Leafhopper populations are best monitored by visual inspection for the characteristic speckling damage which occurs initially on older leaves in the centre of the tree, and for the leafhoppers themselves which are often present on the undersides of damaged leaves.
- When populations are high, brushing the foliage or shaking the tree will cause large numbers of adults to leap from the tree and make a short flight before re-settling.
- In cool conditions, leafhopper populations can be estimated by beat sampling. However, in warm conditions most individuals simply fly away and do not fall into the beating tray.
- Another approach is to use yellow or white sticky traps.
- Economic thresholds have not been developed.
- However, damage is only likely to be significant if a large proportion of the leaf surface becomes bleached in mid or late summer.