The name cardinal beetle typically refers to three different species of
beetle
Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...
s. The red-headed or 'common' cardinal beetle (''
Pyrochroa serraticornis'') is a red to orange beetle with, as the name suggests, a red head. It is about long, and is found throughout Britain. The rarer black-headed cardinal beetle (''P. coccinea''), similarly found at sites across Britain, is larger and a deeper blood red. The scarce cardinal beetle (''
Schizotus pectinicornis
''Schizotus'' is a genus of fire-colored beetles in the family Pyrochroidae. There are at least three described species in ''Schizotus''.
Species
These three species belong to the genus ''Schizotus'':
* ''Schizotus cervicalis'' Newman, 1838
* '' ...
'') also has a black head, but is smaller at around long. The scarce cardinal is only found at a few sites in Scotland and Wales.

Cardinal beetles
prey
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...
on other
insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs ...
s, while their bright red colour prevents them being the target of other
predator
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill ...
s which believe them to be
toxic
Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subs ...
.
Habitat
Red-headed cardinal beetles are normally found at the edges of
woodland
A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the '' plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunlight and limited shade (see ...
. Adults of this variety usually emerge around May in England, when they tend to be found under loose bark on deciduous trees. Fallen and standing timber and rotting stumps may also host this species. As the weather gets warmer, they disperse and are often found on dense, low herbage.
They bask for long periods on large leaves often near water – the
Grand Union Canal
The Grand Union Canal in England is part of the British canal system. It is the principal navigable waterway between London and the Midlands. Starting in London, one arm runs to Leicester and another ends in Birmingham, with the latter s ...
being one particular hotspot.
Identification
People often mistake the smaller
scarlet lily beetle
The scarlet lily beetle, red lily beetle, or lily leaf beetle (''Lilioceris lilii''), is a leaf beetle that eats the leaves, stem, buds, and flowers, of lilies, fritillaries and other members of the family Liliaceae. It lays its eggs most often ...
, ''Lilioceris lilii'', for a cardinal beetle as they also have a black underside and wings that are spotless and red. However, the scarlet lily leaf beetle's wing cases have tiny dimples and are shinier and more rounded than the dull, narrow, flattened and elongated cardinal beetle. The beetles can also be distinguished by the cardinal's toothed antennae. Another difference between the two is their diets. Scarlet lily leaf beetles are
herbivores
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpar ...
and are usually found eating lily leaves, whereas cardinal beetles are usually found on tree bark and flowers and feed on flying insects.
References
{{Taxonbar, from=Q179827
Tenebrionoidea
Articles containing video clips
Beetles described in 1762
Taxa named by Carl Linnaeus
Insect common names