Goliath beetle characteristics, habitat, reproduction, nutrition

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David Holt

The Goliath beetle is the name given to the members of the genus Goliathus. It is an arthropod belonging to the Scarabaeidae family and is considered one of the largest beetles in the world. Its habitat is almost exclusively limited to the tropical forests of Africa.

The gender Goliathus It was first described by the famous Swedish naturalist Carlos Linnaeus in 1758. Since then a total of 5 species have been described.

Goliath beetle. Source: Drury, Dru, 1725-1803. Westwood, J. O. 1805-1893. / Public domain

Due to its large size, this beetle is one of the heaviest insects known to date. In addition, they tend to have solitary habits, they are only seen with another specimen during the mating period. Although its appearance can be a bit intimidating, it is a totally harmless animal.

Article index

  • 1 Characteristics of the Goliath beetle
  • 2 Morphology
    • 2.1 Head
    • 2.2 Thorax
    • 2.3 Abdomen
  • 3 Taxonomy
  • 4 Distribution and habitat
  • 5 Playback
    • 5.1 Courtship rituals
    • 5.2 Fertilization
    • 5.3 Ovoposition
    • 5.4 Larva
    • 5.5 Pupa
    • 5.6 Adult
  • 6 Nutrition
  • 7 References

Goliath beetle characteristics

The Goliath beetle is an animal classified as a multicellular eukaryote. This is so because the cells that comprise it have a structure known as the cell nucleus, within which the DNA is packaged to form the chromosomes. In addition, their cells are specialized in various functions.

Likewise, they are triblastic organisms, which means that during their embryonic development they present the three germ layers: mesoderm, endoderm and ectoderm. From them, the organs that will make up the adult organism are formed..

Their symmetry is bilateral, since they are made up of two exactly equal halves.

They reproduce in a sexual way, with internal fertilization and indirect development. They are oviparous because they reproduce through eggs.

Likewise, this beetle is mostly herbivorous, although the larvae can also feed on corpses in a state of decomposition..

Morphology

The Goliath beetle is one of the largest in the world. Its body is oval in shape. Males can measure up to 100 mm, while females are about 80 mm.

As with many arthropods, its body is segmented into three parts: head, thorax, and abdomen. They are dark in color (brown or black) and have some white spots, especially on the thorax.

Head

It is characterized by being totally independent of the thorax. Several appendages emerge from the head. First it has a pair of antennas. In the buccal region it has three pairs of oral appendages: the lips, the maxillae and the jaws. These are used by the insect during the feeding process.

In addition to this, on the head there are also the eyes, which are of the compound type.

The males have a Y-shaped horn. They use it in fights against rival males. Females lack that horn.

Chest

The thorax is divided into several segments. The three pairs of legs emerge from this part of the body. The distal coxa is known as tarsus and is shaped like a claw, which is used by this beetle to dig the hole and lay eggs, or to cling to the bark of trees..

Goliath Beetle specimen with outstretched wings. Source: Anagoria / CC BY (https://creativecommons.org/licenses/by/3.0)

A pair of wings also emerge from the thorax, which are quite thick and resistant, known as elytra. Their function is to protect the animal's body, apart from the obvious function of flying..

Abdomen

It is divided into eleven segments, approximately. Inside it houses the main viscera of the animal, which form the digestive, circulatory and respiratory systems.

Taxonomy

The taxonomic classification of the Goliath Beetle is as follows:

  • Domain: Eukarya
  • Animalia Kingdom
  • Phylum: Arthropoda
  • Class: Insecta
  • Order: Coleoptera
  • Family: Scarabaeidae
  • Subfamily: Cetoniinae
  • Gender: Goliathus

Distribution and habitat

The Goliath beetle is an animal that requires certain environmental conditions to survive. Among these we can mention: humidity of 40% - 60% and temperatures that are around 23 ° C to 36 ° C.

Taking this into account, the ecosystem in which this insect is found is in tropical forests. It is located mainly in the tropical forests of the African continent. As a curious fact, specialists have determined that in forests with equatorial rain the Goliath beetle species have reached the greatest diversity.

However, species can also be found in places with warmer temperatures, such as southeastern Africa..

Goliath beetle in its natural habitat. Source: H. Zell / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0)

Reproduction

The type of reproduction that is observed in this species of beetle is sexual. The essential characteristic of this type of reproduction is that it involves the fusion of female and male gametes (sex cells).

Courtship rituals

As with many species of animals, the Goliath beetle has a peculiar behavior when it comes to the mating process.

First of all, the males of this species of beetle are very territorial. This means that they establish a kind of perimeter, from which they expel the other males through fights that could be rivals and could compete for the females..

Females also play an important role in this courtship process, as they synthesize and release chemicals known as pheromones. These exert an attractive effect on individuals of the opposite sex.

In this sense, the females release pheromones, which are captured by the male. Later this allows the female to enter the territory previously demarcated by him to be able to start the mating process.

Fertilization

In the Goliath beetle, internal fertilization is appreciated, that is, inside the body of the female. For this to happen, a copulation process needs to take place.

Generally, the male beetle mounts on top of the female and inserts his copulatory organ into her in order to deposit the sperm. Once inside, the sperm fertilize the eggs and the female lays the eggs.

Oviposition

After fertilization, the female must find a good place to lay the eggs. This is how he proceeds to dig a hole in the ground to place the eggs there. These have an approximate development time of about 13 days.

Larva

When the development time has elapsed, the eggs hatch and a larva emerges from each one..

The Goliath beetle larvae are large in size, reaching a weight of up to 100 grams and about 2.5 cm in length. Many specialists claim that this is the main stage of this species of beetle. It can live as a larva for about 6 months, although cases have been seen in which it lives up to 1 year.

It is important to mention that the larva of the Goliath beetle is voraciously hungry, so it feeds on decomposing plant and animal matter almost constantly. This is so because it needs to obtain a large amount of energy so that it can become a pupa and later an adult..

Pupa

At a certain point, the larva builds a kind of cocoon that is known as the pupa. Inside, the larva will remain for a certain period of time, in which it develops its permanent structures..

Adult

Once the time in which the adult individual was formed has elapsed, it breaks the cocoon and it emerges.

The main function of the adult beetle is related to the reproduction process. Likewise, specialists have determined that the life span of an adult beetle is relatively short (a few weeks). This may be due to predators that use them for food. However, in captivity they can live up to 1 year..

Nutrition

The diet of the Goliath beetle, when it is in its adult form, is represented by substances that have a high sugar index. These include nectar from flowers, tree sap, and even pollen from certain plants. Due to this, it can be said that this beetle, at least in its adult stage, is herbivorous.

In this sense, it is important to emphasize that the diet depends on the habitat in which the beetle is found and on the availability of food. This is why there are also beetles that feed, among other things, on fruits and vegetables..

However, the larvae of the larval stage of this beetle also need to feed. However, their energy requirements are different from those of the adult, since they need high levels of protein. This is why the larvae feed on decomposing organic matter, so it can be said, without a doubt, that the larvae of the Goliath beetle are saprophagous..

References

  1. African Goliath Beetle. Retrieved from: https://britannica.com/animal/African-goliath-beetle
  2. Brusca, R. C. & Brusca, G. J., (2005). Invertebrates, 2nd edition. McGraw-Hill-Interamericana, Madrid
  3. Curtis, H., Barnes, S., Schneck, A. and Massarini, A. (2008). Biology. Editorial Médica Panamericana. 7th edition.
  4. Haines, D: (2019). 32 Goliath Beetle Facts: Ultimate Guide to All 5 Species. Retrieved from: https://everywherewild.com/goliath-beetle/
  5. Hickman, C. P., Roberts, L. S., Larson, A., Ober, W. C., & Garrison, C. (2001). Integrated principles of zoology (Vol. 15). McGraw-Hill.
  6. Lachaume, G. (1983) The Beetles of the World, volume 3, Goliathini 1. Sciences Nat, Venette

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