Capsid Bugs

Tattered leaves, distorted flowers, and corky fruit may indicate capsid bugs.

Nettle capsid bug and leaf damage (Line Sabroe) CC BY 2.0

Capsid bug identification

There are several capsid bug species, but they all have one thing in common: a triangle on their back. Capsid bugs can be green or brown and up to ¼” long. They fold their wings over the abdomen. The 2/3 of the wings closest to the body are darker and thicker-looking. The outer third is translucent, showing a diamond-shaped area on the insect’s rear end. Nymphs are pale green and wingless.

Some of the more common capsid bug species include:

• apple capsid (Plesiocoris rugicollis)–feeds on apple and pear
• African capsid (Bryocoropsis laticollis)
• common green capsid bug (Lygocoris pabulinus)
• delicate apple capsid (Malacocoris chlorizans)
• green tobacco capsid (Nesidiocoris tenuis)
• Mirid bug (Deraeocoris ruber)—European predator
• nettle capsid (Liocoris tripustulatus)
• tarnished or bishop bug (Lygus rugulipennis)—cousin to Lygus bugs

European predatory capsid (Nikk) CC BY 2.0

Capsid bug hosts

Capsid bugs feed on many different flowers, including butterfly bush, chrysanthemums, clematis, dahlia, fuchsia, hydrangea, roses, and salvia. They can also be found on apples, beans, and pears. Some capsid bugs are predators.

Capsid bug damage

Early capsid bug damage is easy to overlook. What starts as several small leaf holes can transform into something that looks like gale force shredding. Leaves growing near shoot tips may also be misshapen with several small, brown-edged holes. Flowers often become distorted. Apples and pears develop corky growths where capsid bugs fed on them during their early development. These bits can be cut off. The rest of the fruit is fine.

Green tobacco capsid (Merle Shepard, et al, Insects and their Natural Enemies…, Bugwood.org) CC BY 3.0 US

Capsid bug lifecycle

Capsid bugs are true bugs, which means they have mouthparts designed for piercing and sucking. These pests are active in late spring through summer. They lay their eggs in the bark of twigs and branches. Those eggs hatch in spring. Except for the tarnish bug, which overwinters as an adult. Depending on the species, there can be one or two generations each year.

Delicate apple capsid (Mick Talbot) CC BY 2.0

Capsid bug management

Minor capsid bug infestations can be ignored. The threat of capsid bug feeding can be reduced by planting resistant cultivars. Capsid bug management starts with monitoring susceptible plants, starting in spring, and removing weeds from around those plants. At the end of the growing season, remove plant debris from around these plants, as well. This eliminates hiding and overwintering places for capsid bugs.

Birds and ground beetles eat capsid bugs, so making the garden safe and appealing for them will help. Severe infestations can be treated with summer oils, neem oil, or pyrethrum [not pyrethroids].