Pests and diseases frequently asked questions

A customer recently brought in a leaf for to ask if we knew what was the cause.


My viburnum has holes eaten in the leaves, with the larger leaf veins remaining, giving the foliage a lace-doily appearance?


Chris replies:


A late hit from beetles!


It appears the Viburnum beetle is making its presence felt again this late into the season with a number of customers reporting some nasty incidents. Typically, holes are eaten in the leaves, with the larger leaf veins remaining, giving the foliage a lace-doily appearance. This photo was from a relatively new plant established just last year. You may even spot the greyish brown adult beetles, 4.5-6mm long, feed on the leaves from late July to September. As for control, spray the plants with deltamethrin (Bayer Sprayday Greenfly Killer) or thiacloprid (Bayer Provado Ultimate Bug Killer). Organic gardeners can opt for pyrethrum (e.g. Py Spray Garden Insect Killer, Doff All in One Bug Spray, Scotts Bug Clear Gun for Fruit & Veg). Pyrethrum should control newly hatched larvae but will be less successful against the adult beetles. Please bear in mind that Viburnum beetle looks unsightly but plants affected normally recover as they re-flush into new growth in the spring.