Capsid bug (Lygocoris pabulinus)
Despite giving plants a ragged appearance and, in severe cases, causing some die-back of leaves and deformation of fruit, this is rarely a serious disease. This is just as well as the bugs are often long gone by the time the damage is noticed, and they are quick-moving, dropping to the ground when disturbed - this makes control difficult. Adults are green and about 6mm long, with wings which make a distinctive diamond pattern when folded. The nymphs are wingless and paler in colour. Eggs hatch in April (2nd generation in early/midsummer). The nymphs feed on woody plants for a few weeks before moving on to surrounding herbaceous plants, pupating, emerging and laying more eggs on woody plants - it is as eggs that they overwinter. Like aphids, they suck the sap from the growing parts - shoot tips, buds, young leaves and flowers - of the plant. Unlike aphids, however, they inject a toxin which kills surrounding cells, leaving brown edges. As the leaves grow, these holes expand and tear.
- Small holes in young, growing parts of the plant, particularly young leaves
- As leaves expend, brown-edged holes which may tear
- Flowers and fruit may be deformed
Prevention & control
- Good crop hygiene, removing places to hide
- Keep weeds under control to encourage the bugs to move away to find food later in the season
- Encourage birds
- Check for the tiny holes from April onwards, picking off any that are found
- It is rarely a serious enough problem to require treating but, where damage is severe and persistent, insecticidal soap can be used when flowers first open and again when the fruit set.