Azilia, KEYSERLING, 1881

Álvarez-Padilla, Fernando & Hormiga, Gustavo, 2011, Morphological and phylogenetic atlas of the orb-weaving spider family Tetragnathidae (Araneae: Araneoidea), Zoological Journal of the Linnean Society 162 (4), pp. 713-879 : 745-748

publication ID

https://doi.org/ 10.1111/j.1096-3642.2011.00692.x

DOI

https://doi.org/10.5281/zenodo.10545804

persistent identifier

https://treatment.plazi.org/id/7D5E87AD-C049-5524-FCEE-4CB5D091FA06

treatment provided by

Valdenar

scientific name

Azilia
status

 

AZILIA KEYSERLING, 1881 View in CoL ( FIGS 2B View Figure 2 , 3C View Figure 3 , 13–17 View Figure 13 View Figure 14 View Figure 15 View Figure 16 View Figure 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 View Figure 2 , 14A, B View Figure 14 ); male pedipalp without conductor ( Fig. 16A–F View Figure 16 ); epigynum flat ( Fig. 15A, B View Figure 15 ); spermathecae walls weakly sclerotized ( Figs 15C, D View Figure 15 , 17B View Figure 17 ); and absence of femoral trichobothria ( Fig. 14G, H View Figure 14 ).

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 View Figure 14 ). Clypeus height less than one AME diameter. Anterior surface of chelicerae smooth ( Fig. 14C View Figure 14 ). Cheliceral boss present. Sternum longer than wide. Labium trapezoidal and rebordered. Endites rebordered, longer than wide ( Fig. 14E View Figure 14 ). 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 View Figure 13 ), leaf-shaped apically ( Fig. 13D View Figure 13 ). Tracheal spiracle near the spinnerets, with more than four accessory glands on each side ( Fig. 13B, C View Figure 13 ). 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 View Figure 13 ). Epigynum flat, copulatory openings as two pits posteriorly orientated ( Fig. 15A, B View Figure 15 ). Spermathecal walls weakly sclerotized, accessory gland openings arranged in groups ( Figs 15F, G View Figure 15 , 17B View Figure 17 ). Fertilization and copulatory ducts shorter than half the spermathecae length, coiled ( Figs 15E View Figure 15 , 17B View Figure 17 ).

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 View Figure 13 ). 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 View Figure 16 ). Paracymbium shorter than half the cymbium length, covered with macrosetae, and its attachment to the cymbium well sclerotized ( Fig. 16D View Figure 16 ). Conductor absent. Sperm duct coiled ( Fig. 17A View Figure 17 ). Embolus lamelliform, curving less than one turn ( Figs 16F View Figure 16 , 17C View Figure 17 ).

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 View Figure 3 ). 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 View Figure 78 ). 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.

PMS

Peabody Essex Museum

O

Botanical Museum - University of Oslo

P

Museum National d' Histoire Naturelle, Paris (MNHN) - Vascular Plants

I

"Alexandru Ioan Cuza" University

A

Harvard University - Arnold Arboretum

B

Botanischer Garten und Botanisches Museum Berlin-Dahlem, Zentraleinrichtung der Freien Universitaet

Kingdom

Plantae

Phylum

Tracheophyta

Class

Magnoliopsida

Order

Apiales

Family

Apiaceae

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