fungal diseases of Silkworm

1. Fungal Diseases of beneficial insects and
Their Management
Saleem Akhtar Baloch
ENT-724
Dept. of Entomology
PMAS-AAUR-Rawalpindi

2. Silk worm fungal diseases
Muscardines
• The muscardines are fungal diseases The
muscardine fungi produce asexual spores
(conidia) on the cuticle of cadavers, and
these conidia are the infective propagules.
• Depending on the pathogen species, these
conidia are white, green,yellow, black,
gray, or red, and the muscardine diseases
are named based on these colors.
• The most common muscardines are white
and green. (Mukesh and Chauhan 2017).

3. White Muscardine
• Causal organism:
• White muscardine is caused by
Beauveria bassiana
• Symptoms:
• The larvae loose appetite and become
inactive.
• Presence of moist specks on the skin.
• The larva vomits and turns flaccid.
• After death, larva gradually becomes
hard followed by mummification due to
growth of aerial mycelia and conidia
over the body and body turns chalky
white. (Fernando and Harry, 2012)

5. Green muscardine
• Causal organism:
• To insect Green muscardine is
caused by Nomuraea rileyi
• Symptoms:
• Larvae sluggish, with oil-
colored specks;
• Cadavers soft at first and then
stiffen, and finally covered with
bright green conidia
• Hemolymph Turbid. Gradually
full of beaded hyphal bodies or
hyphae (Fernando and Harry,
2012)

6. Black Muscardine
• Mycoses caused by M.
anisopliae are rare and
are called black
muscardine.
• Larvae killed by M.
anisopliae infections
turn dark green to black
• (Fernando and Harry,
2012)

7. Brown Muscardine /Aspergillosis
• Causal organism: Diseases caused by
Aspergillus spp. more than 10
Aspergillus species, mainly A. flavus,
A. ochraceus, A. oryzae, A.
parasiticus, and A. tamarii.
• Symptoms:
• Newly hatched larvae stop feeding,
stop moving, frequent vomiting, and
die in 2-3 days; late instars develop a
lesion, thorax protrudes, frequent
vomiting, die in 4-5 days; cadavers
stiff with hyphae penetrating
• Hemolymph Turbid. Hyphal bodies
not present

8. Gray muscardine
• Gray muscardine is also
mycoses caused by
filamentous fungi are
rare, but include Isaria
javanica(formerly
Paecilomyces avanicus)
(Huang et al., 2008),

9. Yellow muscardine
• Yellow muscardine caused by Isaria farinosa
(formerly P. farinosus),

10. Red Muscardine
• Red muscardine caused by Isaria
fumosoroseus (formerly P. fumosoroseus).

11. Grassy Muscardine
• Grassy muscardine is
caused by Hirsutella
necatrix,and
fusariosis is caused
by Fusarium species
(Jin, 2001). These
fungal pathogens
usually do not pose a
threat to sericulture.

12. Microsporidia
Pebrine
Casual organism:
• Pebrine is caused by various
microsporidia, predominantly Nosema
bombycis and, to a lesser extent,
Vairimorpha, Pleistophora, and
Thelohania species.
Symptoms:
• Growth slow and typically
asynchronous, molting may be
incomplete; no cocoon formation;
spores present in the hemolymph,
midgut, silk gland, feces and eggs;
ovoid 2.9-4.1 x 1.5-2.1 mm

13. Disease management
• Management:
• Disinfect the rearing house, surroundings and with
recommended disinfectant as mentioned above.
• Conduct strict mother moth examination and surface
disinfection of silkworm eggs to produce and rear disease
free layings.
• Follow strict hygiene maintenance during rearing.
• Control mulberry pests in and around the mulberry garden.
• Apply recommended bed disinfectant, Vijetha/Ankush as
per schedule and quantity.
• Monitor seed crops constantly to eliminate the
microspodian infection.

14. • Apply Dithane M45 (3 kg/100 ) / Vijetha
supplement as disinfectant on the larvae
• Disinfect rearing rooms and trays with 4 per
cent pentachlorophenol to control
Aspergillosis.
• Talcum ,Lime , Paraformaldehyde, Ceresan
(phenylmercuric acetate) , Chlorinated lime ,
Sorbic acid ,Salicylic acid, Maneb ,Zineb .
Mancozeb, Cufram Z (octabithio carbamate)
(Kiyoshi Kawakami, 1982)

15. Refrences
• Fernando E. Vega, Harry K. Kaya (Eds.) - Insect Pathology Academic
Press (2012)
• Tayal, Mukesh K., and T. P. S. Chauhan. "Silkworm diseases and
pests." Industrial entomology (2017): 265-289.Springer Nature
Singapore Pte Ltd.
• Kiyoshi Kawakami, 1982. Causal Pathogens of Aspergillus Disease of
Silkworm and Its Control. Japan Agricultural Research Quarterly.
185-190
• Nguyen, Mau Tuan, et al. "Taxonomic characteristics of six species
of entomopathogenic fungi isolated from the silkworm, Bombyx
mori." International Journal of Industrial Entomology 9.2 (2004):
229-234.
• Guo-Ping, Kang, and Guo Xi-Jie. "Overview of silkworm pathology in
China." African Journal of Biotechnology 10.79 (2011): 18046-
18056.

16. Thanks