Summer pest guide

Make sure your plants don't succumb to the ravages of the summer pests.

Blackfly
These aphids are not so much of a problem now on broad beans but they infest elders, philadelphus and other shrubs in great colonies, often attended by ants which milk them then carry them to pastures new. Squash them, spray them, leave the ladybirds to sort them out or cut off the affected shoots.

Leaf miner
These grubs live between the upper and lower surface of the leaf and tunnel their way through leaves. Irregular, pale lines show where they have been and you can often see the grub at one end of the trail. Damage is usually not harmful, just cosmetic. Squash the grubs or spray with a systemic insecticide.

Leafhoppers
Though you may not see them, you will notice the damage caused by these small, pale green insects. Leaves develop light green spots, sometimes so many that leaves appear mottled. Primulas are favourite plants but many others are attacked. In most cases, damage is light but otherwise spray with a systemic insecticide.

Viburnum beetle
This small beetle eats the foliage of many viburnums, especially V. tinus and V. opulus, reducing the leaves to a network of veins. Often the smell of the beetle frass (droppings) is obvious too. Trim off the worst damage and/or spray with a systemic insecticide.