Insect Pests of Fruit, Plantation, Medicinal & Aromatic Crops (2+1)

6. Cottony cushion scale

6.Cottony cushion scale - Icerya purchasi Maskell. ( Margarodidae : Hemiptera)

Damage

• Both nymphs and adults infest the twigs and leaves.
• The infested twigs are killed and leaves turned pale and dropped prematurely.
• The development of sooty mould on the infested leaves is typical symptom.
Bionomics

• It reproduces parthenogenetically as the males are rare.
• The female scale lays up to 700 eggs in the ovisac held behind the body.
• The newly hatched out nymphs feeds on leaves and twigs.
• It becomes adult after moulting for three times.
• The life cycle is completed in 46-240 days.
Management

• Collect damaged twigs and stems along with soft and hard scales and destroy.
• Spray methyl parathion 0.03% emulsion or dimethoate + kerosene oil at 150 ml + 250 ml respectively in 100 1 of water or carbaryl 0.05% + oil 1% or malathion 0.1% or monocrotophos 1 ml/ 1 or fenthion 100 EC 1 ml/l.
• Spray fish oil rosin soap 25 g/1 or neem oil 3% or dimethoate 0.03 % /1.
• Encourage natural enemies, Aphelinus sp., and predators, Chilocorus nigritus, Scymnus sp. and Rodolia cardinalis.
• Enforce ban by law, transport of wattle from the Nilgiris and kodaikanal to elsewhere.