We use some essential cookies to make this website work.
We’d like to set additional cookies to understand how you use forestresearch.gov.uk, remember your settings and improve our services.
Preparing to search
Carcelia iliaca (C. iliaca) is a parasitoid that is associated with Oak Processionary Moth (Thaumetopoea processionea; OPM).
C. iliaca parasitises older, almost full-grown OPM larvae inside or outside OPM nests and then completes its development by overwintering in a spent OPM nest before emerging the following spring.
Where C. iliaca is observed on OPM nests, caterpillars may appear agitated.
Bottom picture: credit The Royal Parks
To request a pdf (non-accessible) version of this field guide, please contact the OPM team.
Cookies are files saved on your phone, tablet or computer when you visit a website.
Find out more about cookies on forestresearch.gov.uk
We use 3 types of cookie. You can choose which cookies you're happy for us to use.
These essential cookies do things like remember your progress through a form. They always need to be on.
We use Google Analytics to measure how you use the website so we can improve it based on user needs. Google Analytics sets cookies that store anonymised information about: how you got to the site the pages you visit on forestresearch.gov.uk and how long you spend on each page what you click on while you're visiting the site
Some forestresearch.gov.uk pages may contain content from other sites, like YouTube or Flickr, which may set their own cookies. These sites are sometimes called ‘third party’ services. This tells us how many people are seeing the content and whether it’s useful.