CERAMBYX PIG: CHARACTERISTICS, HABITAT, LIFE CYCLE, FEEDING - BIOLOGY - 2025

Cerambyx pig is a coleopteran insect that belongs to the Cerambycidae family and is found mainly on the European continent, although it can also be found in some countries in Asia and North Africa.

It was described for the first time by the Swedish zoologist Carlos Linneo in 1758. It is a species that has been sufficiently studied, for which reason it is considered by specialists as the “type species” of the genus Cerambyx.

Cerambyx Pig. Image by Kiki Miki from Pixabay.com

This insect is found inside the bark of the trees in which it lives. On occasion, Cerambyx pig larvae can cause terrible damage to the bark of young trees.

It has mainly nocturnal habits, so it is very rare to see it during daylight hours. It remains hidden in the tunnels it digs in the trunk of the trees, until nightfall. When it comes out of its den, it is mainly in search of a specimen of the opposite sex to reproduce.

It is considered a species that could be in danger of extinction, mainly due to the reduction of its natural habitats.

General characteristics

-Species: Cerambyx pig

Morphology

Cerambyx pig is a large insect, which, as with all arthropods, has a body segmented into several parts: head, thorax and abdomen.

Its body is long, reaching 7 cm in length. It is dark brown or black, although at the ends of the elytra it takes on a dark reddish color. It is important to note that the elytra are the fore wings that the animal has.

There is a certain sexual dimorphism in them. Males are larger than females, as well as having longer antennae as well.

The head is rough in appearance and has quite resistant and fearsome jaws that serve both to feed and to defend itself from any attack, mainly from individuals of the same species.

Also from the head a pair of antennae emerges, which are made up of eleven segments (artjos). In the case of males, the length of the antennae exceeds that of the animal's body, whereas in the female this does not occur.

Male and female Cerambyx pigs. Source: Cerambyx_cerdo_ (couple).jpg: Didier Descouensderivative work: B kimmel

They have three pairs of articulated legs, which have powerful hooks at their distal end that the animal can use for various functions, such as grasping the bark of trees or as support during the reproduction process.

Habitat and distribution

Worldwide, Cerambyx pig is a species that is found mainly in large regions of the European continent, as well as in Asia and a very small part of Africa.

In Europe it is possible to find it in almost all the countries that make it up. The exceptions are the Scandinavian countries (except Sweden), the Netherlands, Russia and the United Kingdom. Likewise, in Asia it is present in countries such as Turkey, Lebanon, Syria and Palestine, among others. In Africa it is limited only to small regions in the north of the continent.

Regarding the characteristics of its habitat, this insect has a predilection for the bark of trees in a state of decomposition. The type of trees in which it is found are those called "deciduous", such as elms, chestnut trees, birches and willows, among others.

In general, they are found in these trees when they are in forests located at low altitude. Cerambyx pig is particularly abundant in old forests, where the trees are long-lived and exceed 100 years.

Distribution of Cerambyx pig. Source: B kimmel

In addition, it prefers trees that, apart from being old, have a large diameter trunk (more than 50 cm).

Biological cycle

The type of reproduction that this insect has is sexual. This means that the union of the female gametes (ovules) with the male gametes (sperm) is required. Through this type of reproduction there is an exchange of genetic material.

In its biological cycle it is evident that this animal has a holometabolic development. This is defined as one in which the individual goes through several stages such as: embryo, larva, pupa and imago (adult).

It is important to note that individuals of this species can present one generation every three or four years. This means that this is the approximate duration of the biological cycle, from the beginning of the mating process between adults, until the new individual emerges ready to reproduce.

The biological cycle begins with the adult individual, which emerges from its development site to participate in the reproduction process. This occurs between the months of June and September (end).

Fertilization and egg laying

Once fertilization occurs between the male and the female, the latter proceeds to lay the eggs. Each female has the capacity to lay approximately more than 400 eggs.

The favorite place to put them is in the bark of large trees, such as cork oaks or holm oaks. The eggs have a shape that closely approximates a sphere and are of a characteristic ivory color, easy to identify. After a few days, the eggs hatch and the larvae emerge.

Larvae

This stage has an approximate duration of between 3 and 4 years. During all this time, the larvae feed on the wood from the bark of the trees.

As they feed, they dig galleries into the tree, sometimes reaching the xylem. It should be noted that the xylem is the conducting vessel through which water and minerals circulate.

The larvae can reach a length of 6 cm. During the entire larval stage, what the larva does is accumulate energy reserves and then be able to go through the transformation process to the next stage: the pupa.

Pupa

Once the larva has accumulated the necessary reserve quantity, it pupates. Before this, she excavates a gallery or tunnel that communicates with the outside of the plant. In this way, when the adult insect appears, it will have a way out to reproduce.

During this stage, the insect remains in apparent inactivity. It is in this state that the structures that will form the adult insect are formed and developed. At first, the pupae are light in color, but as time progresses, they darken until they reach the characteristic black color of the adult individual.

Adult insect

The adult insect appears approximately during the month of October. However, it does not leave the tree immediately, but instead waits until the following spring to do so.

In the following video you can see how two specimens mate:

Feeding

Cerambyx Pork is a heterotrophic organism, which means that it does not have the ability to synthesize its nutrients. Because of this, it must feed on other living beings or substances that they make. In this sense, this insect is classified as herbivore and within these it corresponds to the saproxylics.

Saproxylics are those organisms that feed exclusively on wood. In the case of Cerambyx pig, during its larval stage it feeds on the wood of the trunk in which it is housed.

At first the larvae feed on the bark, but as they develop, they begin to feed on the innermost parts of the trunk. For this, they are provided with a strong jaw that allows them to tear off pieces of wood.

When the insect is in the pupal stage, it does not feed, while when it reaches the adult stage, its food consists of the sap and juices exuded by the trees in which it lives.

Protected species

In some European countries such as Spain, Cerambyx pig is a species considered at risk of extinction. This is why in many countries it is even legally protected. For example, it is included in the Berne Convention (1979), where it is classified as a strictly protected species of fauna.

Likewise, in the IUCN red book it is classified as a vulnerable species, which means that it is in danger of becoming extinct in the medium or long term.

Taking this into account, in some places the use of any chemical product that may have as its main action the elimination of this insect is totally prohibited. Likewise, actions that may be aimed at controlling its population are prohibited.

However, this is not the case in all the places where it is found, since it has even come to be considered a pest that greatly affects trees that can still be considered young.

In this sense, the situation of Cerambyx pig is a bit ambiguous, since, although it is true that in a large number of countries it is seen as a protected species, it is also true that in others it is considered harmful to trees in those it inhabits and consequently, measures are applied for its eradication.

References

1. Brusca, RC & Brusca, GJ, (2005). Invertebrates, 2nd edition. McGraw-Hill-Interamericana, Madrid
2. Curtis, H., Barnes, S., Schneck, A. and Massarini, A. (2008). Biology. Editorial Médica Panamericana. 7th edition.
3. Government of Aragon. (2006). Quercus piercing longicorns. Cerambyx pig and Cerambyx welensii. Technical information.
4. Hernández, J. (1994). Biological cycle of some species of Cerambycidae under laboratory conditions (Coleoptera). Bulletin of the Spanish Society of Entomology. 18 (1)
5. Hickman, CP, Roberts, LS, Larson, A., Ober, WC, & Garrison, C. (2001). Integrated principles of zoology (Vol. 15). McGraw-Hill.
6. Pereira, J. (2014). Conservation plan for Cerambyx pig. Conservation biology.
7. Verdugo, A. (2004). The waxworms of Andalusia (Coleoptera: Cerambycidae). Andalusian Society of Entomology. Monograph n ° 1