Pest insects in carrot and Apiaceous crops: mirid bugs (capsids)

Mirid bugs feed on the shoots and stems of celery plants. Discover ways of monitoring pest populations and bringing down infestation. 

Orthops campestris (part of the Miridae family) is the main species causing damage. It overwinters as an adult and completes its life cycle on Apiaceous weeds, such as wild parsnip and wild carrot. In 2015, where monitoring started in January, adults became more active in mid-April, and the first nymphs were found in mid-May. It seems unlikely that this species completes just a single generation in the UK. The data from 2015 suggest there are two generations.

Adult and nymph bugs feed on the stems and shoots of celery plants, causing distortion and damage.

There are two ways to monitor mirid bug populations: 

• Adults and nymphs infesting Apiaceous weeds can be sampled by beating the foliage onto a tray 
• Adults can be captured on the sticky traps used to monitor carrot fly 

These techniques will give you an idea of how large your infestation is. 

As Orthops campestris completes its life cycle on Apiaceous weeds, reducing the presence of these weeds near your crops may bring down your infestation levels. 

For organic crops, you can use mesh covers to protect plants. These work well if applied at the right time, as long as they are well sealed. The downside of using covers is that they can make diseases such as celery late blight (Septoria apiicola) worse, reducing crop quality. 

If you would like to order a hard copy of the Carrot & Parsnip Crop Walkers' Guide, please contact publications@ahdb.org.uk or call 0247 799 0069.

Content for this web page was originally authored by Rosemary Collier, University of Warwick.