The Rhododendron and Azalea Bug. Rhododendron Lace Bug causes damage to leaves, causing them to roll downwards.
The leaves are normally mottled on the top surface, but seen to be brown on the underside. On the underside if the damaged leaf, you may find several of the Rhododendron Bugs.
The bug is normally no more than a few millimetres long with dark colourings. The lace pattern wings are a good camouflage and it may be difficult to see the bugs. The bugs and also their young - nymphs - have sharp mouth parts with which they pierce the leaf to suck the sap - causing the leaf damage and symptoms described above.
Because the bug and nymphs feed on the underside of the Rhododendron and Azalea leaves, the damage caused is not often found until considerable.
The adults insert their eggs into the leaf tissue of the Rhododendron, and covers them with a varnish-like splodge.
A natural predator of the Rhododendron Lace Bug, is the Lacewing. Please do not confuse, for the Lacewing - much larger and lime green - is a very beneficial insect in the garden. (Lacewing).
Chemical control might be necessary - especially in warm weather.
Imidacloprid - Provado (systemic) or Bifenthrin - (contact) can be used.
Imidacloprid can also be applied to the soil as a drench.