Capsid bugs

Capsid bugs spoil the appearance of plants by giving the foliage a tattered and distorted appearance and causing flower buds to abort.

Capsid damage on artichoke. Credit: RHS/Simon Garbutt.

Quick facts

Common name: Capsid bugs
Scientific name: Various species, mainly Lygocoris pabulinus and Lygus rugulipennis and apple capsid,  Plesiocoris rugicollis
Plants affected Many, including apples, beans, Caryopteris, Chrysanthemum, Clematis, Dahlia, Forsythia, Fuchsia, HydrangeaPhygelius, potatoes, roses and Salvia
Main symptoms: Leaves develop with many small holes. Flowers may be distorted or absent
Most active May-August

What are capsid bugs?

Capsid bugs are true bugs, there are many species. Most do not damage garden plants or are predatory. A few are sap-sucking pests that feed at the shoot tips, and on flower buds, of a wide range of herbaceous and woody plants. These include the common green capsid (Lygocoris pabulinus) and the tarnished or bishop bug (Lygus rugulipennis). Some pest capsid bugs have a more restricted host range such as the apple capsid (Plesiocoris rugicollis), which feeds on apple and pear. 

Symptoms

Signs of damage appear from late May to early September.
• As capsid bugs  feed, they damage and kill some of the cells where the mouthparts have probed
• The leaves near the shoot tips develop many small, brown-edged holes and may be misshapen
• Affected flower buds, particularly those of fuchsia, may fail to develop, or, in the case of chrysanthemum, dahlia and other daisy-like flowers, open unevenly
• Apple capsid (Plesiocoris rugicollis) damages the foliage and also feeds on the young fruitlets, which results in bumps or raised corky growths developing on the mature fruit. These blemishes are superficial and do not affect the eating and keeping qualities of the fruits. Apple capsid can also affect pear.

Control

Non-chemical

  • Apple cultivars vary in susceptibility to apple capsid – the fruits of Charles Ross’, ‘Allington Pippin’ and ‘Edward VII’ are some which may be extensively marked by capsid bumps.
  • If capsid bugs have been a problem in the past removing weeds which can act as alternative host plants can reduce the problem.
  • Removing dead vegetation in late winter may destroy overwintering sites for the tarnished plant bug.

Chemical control

  • Inspect the shoot tips of susceptible plants from mid-May onwards, treat with an insecticide if signs of damage are seen 
  • Ornamentals can be sprayed with thiacloprid (e.g. Bayer Provado Ultimate Bug Killer 2, Bayer Provado Ultimate Bug Killer Ready to Use), deltamethrin (e.g. Bayer Sprayday Greenfly Killer, Bayer Provado Ultimate Fruit & Vegetable Bug Killer) or  lambda-cyhalothrin (e.g. Westland Resolva Bug Killer)
  • Apples and pears can be sprayed with deltamethrin, lambda-cyhalothrin or the ready to use formulation of thiacloprid shortly after the flowers have fallen, provided the manufactures instructions are followed for this crop. 
  • Plants in flower should not be sprayed due to potential effects on pollinators
  • Vegetables generally tolerate capsid damage and do not need spraying for these pests.

Download

Pesticides for gardeners (Adobe Acrobat pdf document outlining pesticides available to gardeners)

Description and Biology

 

  • Adult capsid bugs are green or brown and up to 6mm long (¼in) Capsid bug wings are folded over the abdomen and have the basal two-thirds coloured and thickened, the outer third is translucent, which shows as a clear diamond-shaped area at the rear end of the insect.
  • Nymphs are wingless and generally pale green in colour 
  • Apple capsid overwinters as eggs that are laid in the bark of apple branches and shoots, these eggs hatch in April to May. They become adult in June and July and there is one generation a year.
  • Common green capsid overwinters as eggs inserted into a range of trees and shrubs. They eggs hatch in spring and become adults by July. These lay eggs and produce a second generation before the winter.
  • The tarnished plant bug overwinters as an adult in sheltered places. They emerge in spring and lay eggs on a wide range of plants. There are two generations a year.

Advertise here

We love free entry to our local RHS garden

Lucy, mum, part-time lectureer & RHS member

Become a member

Discuss this

for the site or to share your experiences on this topic and seek advice from our community of gardeners.