Viburnum beetles are a species of leaf beetle that feast on shrubs from the viburnum family. The larvae (April to June) can be up to 8mm long, while the adult beetles (late July to September) are greyish brown in colour and around 4.5-6mm long.
The eggs hatch in the spring (around April or May) and the creamy yellow-coloured larvae, which have black markings, feed on the leaves for about a month before dropping to the soil.
Fully fed, they pupate in the soil, and when the adult beetles emerge in the summer, they return to the plant to continue feeding on the leaves and lay more eggs at the shoot tips. The eggs overwinter on the plant in the bark of the stems and then the cycle begins again in the spring.
Viburnum beetles are visible on infested plants in both of their growth stages. The damage starts as small holes in the leaves, and as they continue to feed, the lamina, or flesh of the leaf gets stripped away, leaving just the veins.
Leaves that are being eaten by viburnum beetles will have holes in them, while the large stem remains in tact. Ultimately, the leaves take on a lace-like appearance or are stripped away altogether.
Sometimes a viburnum beetle infestation can also be identified by a foul smell on the plant, which is thought to be caused by viburnum beetle larvae excrement.
These beetles feed exclusively on plants in the viburnum family, such as Viburnum tinus, V. opulus, V. lantana and others.
Here’s how to control a viburnum beetle infestation:
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