Linyphiinae, Blackwall, 1859

Silva-Moreira, Thiago Da, Kulkarni, Siddharth & Hormiga, Gustavo, 2025, A total evidence phylogenetic analysis of the spider family Linyphiidae (Araneae, Araneoidea), Zootaxa 5685 (1), pp. 1-78 : 47-48

Linyphiinae ( Figs 4 and 5 ) new circumscription

Linyphiinae (sensu Tanasevitch 2025) is not monophyletic in any of our analyses. The genera assigned to this subfamily were found scattered through several different lineages across the tree. The polyphyly of Linyphiinae is neither new (e.g., Wang et al. 2015) nor unexpected, given the very loose definition of the subfamily ( Millidge, 1993) and the diverse taxa assigned to it. In this study, we propose a new circumscription for the Linyphiinae subfamily that will include most of the traditionally assigned genera to this subfamily, with some exceptions that would be found mainly within Clade A (see TAXONOMY section for details).

The newly circumscribed Linyphiinae is recovered in all TE analyses with solid support from both ML and Bayesian analyses. Linyphiinae is supported by five synapomorphies ( Fig. 11 ): a compact lamella characteristica (char 113) with a posterior apophysis (char 119), an epigynum with dorsal plate socket (char 131) or a dorsal plate scape (char 132) without socket (char 134), a cymbium dorsal or meso-dorsal oriented (char 113), and an ellipsoid tegulum (char 59). The compact lamella characteristica (LC) and the scape without socket are non-homoplasious synapomorphies of this clade.

Labullinyphia tersa ( Figs 4 , 11 )

Van Helsdingen (1985) considered Labullinyphia tersa , from Sri Lanka, closely related to Labulla (hence the new generic name and combination), Microlinyphia Gerhardt , and Frontinellina van Helsdingen (especially to F. locketi van Helsdingen, 1970 ), based on similarities of the female genitalia and despite the presence of the single dorsal spine on tibia IV. Millidge (1993) illustrated the internal epigynal structures and provided a short description of them. The aforementioned studies on Labullinyphia were based only on the female, as the male remained unknown. Benjamin & Hormiga (2009) provided the first description of the male and based on a phenotypic cladistic analysis, suggested that Labullinyphia nested within erigonines, as sister to Erigone . The erigonine placement of Labullinyphia was supported by synapomorphies such as the absence of epiandrous fusules, retention of araneoid PLS triplet in adult males, absence of the female pedipalpal claw, desmitracheate system, and the male retrolateral tibial apophysis, which are well-known traits of erigonines. Those results were later corroborated by the analysis of Silva-Moreira & Hormiga (2021).

Molecular analyses from Wheeler et al. (2017) and the present study ( Fig. 4 ) place L. tersa outside erigonines. The results of our MORPH matrix analysis (both equal and implied weights) are congruent with previous studies that used solely phenotypic data ( Benjamin & Hormiga 2009; Silva-Moreira & Hormiga 2022) and place Labullinyphia in Erigoninae . Surprisingly, none of the analyses that used molecular data placed this genus within the erigonines (but on TNT, L. tersa was retrieved as sister group to Labulla thoracica ). Irfan & Peng (2019) recently described a second species in the genus from China, morphologically similar to the Sri Lanka species and also exhibiting many erigonine synapomorphies. The lack of congruence between phenotypic and molecular data is intriguing, and given the long list of morphological features shared between Labullinyphia and the erigonines, we suspect that the available sequence data for L. tersa is based on a mislabeling error. Future work will require de novo sequencing representatives of this genus to resolve this paradox. We thus consider Labullinyphia as incertae sedis.

Linyphia clade ( Figs 4 , 11 )

The clade that includes Linyphia Latreille is found as one of the lineages of Linyphiinae and comprises, in addition to Linyphia , the genera Microlinyphia , Neriene Blackwall , and Pityohyphantes Simon ( Fig. 4 ). While a lineage with Linyphia , Pityohyphantes , and Microlinyphia is very consistent across analyses, the placement of Neriene in it is much more unstable. Some of our analyses (e.g., M4_RAXML) place all Neriene species together, including three undescribed species, one from the Philippines (Gen. sp. PHY_02) and two from Taiwan (Gen. sp. TW_01 and Gen. sp. TW_02). Ten synapomorphies (all of them homoplasious) support Linyphia clade ( Fig. 11 ), including a pear-shaped male palpal tibia (char 11), a flattened paracymbium (char 52) with a thin medial part (char 51), embolic division with terminal apophysis (char 104) and an epigynum with an atrium (char 142). The implied weighted tree of the MORPH dataset does imply the presence of an atrium with grooves or folds as a non-homoplasious synapomorphy of this clade. This same character in our selected optimization is found as a non-homoplasious synapomorphy of Linyphia + Microlinyphia .

Frontinella clade

The Frontinella clade is composed by Frontinella F. O. Pickard-Cambridge , Orsonwelles Hormiga , Neriene japonica (Oi) , and one unidentified linyphiid from the Philippines (Gen. sp. PHY_01— Fig. 4 ). As mentioned above, the placement of Neriene is unstable, and sometimes it is recovered as separate lineage. As we are unable to access the molecular voucher (ICZL 172) of N. japonica we cannot test this hypothesis in more detail. Nevertheless, the Frontinella clade is consistently found in all our analyses, congruent with the results of Arnedo et al. (2009) and Wang et al. (2015), as a natural group supported by 18 synapomorphies, only one of which is non-homoplasious, the presence of a cymbial pocket (char 40). Other synapomorphies include the male palp tibial macrosetae only on the ventral part (char 6), a paracymbium oriented perpendicular to the cymbium (char 47), with the basal section taller than longer (char 50) and medial (char 51)/ apical (char 52) sections absent and a radix with terminal sclerite (char 109) ( Fig. 11 )

Figures

FIGURE 4. Partial tree from the preferred hypothesis for linyphioids (M4_MB). Linyphiinae (new circumscription) (part), Labullinyphia tersa, Linyphia clade, and Frontinella clade. Black-colored squares represent nodes with posterior probability =1; gray-colored squares represent nodes with posterior probability between 0.95 and 0.99.

FIGURE 5. Partial tree from the preferred hypothesis for linyphioids (M4_MB). Linyphiinae (new circumscription) (part), MPME clade. Black-colored squares represent nodes with posterior probability =1; gray-colored squares represent nodes with posterior probability between 0.95 and 0.99.

FIGURE 11. Optimization of the phenotypic matrix characters (DELTRAN optimization) on the pruned preferred hypothesis tree of Linyphiinae’s new circumscription. Green box indicates MPME clade new circumscription. Black circles indicate nonhomoplasious optimizations (synapomorphies/ autapomorphies), while white circles indicate homoplasious transformations.