Isala L. Koch, 1876

Machado, Miguel & Teixeira, Renato Augusto, 2021, Phylogenetic relationships in Stephanopinae: systematics of Stephanopis and Sidymella based on morphological characters (Araneae: Thomisidae), Organisms Diversity & Evolution (New York, N. Y.) 21 (2), pp. 281-313 : 296-297

Isala L. Koch, 1876

Type species: Isala punctata L. Koch, 1876

Diagnosis. Species of Isala resembles those of Borboropactus by their cryptic behaviour, with individuals frequently presenting lichen, sand and other soil particles attached to their tegument, and by the elongated body shape: prosoma and opisthosoma longer than wide, and anterior legs (I and II) aligning parallel to each other and directing frontwards. However, males of Isala can be recognized and distinguished by their well-developed palpi with cymbial projection, long and curved RTA and filiform embolus, lacking the median apophysis and the conductor, observed for Borboropactus . Females of this latter have acute lateral projections on the epigynal plate, known as “epigynal teeth”, while females of Isala present a flattened atrium and folds of the epigynal plate strongly sclerotized, forming almost like “pockets” that protect and hide the copulatory ducts (in ventral view). Moreover, the ocular arrangement in Isala is characterized by the ALE noticeably bigger than the AME and the anterior eye row strongly recurved, while in Borboropactus the anterior eyes are all similar in size and arranged in a straight row.

Taxonomic acts

Stephanopis arenata Machado, 2019 : Holotype female from Scotia Sanctuary, New South Wales, Australia, 33° 07′ 36″ S 141° 10′ 40″ E (AMS KS.128001, examined). Transferred to Isala — Isala arenata (Machado, 2019) comb. nov.

Stephanopis cambridgei Thorell, 1870 : Holotype female from Australia (NHRS 1163, examined). Transferred to Isala — Isala cambridgei (Thorell, 1870) comb. nov.

Stephanopis longimana Thorell, 1881 : Holotype female from Cape York, Queensland, Australia, 10° 42′ S 142° 31′ E (MCSNG, examined). Transferred to Isala — Isala longimana (Thorell, 1881) comb. nov.

Stephanopis palliolata Simon, 1908 : Syntype male from Wooroloo, Western Australia, Australia (ZMB 20726, examined). Transferred to Isala — Isala palliolata (Simon, 1908) comb. nov.

Stephanopis rufiventris Bradley, 1871 : Holotype female from, Tia (40 km east of Walcha), New South Wales, Australia, 31° 12′ S 151° 48′ E (OUMNH 618, examined). Transferred to Isala — Isala rufiventris ( Bradley, 1871) comb. nov.

Stephanopis similis Machado, 2019 : Holotype female from Kanangra Boyd National Park (Boyd plateau near to Jenolan Caves), New South Wales, Australia, 34° 03′ S 150° 05′ E (AMS KS.30026, examined). Transferred to Isala — Isala similis (Machado, 2019) comb. nov.

Stephanopis spiralis Machado, 2019 : Holotype female from Koorawatha National Reserve, New South Wales, Australia, 34° 01′ 55″ S 148° 35′ 59″ E (AMS KS.114827, examined). Transferred to Isala — Isala spiralis (Machado, 2019) comb. nov.

Composition. After the taxonomic acts listed hereinafter, we recognize Isala as a genus with Australian distribution, composed of eight valid species: Isala punctata L. Koch, 1876 ; Isala arenata (Machado, 2019) comb. nov.; Isala cambridgei (Thorell, 1870) comb. nov.; Isala longimana (Thorell, 1881) comb. nov.; Isala palliolata (Simon, 1908) comb. nov.; Isala rufiventris ( Bradley, 1871) comb. nov.;