This pest appears to be on the increase in situations where it has previously not been found, and hot dry summers are the cause.
This is demonstrated by many tiny scratchings on the leaf.
One possible solution is to grow box hedges and topiary in the shade (resulting in an attractive glaucous leaf colour).
This is not always possible and, where the problem occurs, the Royal Horticultural Society suggests 2 or 3 applications of Bifenthrin at fortnightly intervals. This is obtainable as follows:
||Sybol Extra Polysect
|P B I
||Bio Sprayday Greenfly Killer plus
||Bug - Free
|Other insecticides are available: Check labels.
Spray in April/May then feed the plants for a quick re-flush of fresh leaf.
Red spider mite species are not unique to box and it is thought unlikely that box will be uniquely attacked should hotter summers become the norm.
The garden could become host to many pathogens not yet prolific and it is EBTS policy to recommend that good cultural practices be observed to promote the general health and well being of all species of plant.
We leave the recommendation of chemical controls to others in the field of plant pathology.