About the Red Headed Cardinal Beetle - Facts & Information

The Red Headed Cardinal beetle is a medium sized beetle found across the UK.

What do They Look Like?

Adults are mid sized, with a bright red head and wing case (hence their name!). They also have black legs and antennae. However, when they are in the larval stage, they are more of a yellow brown color with dark heads.

It's easy to confuse this bright red beetle with the Black Headed Cardinal Beetle (pyrochroa coccinea), the Scarce Cardinal Beetle and lily beetle, the lily beetle has a much more rounded body and are covered in dimples on their wing cases.

Their Diet

Depending on what stage they are at in their lives, these beetles eat different diets. As larvae, they mainly live off of eating other insects larvae, hunting and living in damp, rotting wood.

 

Once they become adults, their diets change to mainly be nectar and pollen from flowers like cow parsley and hawthorn. They will also eat other species of insects too.

They are helpful to the environment, and our gardens, as they help get rid of small pesty insects.

Where do They Live?

The Red Headed Cardinal Beetle thrives in a few sites, including woodland edges, where tree trunks, fallen logs and dead wood are the perfect place for larvae to grow.

Resting upon leaves and flowers, hedgerows and riverbanks are also a popular spot for this insect.

Breeding

Similar to other insects, these beetles follow a egg - larva - pupa - adult life cycle. To start with, they breed in late spring to early summer, with males using their toothed antennae to detect females. Females lay eggs within rotting wood or under loose bark.

Larvae

The larvae are a predatory species, and live in moist, rotting wood, feeding on other insects larvae. This stage lasts around a year before the creature pupates.

Pupal

In the early spring, Red Headed Cardinal Beetle larvae pupate inside the wood, and after a few weeks, they emerge as fully fledged adults!

Adult

Only lasting a few months, adults spend their lives feeding on nectar, polled and small insects. Their bright red colour warns potential predators they are toxic, so they stay pretty safe for their lifetime.

The cycle then continues, with the next generation emerging at the same time, the following year.

Five Fun Facts

1. Its vivid red colour warns predators that it is toxic or foul-tasting, a defense called aposematism.

2. Males have serrated antennae, which help them detect females by picking up pheromones in the air.

3. While adults mostly eat nectar, the larvae are fierce predators, hunting other insect larvae in decaying wood!

4. These beetles can fly quickly, using their flexible wing covers to escape danger.

5. Cardinal beetles belong to the Pyrochroidae family, which has existed for millions of years, dating back to the time of the dinosaurs!