Sikongia new genus Philopterus (Goniodes) Nitzsch, 1818: 293. In partim. “Genus 4” Gustafsson et al., 2024c: 98. Type species: Goniodes tetraophasis Chou & Liu, 1986: 317. Diagnosis. The relationships between species of Sikongia and species placed in Goniodes by Price et al. (2003) are unknown, as the only known species of Sikongia is not similar morphologically to any other known species of goniodid. The closest relatives may be in Gonotyles, particularly in the subgenus Syrmatichares, with which Sikongia shares the following characters: meso- and metasterna and associated setae absent (Figs 74–75); male scape swollen and elongated, but with posterior process present only as a small bulge with an apical seta (Fig. 76); coni not bent posteriorly in either sex (Figs 76–77); male tergopleurite IX not fused to central plate (Fig. 78); female abdominal segment IX–XI extended posteriorly to form lateral seta-bearing lobes (Fig. 79); triangular processes and bifid structure both absent in female genitalia (Fig. 80). However, many of these characters are widely distributed within Goniodes sensu Price et al. (2003) and may be homoplasies. Sikongia can be separated from Gonotyles (Syrmatichares) by the following characters: pteronotum with three lpts on each side in Sikongia (Fig, 74), but with two lpts on each side in Gonotyles (Syrmatichares) (Fig. 37); ventral side of male abdominal segments IX–XI with multiple (more than five) macrosetae on each side in Gonotyles (Syrmatichares) (Fig. 37), but without ventral macrosetae except on distal margin in Sikongia (Fig. 74); tergopleurites with rows of tps microsetae separating tcs and psc in Gonotyles (Syrmatichares) (Figs 37–38),but with tps mesosetae in Sikongia (Figs 74–75) and only tergal microsetae intercalated with mesosetae near median end of tergopleurites; paratergal plate II in both sexes of Sikongia with dense rows of macrosetae one each side (Figs 74–75), but with few (fewer than three) ps on segment II in Gonotyles (Syrmatichares) (Figs 37–38); male genital opening with serrated sclerite on each side in Gonotyles (Syrmatichares) (Fig. 43), but without such sclerite in Sikongia (Fig. 78); female vulval margin not extending beyond distal margin of abdomen, strongly convex with lateral setae-bearing lobes in Gonotyles (Syrmatichares) (Fig. 44), but extending beyond distal margin of abdomen, deeply bilobed but without setae-bearing lobes in Sikongia (Figs 79–80); vulval setae divided into vms mesosetae, vss thorn-like setae, vss (?) slender setae, and vos microsetae in Gonotyles (Syrmatichares) (Fig. 44), but all vulval setae more or less similar as microsetae in Sikongia (Fig. 80). Male genitalia of Sikongia were not illustrated in detail by Chou & Liu (1986) and are absent in all known specimens of S. tetraophasis (see Gustafsson et al. 2024a: 544– 545). Based on the illustrations of Chou & Liu (1986: fig. 3a), the male genitalia of S. tetraophasis differ from those of Gonotyles (Syrmatichares) in having parameres distinct and not fused to either basal apodeme or mesosome, and by having an elongated T-shaped structure on the distal basal apodeme. New material of S. tetraophasis is needed to evaluate the differences in the male genitalia adequately. Sikongia can be separated from Goniodes sensu stricto by the following characters: male scape with distally squamous process not bearing any setae in Goniodes (Fig. 4), but with only a slight seta-bearing bulge in Sikongia (Fig. 76); coni bent posteriorly in both sexes of Goniodes (Figs 4–5), but not in Sikongia (Figs 76–77); head setae ads, pas, pns, os all macrosetae in Sikongia (Fig. 76), but mesosetae in Goniodes (Fig. 4); mts4 and mts5 both situated on occipital process in Goniodes (Fig. 4), but only mts5 on occipital process in Sikongia (Fig. 76); postero-lateral corners of pteronotum flattened so that both lpts (of which there are two on each side) and ipts are lateral in Goniodes (Figs 1, 3,), but rounded so that only lpts (of which there are three on each side) are lateral in Sikongia (Figs 74–75); mesosternum, mss, and mets all present in Goniodes (Figs 1, 3), but all absent in Sikongia (Figs 74–75); male tergopleurite IX fused to central plate in Goniodes (Fig. 1), but not fused in Sikongia (Fig. 74); female abdominal segment IX+X expanded distally to form setae-bearing lobes in Sikongia (Figs 79–80), but no such lobes in Goniodes (Fig. 3); male tergopleurites with rows of tps microsetae separating tcs and psc in Goniodes (Fig. 1), but with tps mesosetae in Sikongia (Fig. 74) and only tergal microsetae intercalated with tcs near median end of tergopleurites; paratergal plate II in both sexes of Sikongia with dense rows of macrosetae one each side (Figs 74–75), but with no ps on segment II in Goniodes (Figs 1, 3); both sexes of Sikongia with rows of microsetae on ventral surface of at least some segments (Figs 74–75), but no microsetal rows in Goniodes (Figs 1, 3); bifid structure of female genitalia present in Goniodes (Fig. 8), but absent in Sikongia (Fig. 80); female vulval margin not extending beyond distal margin of abdomen, straight with lateral setae-bearing patches in Goniodes (Fig. 8), but extending beyond distal margin of abdomen, deeply bilobed but without setae-bearing lobes in Sikongia (Figs 79–80); vulval setae divided into vms mesosetae, vss (?) slender setae, and vos microsetae in Goniodes (Fig. 8), but all vulval setae more or less similar as microsetae in Sikongia (Fig. 80). Based on the illustrations of the male genitalia of S. tetraophasis by Chou & Liu (1986), Sikongia can be separated from Goniodes sensu stricto on the following additional characters: mesosome elongated triangular, distally bifurcated, with rugose lateral corners and a distinct structure presumed to be the gonopore in Goniodes (Figs 6–7), but rounded rectangular with no distinct structures in Sikongia (Chou & Liu 1986: fig. 3a); parameres widening distally in Goniodes (Figs 6–7), but tapering distally in Sikongia. Description Both sexes. Large chewing lice of the Goniodes body louse ecomorph (Figs 74–75). Head broader than long, frons gently rounded to somewhat flattened (Fig. 76). Marginal carina uninterrupted, terminating proximally in elongated preantennal nodi. Ventral carina uninterrupted; clypeo-labral suture absent. Coni not bent posteriorly (Figs 76–77). Antennae sexually dimorphic: male scape swollen and elongated compared to that of female, with posterior margin bulging slightly at about mid-length, bearing one seta on the bulge; male pedicel swollen and slightly modified in shape compared to female; male flagellomere I extended distally into broad, distally tapering process. Eyes large. Temples somewhat angular laterally; occipital process present, in males directed somewhat lateral. Head chaetotaxy: dsms, ads, pas, os, pns, pcs and avs2 all meso- or macrosetae; mts1 and mts3 only temporal macrosetae; only mts5 situated on occipital process; head sensilla s1–2 and s6 present in both sexes; in male a patch of dorsal sensilla present centrally in post-antennal head. Rhombic sclerite present, may be fused to pronotum. Pronotum rounded posteriorly, with ppss on postero-lateral corner. Pteronotum roughly pentagonal, with postero-lateral corners rounded so that only lpts (of which there are three) are lateral; ipts sublateral; smns without associated sensillum; mpts on or just posterior to pteronotum. Meso-and metasterna and associated setae absent. Proepimera large, curling around coxae II, but not fused medianly. Metepisterna not sclerotised medially. Abdomen rounded in male, more elongate in female (Figs 74–75); tergopleurite II not fused to pteronotum in either sex, and tergopleurites II–VIII medianly separated. Male tergopleurite IX not fused to central plate, but may overlap (Fig. 78). Female tergopleurites IX–XI all fused together and medianly continuous, with lateral section extended distally to form setae-bearing lobes; central part of female tergopleurite IX–XI with distinct reticulation (Fig. 79). Central sternal plates absent, but abdominal segments II–VI in both sexes with lateral accessory sternal plates. Male abdominal chaetotaxy: tergopleurites II–VII with rows of tcs+tps, with small numbers of microsetae intercalated with tcs+tps in more anterior segments, particularly near the median ends of tergopleurites; tergopleurites II–VIII with at least three psc on each side, but median ones indistinguishable in length from tcs+tps rows; ventral side of abdominal segments II–VIII with one (two on VII) sts on each side, on II–VI with additional rows of microsetae. Female abdominal chaetotaxy: tergopleurites II–III with dense double rows of tcs+tps, tergopleurites IV–VIII each with one row of tcs, gradually more sparse in more posterior segments, with (tps?) microsetae around median ends of tergopleurites on some more posterior segments; on tergopleurites II–III psc e cannot be distinguished from tergal rows, on tergopleurites IV–VII three psc on each side; on tergopleurite IX–XI a row of short mesosetae submarginally (Fig. 79); ventral sides of abdominal segments II–VIII with one sts on each side, at least on segments III–V, with additional microsetae. Male subgenital plate small; female subgenital, subvulval, and postvulval plates absent. Male genitalia not present in any examined specimens; based on illustrations by Chou & Liu (1986: fig. 3a) of (now lost) type specimens, the basal apodeme is long (reaching abdominal segment II with not everted), not fused to either mesosome or parameres, but bears an elongated T-shaped structure centrally. Mesosome rounded rectangular, seemingly without any distinct structures apart from perhaps centrally. Parameres elongated, slender, tapering distally. Female genitalia without bifid structure or triangular processes (Fig. 80). Vulval margin extended distally to reach beyond distal margin of abdomen, forming a narrowly pointed lobe on each side separated by a narrow, deep emargination. Vulval setae not easily separated into sets, with numerous (more than 60) microsetae or sensilla on each side scattered in subvulval area.

Published as part of Gustafsson, Daniel R., Li, Zhu, Tian, Chunpo, Ren, Mengjiao, Sun, Xiuling & Zou, Fasheng, 2025, Revision of genera in Goniodidae (Phthiraptera: Ischnocera) parasitising gamefowl (Aves: Galliformes) with descriptions of six new genera, one new subgenus and seven new species, pp. 1-99 in Zootaxa 5731 (1) on pages 75-80, DOI: 10.11646/zootaxa.5731.1.1, http://zenodo.org/record/18019316