identify the molecular markers for the identification of virulent and non-virulent microsporidia.

 
PILOT STUDY: Immunization of silkworm, Bombyx mori L. against bacterial disesase

 

Objectives:

a.    Immunization of disease tolerant silkworm breeds identified so far.

b.    The resultant protein rich compound / heat killed bacteria /other preferably low cost chemicals/botanicals suitable for immunization may be patented for the benefit of Sericulture industry.

 

 

CONCLUDED PROJECTS:

 

ARP3285:  Studies on the pathogens, pathogenesis and control of gattine in silkworm Bombyx mori L

 

Outcome:  It was found that Gattine disease is caused by an ultra virus and a bacterium (Staphylococcus vitulinus). Gattine disease is controlled by using 1% chlorine (bleaching powder solution) as room disinfectant and feeding of 700ppm Streptomycin including dusting of Labex as per recommendation, without affecting the economic characters of the cocoons.

 

ARP3286: Studies on the prevention and control of Nuclear Polyhedrosis and White Muscardine diseases of silkworm using botanicals

 

Outcome:  Identified an eco-friendly, effective and economically viable two botanicals for the prevention/ control of Grasserie and White Muscardine diseases of silkworm, Bombyx mori L.

 

Spray of 5% aqueous crude extract of PE-02 after every moult (30-45 m before resumption of feed) and 4th day of 5th instar is found to be very effective against White Muscardine

 

Spray of 7% aqueous crude extracts of PE-10 is used as a preventive/ control measure against  Grasserie disease by per oral administration through mulberry leaves after each moult (30-45 m  before resumption of feed) and on 4th day of 5th instar

 

ARP004: Studies on immunity and immunodiagnosis of silkworm diseases

 

Outcome:  A simple agglutination test has been developed for detection of BmNPV infection. An agar gel double diffusion assay has been standardized for distinguishing the various serotypes of BmNPV

 

ARP008: Haemocyte immunity study of silkworm, Bombyx mori L.

 

Outcome:  On the basis of cellular defense response to bacterial/ particulate virus infection, five multivoltine [Nistari, Debra, Nistari (DN)P, M6DP & M12(W)] and four bivoltine (SK3, SK6, BHR1 and BHR2) were identified as relatively tolerant from the germplasm

 

ARP002: Physiotherapeutic and chemotherapeutic studies towards control of silkworm diseases

 

 Outcome:  Recommended hot HCl treatment (1.05 sp. gravity at 46C for 30 m) for controlling pebrine at primary infection and Albendazole (0.5%) as feed to control pebrine at secondary infection. 

Nystatin (0.4%) was identified and recommended to control White Muscardine disease

 

ARP003: Studies on the improvement of disinfection

 

Labex, a silkworm bed-disinfectant and 5% Bleaching powder solution, an effective room disinfectant were formulated and recommended for the prevention of various silkworm diseases

 

 ARP005: Survey and surveillance of silkworm diseases and its management inWest Bengal

 

The pattern of incidence and hotspots for various silkworm diseases in commercial crop in West Bengal were identified