Azilia Keyserling 1881
Creators: name: Álvarez-Padilla, Fernando
name: Hormiga, Gustavo
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Apiales
Apiaceae
Azilia

description: AZILIA KEYSERLING, 1881 (FIGS 2B, 3C, 13–17)   
 Type species: Azilia formosa Keyserling, 1881a. According to Levi (1980) the type specimens of A. formosa are from Peru and were deposited at the Polish Academy of Sciences, but are presumed to be lost. There are no indications in either Keyserling or Levi’s studies of the number of syntypes.   
 Diagnosis: Azilia species can be distinguished from all other tetragnathid genera by the following combination of characters: all eyes without tapeta, the rhabdome arranged in rows that form loops (Levi, 1980: figs 299, 300); lateral eyes of both sexes separated (i.e. not juxtaposed), more than one PLE diameter apart (Figs 2B, 14A, B); male pedipalp without conductor (Fig. 16A–F); epigynum flat (Fig. 15A, B); spermathecae walls weakly sclerotized (Figs 15C, D, 17B); and absence of femoral trichobothria (Fig. 14G, H).   
 Description: Female: body length from 6.9 to 9.9 mm. Carapace thoracic and cephalic regions at the same height, cephalothorax ocular area slightly lower than the carapace lateral margins and cephalic fovea formed by two longitudinal pits (Fig. 14A, B). Clypeus height less than one AME diameter. Anterior surface of chelicerae smooth (Fig. 14C). Cheliceral boss present. Sternum longer than wide. Labium trapezoidal and rebordered. Endites rebordered, longer than wide (Fig. 14E). Abdomen oval, sometimes with a hump above the spinnerets (Levi, 1980: fig. 297). Booklung covers smooth. Median tracheae undivided and longer than half the lateral tracheae length (Fig. 13A), leaf-shaped apically (Fig. 13D). Tracheal spiracle near the spinnerets, with more than four accessory glands on each side (Fig. 13B, C). ALS with more than 60 piriform spigots. PMS anterior surface with c. 32 aciniform spigots. PLS cylindrical spigots near spinneret margins, with c. 40 aciniform spigots and aggregate spigots on the distal margin separated from the flagelliform spigot apex (Fig. 13F, G). Epigynum flat, copulatory openings as two pits posteriorly orientated (Fig. 15A, B). Spermathecal walls weakly sclerotized, accessory gland openings arranged in groups (Figs 15F, G, 17B). Fertilization and copulatory ducts shorter than half the spermathecae length, coiled (Figs 15E, 17B).   
 Male: body length from 5.2 to 6.9 mm. Somatic morphology as in female. PLS triplet reduced to nubbins. Epiandrous fusules immersed in pits, arranged in a transversal line of many clusters and over a flat sclerotized plate (Fig. 13H). Male palpal patella with one macroseta, tibia from two to more than four times longer than wide (A. marmorata; Mello-Leitão, 1948: fig. 7); tibial ectal surface with trichobothria (Fig. 16D). Paracymbium shorter than half the cymbium length, covered with macrosetae, and its attachment to the cymbium well sclerotized (Fig. 16D). Conductor absent. Sperm duct coiled (Fig. 17A). Embolus lamelliform, curving less than one turn (Figs 16F, 17C).   
 Natural history: Azilia includes ten species found mainly in the Neotropical region (Bryant, 1940; di Caporiacco, 1954; Keyserling, 1881a; Mello-Leitão, 1940, 1948; O. P. Cambridge, 1889, 1893). The only species with a geographical range extending to the north temperate regions is A. affinis O. P. Cambridge, 1893 (Levi, 1980). These spiders build horizontal webs with numerous radii and spirals – more than 30 each, a closed hub and secondary radii (Fig. 3C). Their webs are usually found between tree buttresses and similar cavities; at night time the spider is often found at the centre of the web.   
 Taxonomy: There are no taxonomic revisions or phylogenetic analyses that test the monophyly of this genus. Only the taxonomy of A. affinis has been revised for the USA (Levi, 1980). Both sexes are known only in three of the described species: A. affinis, A. marmorata, and A. guatemalensis O. P.- Cambridge, 1889. The male pedipalpal femur and tibia of A. marmorata (Mello-Leitão, 1948) are extremely long, resembling those of Metleucauge eldorado Levi, 1980 (Fig. 78F). Azilia marmorata and other species have embolic apophyses. The other seven species are known only from female specimens except Azilia vachoni (di Caporiacco, 1954) which was described from an immature specimen. Some aspects of the behaviour of Azilia species have been studied, for example, the extended position of legs I and II while the spider is resting, how these spiders initiate airborne lines, and to some extent, their web building behaviour (Eberhard, 1982, 1984, 1987). The diagnosis and description are based on A. affinis, A. histrio, A. marmorata from the Dominican Republic, and A. guatemalensis from Mexico. As the anatomy of A. affinis has been studied in more detail, many characters in the description refer to this species. The phylogenetic placement of Azilia is far from clear. Previous to this study two hypotheses existed about the sister taxon of Azilia: either as sister to Dolichognatha (Hormiga et al., 1995: fig. 141 A), or as sister to all other leucaugines (Álvarez-Padilla, 2007: fig. 142 B). We coded specimens of A. affinis for the morphology in the phylogenetic analysis.
description: Published as part of Álvarez-Padilla, Fernando & Hormiga, Gustavo, 2011, Morphological and phylogenetic atlas of the orb-weaving spider family Tetragnathidae (Araneae: Araneoidea), pp. 713-879 in Zoological Journal of the Linnean Society 162 (4) on pages 745-748, DOI: 10.1111/j.1096-3642.2011.00692.x, http://zenodo.org/record/5440885