- Nymphs and adults are seen in colonies on the lower surface of leaves.
- Due to drraining of sap by the insect numerous pin point spots develop on both surface of leaves and the areas where the insects colonize turn yellowish in colour(Fig 116).
- The symptom of damage is visible from a distance.
Select 10 plants per cent at random and assess intensity of damage as mild ,moderate and severe. Also note the presence of adults and nymphs.
Mild : Yellowing of one outer whorl of leaf associated with the presence of the pest or its feeding punctures.
Moderate: Premature withering of more than one outer whorl of leaves associated with feeding punctures or presence of pests.
Severe: Withering of all outer whorl of leaves followed by yellowing of one inner whorl of leaf associated with feeding punctures or presence of pest.
Mild-Yellowing of one outer whorl of leaf associated with presence of pest or its feeding punctures.