Pests of Silkworm

Uzifly (Exorista soebillans)

• Type of Damage: Reduces cocoon yield and quality, causes death of larvae.
• Symptoms: White eggs on larval skin, black scars, larvae die before spinning, pierced cocoons.
• Occurrence: Throughout the year, more severe in winter.
• Management: Maintain hygiene in rearing rooms. Use wire mesh on doors/windows. Spray 1% benzoic acid on larvae. Use uzicide tablets in water to attract adults. Release parasitoid Nesolynx thymus to control population.

• Beetles (Dermestes cadaverinus) Type of Damage: Adults and larvae feed on stored cocoons and pupae. Symptoms: Damaged cocoons, eaten pupa, and silkworm eggs. Management: Fumigate storage rooms with methyl bromide occasionally.
• Ants Type of Damage: Attack silkworms in rearing trays. Management: Apply ash or kerosene at mountage handles to deter ants.

Diseases of Silkworm

• Viral Diseases Grasserie: Swollen larvae, milky fluid oozes on injury, larvae don’t moult. Flacherie: Lethargic larvae, vomiting, dysentery, foul-smelling dead larvae. Management: Sun-drying appliances, bleaching powder disinfection, early diagnosis, feed nutritious mulberry leaves.
• Bacterial Diseases Symptoms: Stunted growth, lethargy, vomiting, dysentery, foul smell. Management: Maintain hygiene, avoid overcrowding, use antibiotics (Streptomycin/Tetracycline).
• Fungal Diseases (Muscardine) Types: White Muscardine (Beauveria bassiana), Green Muscardine (Spicaria prasina), Aspergillosis (Aspergillus species) Symptoms: Lethargy, hardened mummified larvae with white/green mold. Management: Keep rearing room dry, disinfect with bleaching powder, use Dithane M45 or Vijetha.
• Protozoan Disease (Pebrine) Symptoms: Slow growth, undersized body, pale and flaccid larvae, black spots. Management: Produce healthy eggs, disinfect rearing rooms, maintain hygiene, disinfect eggs with 2% formalin before incubation.