Leucauge behemoth

Leucauge behemoth
Female from Ecuador
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Order: Araneae
Infraorder: Araneomorphae
Family: Tetragnathidae
Genus: Leucauge
Species:
L. behemoth
Binomial name
Leucauge behemoth
Ferreira-Sousa, Venticinque, Motta & Brescovit, 2023

Leucauge behemoth is a species of orb-weaver spider in the family Tetragnathidae, formally described in 2023.[1][2] It is found in the Amazon rainforest of Brazil, Colombia, Ecuador, and Peru.[1][2] The species lives in colonies that are usually positioned above turbulent water.[2]

Description

Female from Ecuador

Leucauge behemoth is notable for its large size compared to other Neotropical species in the genus, with females measuring 8.8–11.9 mm in total length. The species has a distinctive coloration, with the anterior half of the abdomen covered in silver guanine patches and the posterior half black with two median parallel lines of guanine dots. Living specimens display a brownish-orange cephalic region, green thoracic region, and bright red book lung covers.[2]

Males can be distinguished from the closely related Leucauge argyra by their longer paracymbium and lack of a dorsobasal process on the palp. Females differ from L. argyra by having a rounded rather than conical ventral process on the epigynum, and unlike most Leucauge species, females lack an anterior hood on the epigynum.[2]

Distribution

L. behemoth has been recorded from the Amazon rainforest region across four South American countries. In Brazil, it has been found in the states of Amazonas, Acre, and Mato Grosso. The species also occurs in Colombia (Putumayo Department), Ecuador (Napo Province), and Peru (Loreto Region).[2]

Behavior

Leucauge behemoth is the first species in its genus for which complex colonial behavior with overlapping generations has been documented. Colonies typically contain 3–22 individuals of various ages and show vertical stratification, with spiders of different sizes occupying different heights within the colony. Small spiders under 2 mm do not build individual orb webs but live on the supporting threads of larger colony members' webs. Larger individuals build webs at different vertical levels, with the largest spiders (9–11 mm) occupying the intermediate and higher parts of colonies.[2]

The colonies are commonly found along stretches of streams with turbulent water, possibly because of increased availability of flying insect prey. When disturbed, colony members exhibit coordinated escape behavior, fleeing in groups to surrounding vegetation and returning after 10–20 minutes.[2]

Etymology

The specific name behemoth refers to the mythological beast Behemoth and alludes to the species' unusually large size compared with other members of Leucauge.[2]

References

  1. 1 2 World Spider Catalog (2026). "Leucauge behemoth Ferreira-Sousa, Venticinque, Motta & Brescovit, 2023". World Spider Catalog. Natural History Museum Bern. Retrieved 22 August 2026.
  2. 1 2 3 4 5 6 7 8 9 Ferreira-Sousa, Leonardo; Venticinque, Eduardo Martins; Motta, Paulo César; Brescovit, Antonio Domingos (8 December 2023). "The more, the merrier: a new colonial species of the orb weaving spider genus Leucauge White, 1841 (Araneae: Tetragnathidae) from the Amazon rainforest". Zootaxa. 5383 (1): 83–95. doi:10.11646/zootaxa.5383.1.7. PMID 38221258.