Major pests of Tapioca are:-
1.Spiralling whitefly: Aleurodicus disperses
Symptoms of damage:
- Yellowing of leaves
- Sooty mould in lower leaves
- Dropping of affected leaves
Identification of pest:
- Eggs: Concentric rings covered with mealy coat
- Nymph: With numerous evenly spaced short glass-like rods of wax on the sides of the body
- Adult: Powdery white, active during early morning hours
Management:
- Remove the alternate host abutilon indicum from the field
- Place yellow sticky trap to attract whitefly.
2.Whitefly: Bemisia tabac
Symptoms of damage:
- Chlorotic spots on the leaves which latter coalesce forming irregular yellowing of leaf tissue
- Severe infestation results in premature defoliation
- Development of sooty mould
- Vector of cassava mosaic virus
Identification of pest:
- Nymph: Greenish yellow, oval in outline
- Adult: Minute insects with yellow body covered with a white waxy bloom
Management:
- Remove alternate host: Abutilon indicum
- Set up yellow sticky trap
- Spray any one of the following
- Phosalone 35 EC @2.5 l/ha
- Quinalphos 25 EC @ 2.0 l/ha
- Triazophos 40 EC 2.0 l/ha
3.Cassava scale: Aonidomytilus albus
Symptoms of damage:
- Infest stem portion
- Leaves of affected plants discoloured and dry up
- Stunting of plants
Identification of pest:
- Hard scale, oval and mussel like
Management:
- Selection of clean (scale-free) planting material)
- Destroy infested stems
- Encourage coccinellid predators
- Spray methyl demeton 0.25%.
4.Cassava Mealy bug: Paracoccus marginatus
Symptoms of damage:
- Sucking of sap at cassava shoot tips, on the lower surface of leaves, and on stems. During feeding it injects a toxin into the cassava plant
- Causing deformation of terminal shoots, which become stunted
- Resulting in compression of terminal leaves into “bunchy tops”
- Length of internodes is reduced, and stems are distorted
Identification of pest:
- Cassava Mealy bug is pinkish in colour
- Its body is surrounded by very short filaments, and covered with a fine coating of wax.
Management:
- Spray malathion or fenitrothion @1ml/ha
Source-
- TamilNadu Agritech Portal
