Stasiasticopterus Ren, Tian, Grossi, Zou & Gustafsson, 2024

Ren, Mengjiao, Tian, Chunpo, Grossi, Alexandra A., Zou, Fasheng & Gustafsson, Daniel R., 2024, Cryptic genera, cryptic species: phylogeny of the genus Philopteroides Mey, 2004, sensu lato, with descriptions of two new genera and one new species, Arthropod Systematics & amp; Phylogeny 82, pp. 585-605 : 585-605

Stasiasticopterus Ren, Tian, Grossi, Zou & Gustafsson gen. n.

Bitrabeculus Uchida, 1948: 317 in partim.

Philopteroides Mey, 2004: 173 in partim.

Type species.

Philopteroides flavala Najer & Sychra [in Najer et al.], 2012 a.

Diagnosis.

Species in Stasiasticopterus gen. n. can be separated from species of Philopteroides by the following combination of characters: 1) mesosome broad (rectangular or of more irregular shape), and clearly delineated ventrally in Philopteroides (Figs 2–5 ), but completely fused to basal apodeme and visible only as vague dorsal plate in Stasiasticopterus (Figs 13–17 ); 2) gonopore simple, extended distally in Philopteroides (Figs 2–5 ), but more complicated, with numerous small thickenings and ridges in Stasiasticopterus (Figs 13–17 ); 3) parameres fleshy, loosely articulated with basal apodeme and not strongly convergent in Philopteroides (Figs 2–5 ), but smaller, harder, tightly convergent in Stasiasticopterus (Figs 13–17 ); 4) male tergopleurite IX + X medianly continuous in Philopteroides , but medianly interrupted in Stasiasticopterus .

Possibly, species of these two genera may be separated on preantennal characters as well. In Stasiasticopterus the dorsal preantennal suture always reaches the lateral margin of the head at the site of as 1, and the marginal carina may be divided at the same point (but this is not always clear, and the carina may be just indented in some species); this would represent state D 1 in the schematics of the preantennal head published by Mey (2004). In published photos and illustrations, it seems Philopteroides typically represents state D 2 in the same scheme, with a notched but not interrupted marginal carina, and a suture that does not reach the lateral margin of the head. Possibly, the state of the dorsal preantennal suture is a better diagnostic character than the state of the marginal carina, but more species need to be examined before this character can be evaluated properly.

Moreover, the structure of the dorsal anterior plate may consistently differ between the two genera, in that the plate is generally broader and with the posterior extension thickened and associated with internal carinae in some Philopteroides , but more narrow and without such thickening of the posterior elongation in Stasiasticopterus .

Females can presently only be identified based on the preantennal characters described above, and by genetic data. However, both preantennal characters need verification, and are not clearly illustrated for some species.

Description.

Small lice of the head louse ecomorph (sensu Johnson et al. 2012). Frons deeply and narrowly emarginate, with median margin secondarily sclerotized. Dorsal preantennal suture completely surrounds dorsal anterior plate and reaches lateral margin of head at site of as 1; plate slender with no internal carinae and with posterior elongation not thickened. Marginal carina may be interrupted at site of as 1. Trabecula present. Antennae sexually monomorphic. Transverse carinae present. Temporal setae os, mts 1 and mts 3 macrosetae, mts 3 typically longer than the others. Dorsal head sensilla s 1 – 4, pts, and pns present. Pro- and pterothorax not divided medianly; ppss on posterior margin of pronotum; mms as continuous row on posterior margin of pteronotum. Prosternum present; mesometasternum absent. Metepisterna not sclerotized laterally. Abdomen broad, tergopleurites II – IX + X (male) or II – VIII (female) medianly divided, each with rows of macrosetae on posterior margin; anterior seta of tergopleurite II present. Sternal plates variable between species, typically present on at least segments III – VI, generally broader in male than in female; accessory sternal plates present in at least some segments, in males often fused to central sternal plates at least in more posterior segments. At least some thorn-like sts present on most of segments II – VI. Basal apodeme slender, completely fused to mesosome; mesosome may be visible as vague plate on dorsal side, if so, never rectangular. Gonopore large, with numerous sclerites, ridges, and in some species with fringed distal extensions; mesosomal setae not visible in more species. Parameres strongly sclerotized, strongly convergent, with pst 1 – 2 sensilla. Female subgenital plate not reaching vulval margin; vulval margin with 1–2 rows of shorter vss and longer vms. Subvulval plates present.

For more complete illustrations of this genus, see Gustafsson et al. (2022 b).

Host associations.

Presently only known from bulbuls ( Passeriformes : Pycnonotidae ).

Geographical range.

Described species only known from Asian hosts ( China, Japan, Philippines, Vietnam), but undescribed species from African hosts closely related and probably belong to Stasiasticopterus .

Etymology.

The genus name is derived from Greek “ στασιαστικός ” (stasiastikós), meaning “ factious, seditious ”. This refers to the fact that the lice in this group are morphologically almost identical to those of Philopteroides , but insist on forming their own, presumably convergently evolving, clade. To this is added an ending derived from “ - πτερόν ” (pterón), Greek for “ wing ”, and here used as an indicator of relationship with the genus Philopterus Nitzsch, 1818 . Gender: masculine.

Included species.

See Table 3 .

Figures

Figures 2–17. Comparison of the male genitalia of some species of Philopteroides Mey, 2004, Coronedax gen. n., and Stasiasticopterus gen. n. All figures redrawn from their original descriptions (Tandan 1955; Mey 2004; Valim & Palma 2013), unless otherwise noted. Illustrations have been rescaled to be roughly the same size. Illustrations are in ventral view, unless otherwise noted. No illustrations of the genitalia have ever been published for Philopteroides lineatus (Giebel, 1874), Philopteroides mitsusui (Uchida, 1948), or Stasiasticopterus kayanobori (Uchida, 1948). 2 Philopteroides novaezelandiae Mey, 2004. 3 Philopteroides xenicus Mey, 2004. 4 Philopteroides fuliginosus Valim & Palma, 2013. 5 Philopteroides macrocephalus Valim & Palma, 2013. 6 Philopteroides gigas Najer et al., 2016. 7 Philopteroides sinancorellus Najer et al., 2016. 8 Philopteroides sclerotifrons (Tandan, 1955); no scale in original. 9 Philopteroides pilgrimi Valim & Palma, 2013. 10 Philopteroides beckeri (Mey, 2004) (redrawn from Valim & Palma 2013). 11 Coronedax terpsiphoni (Najer & Sychra [in Najer et al.], 2012 a). 12 Coronedax longiceps sp. n. 13 Stasiasticopterus longiclypeatus (Gustafsson et al., 2022 b). 14 Stasiasticopterus holosternus (Gustafsson et al., 2022 b). 15 Stasiasticopterus haerixos (Gustafsson et al., 2022 b). 16 Stasiasticopterus flavala (Najer & Sychra [in Najer et al.], 2012 a. 17 Stasiasticopterus cucphuongensis (Mey, 2004) (redrawn from Gustafsson et al. 2022 b). Bold grey lines signify the generic divisions used here; narrow grey lines signify groups that are morphologically different from the type species of the respective genera, but where there is insufficient data to propose addition (e. g., subgeneric) limits. The two species here considered incerta sedis are placed in separate groups, pending further investigations. — Abbreviations used: BA = basal apodeme; GP = gonopore; MS = mesosome; lpmes = lateral posterios mesosomal setae; PM = parameres; pst 1–2 = parameral setae 1–2 (2 distal to 1).