ARACHNOLOGY: HISTORY, FIELD OF STUDY AND APPLICATIONS - BIOLOGY - 2025

The aracnología is a branch of zoology devoted to the study of spiders, scorpions, mites and other related agencies known as arachnids. These arthropods are characterized by presenting four pairs of legs, an oral apparatus with a pair of structures known as chelicerae, a pair of pedipalps, and the body divided into cephalothorax and abdomen.

Unlike other arthropods such as insects and crustaceans, arachnids do not have antennae. The word arachnology comes from the Greek: αραχνη, arachne, "spider"; and λόγος, logos, "knowledge."

Diversity of spiders. Source: Ernst Haeckel

More than 100,000 species of arachnids are currently known, being the second most diverse group of arthropods, after insects. They are a cosmopolitan group, present in a large number of ecosystems around the planet.

History

The first descriptions of arachnids using binomial nomenclature were made by the Swedish naturalist Carl Alexander Clerck (1709-1765), about 250 years ago. Clerk is considered the first arachnologist in the scientific world.

In its beginnings, the knowledge of arachnids was approached by entomologists, which is why some mistakenly consider arachnology as a branch of entomology.

The Linneus Naturae System includes 29 species of the genus Acarus. Between the 19th and 20th centuries, the works of the acarologists Kramer, Canestrini, Berlesse, Doreste, among others, stand out. In 1971 the Acarological Society of America was created, which brought together acarologists from all American countries.

Advances in optical instrument technologies during the 19th century allowed the development of important morphological studies, which in turn served to broaden the knowledge of the systematics and biogeography of arachnids.

As in other biological groups, molecular techniques have contributed substantially to the increase in knowledge of the phylogenetic relationships of arachnids. This has allowed the construction of classifications that seek to reflect the evolutionary history of this group.

The XIX International Congress of Arachnology, held in Taiwan in June 2013, was a scientific meeting of arachnologists where the use of molecular techniques was highlighted.

Spiders in mythology

Arachnology as a branch of science, has an important background in the knowledge and beliefs about arachnids that many cultures in the world had.

The two groups of arachnids most represented in the mythological symbols of different cultures are spiders and scorpions. Thus, we find Tarantism in southern Italy, as an expression of medieval European traditions related to the spider.

In ancient Egypt, as in Babylon, spiders were associated with the action of spinning and weaving destinies, linking them to the goddesses Neith and Ishtar respectively. In Greek culture they were linked to the goddess Athena.

Aerial view of the «Spider», one of the best known geoglyphs of the Nazca Lines, located in the Sechura Desert in southern Peru. Source: Diego Delso

Among the famous geoglyphs, known as Nazca Lines, built by the Nazca culture of Peru, an enormous spider is enigmatically represented. While in North America we find the myth of the spider woman.

In the cultures of the islands of the Pacific Ocean, the spider is involved as a creative divinity. In Melanesia, the spider has a symbolism of a deceiver, under the name of Marawa.

Among the Mayans, the scorpion represents the god of hunting and is identified with one of the constellations. This agrees with the interpretations of the first constellations by the Babylonian astronomers.

What does arachnology study? Field of study

Taxonomic study groups

The organisms studied by arachnologists include fourteen orders: spiders, ricinuleids, ppilions, scorpions, pseudoscorpions, mites, solifuges, amblipigids, uropigids, palpigrades, schizomids, haptopods, phalangiotarbids, and trigonotarbids.

Spiders are a very large group of predatory species, capable of weaving webs. They present chelicerae in the shape of a needle, which serves to inoculate their prey with poison. They present great diversity in size, shapes and colors.

Platycryptus undatus female. Source: Kevincollins123, from Wikimedia Commons.

Riciuuleids

Ricinuleids are small, spider-like arachnids with pincer-ending chelicerae. They lack eyes.

Opiliones

The opiliones are known as patone spiders because of their limbs. They are distinguished from spiders by not presenting a narrowing between the prosome and the metasoma.

Scorpions

Scorpions are characterized by their pincer-terminated pedipalps, and their long-tail-shaped metasoma, ending in a stinger with poisonous glands.

Pseudoscorpions

Pseudoscorpions are similar to scorpions. Although they have pincer-terminated pedipalps, they lack a stinger-terminated opistosome.

Mites

Mites are the most diverse group in terms of shapes and habitats. Includes terrestrial and aquaculture, parasite or free-living species. Among them are grouped ticks and numerous families of phytophagous mites, parasites in humans and animals, and many free-living species.

Solifugos

The solifugos have highly developed chelicerae and a visibly segmented abdomen.

Amblipidid

Amblipigids are known as cave spiders. Its large pedipalps stand out with numerous spines along its first pair of legs.

Uropigids

The uropigids have large and robust pedipalps, and have a multi-articulated flagellum at the leather end. They also have anal glands that produce an irritating liquid with the smell of vinegar.

Palpigrades and Schizomids

Palpigrades and schizomids are very small arachnids (less than 8 mm). They live on the ground, in litter and under stones.

Haptopods, phalangiotarbids and trigonotarbids

The haptopods, phalangiotarbids, and trigonotarbids are extinct species. Trigonotarbids are the oldest arachnids on the planet.

Basic, applied and cultural arachnology

The field of study of arachnology ranges from basic studies of arachnids (systematics, ecology and biology.), To studies applied to different disciplines among which medicine and agriculture stand out.

Some use the term cultural arachnology or ethnoaracnology to refer to the study of arachnids in cultural, religious and artistic expressions in different cultures.

Applications

Arachnological studies have applications in different areas.

In agriculture they allow us to assess the impact of many pests on crops. Also know the ecology and ethology of predatory species, such as spiders and predatory mites, which can be used as biological controllers.

In human and medical-veterinary medicine, arachnological studies make it possible to evaluate the species that behave like parasites, such as scabies or the numerous species of ticks that attack humans and domestic animals.

Studies of spider and scorpion venoms are useful in producing drugs that neutralize the action of toxins. In addition, they allow us to find useful biomolecules for the cure and treatment of many diseases, Some species of spiders are used as food by indigenous communities in South America.

References

1. Arachnology. (2019, January 23). Wikipedia, The Free Encyclopedia. Consultation date: 10:17, February 1, 2019.
2. (2019, January 30). In Wikipedia, The Free Encyclopedia. Retrieved 10:22, February 1, 2019.
3. Giribet, G and Austin, A. (2014). Arachnology in space and time: novel research on arachnid systematics and biogeography. Invertebrate Systematics 28i:
4. Lian, W. et al. 2018. The venom of spider Haplopelma hainanum suppresses proliferation and induces apoptosis in hepatic cancer cells by caspase activation in vitro. Journal of Ethnopharmacology 225: 169-177
5. Mammola et al. (2017), Record breaking achievements by spiders and the scientists who study them. PeerJ 5: e3972; DOI 10.7717 / peerj.3972
6. Melic A (2002): From Spider Mother to Scorpion Demon:

   Arachnids in Mythology ARACNET 10 - Iberian Journal of Arachnology (Boletín), 5: 112–124.

7. Opatova, V. et al. (2019). Phylogenetic systematics and evolution of the spider infraorder Mygalomorphae using genomic scale data. Biorsiv.
8. Savory, TH (1928). The biology of spiders. Cambridge. London. 376pp.
9. Sandidge, JS (2003). Scavenging by brown recluse spiders. Nature 426: 30.
10. Sato et al. (2019). Phylogeography of lethal male fighting in a social spider mite. Ecology and evolution 2019: 1-13.