Pavoniocotes parviceps ( Piaget, 1880 ) Gustafsson & Grossi & Ren & Zou, 2023

Gustafsson, Daniel R., Grossi, Alexandra A., Ren, Mengjiao & Zou, Fasheng, 2023, The Goniodidae (Phthiraptera: Ischnocera) of peafowl (Aves: Galliformes: Pavo), with description of a new genus, Journal of Natural History 57 (17 - 20), pp. 996-1048 : 1036-1038

Pavoniocotes parviceps ( Piaget, 1880) comb. nov.

( Figures 24–37 )

Goniodes parviceps Piaget, 1880: 277 .

Goniocotes parviceps (Piaget), 1880 ; Hopkins and Clay 1952: 149.

Goniodes yngarejsuf Eichler, 1950: 4 (tentative synonymy).

Type host

Pavo cristatus Linnaeus, 1758 – Indian peafowl.

Type locality

Zoological Garden, Rotterdam, Netherlands.

Other hosts

Pavo muticus Linnaeus, 1766 – green peafowl.

Description

Male ex Pavo cristatus . Frons broadly flattened ( Figure 26 ), temples more or less parallel, no distinct bulge at site of mts1 or mts5. Head setae as1, as3, pcs clearly dorsal; pos, mts2, mts4 large, thorn-like; head sensilla s6–7 present. Triangular extension of scape with spike-like apical seta. Thoracic and abdominal segments as in Figure 24 ; prothorax flaring laterally; tergopleurite VIII with tps on each side; accessory lateral sternal plates present on segments II–VII. Male genitalia asymmetrical ( Figures 28–29 ), and highly variable between specimens; illustrations of genitalia therefore approximate. The only clearly sclerotised parts of the dorsal genitalia are paired, rather short, and asymmetrically twisted parameres ( Figure 28 ), which have densely rugose or minutely spiculate distal ends. Other sclerites of dorsal side variable and asymmetrical. Ventral side dominated by single asymmetrical central plate, bearing at least 2 sensilla on one side ( Figure 29 ). Anterior to this plate are at least 1 transverse, crooked sclerite and 2 smaller, bar-like sclerites unconnected medianly. Distal to central plate are paired elongated sclerites, which may be ventral surface of parameres, bearing at least 1 sensillum each on inner margin. Genital sac dorsally with broadly U-shaped band of spiculation, ventrally band of spiculation widened laterally but narrow medianly. Measurements as in Table 1 .

Female ex Pavo cristatus . Frons rounded ( Figure 25 ), temples widening lateral to eye, bulging slightly at mts5. Head setae as1, as3, pcs ventral; pos, mts2, mts4 slender microsetae; head sensilla s6–7 absent. Antennae not modified. Thoracic and abdominal segments as in Figure 25 ; psps absent on at least tergopleurite II, in some specimens also on tergopleurite III; accessory lateral sternal plates present on segments II–VIII. Vulval margin variable between specimens, typically more or less flat to slightly convex ( Figure 30 ), with 25–28 slender vms and 2–4 thorn-like vss on each side. Hyaline microsetae of post-vulval area generally extend anteriorly to approach vulval margin. Measurements as in Table 1 .

Male ex Pavo muticus . As for the male described above, except: head proportionately broader with more narrowly flattened frons ( Figures 31 , 33 ). Tergopleurites generally with fewer tps one each side, and tps often absent on at least one side of tergopleurite VII; however, variation in numbers overlapping in examined specimens, and probably not diagnostic. Parameres generally longer and narrower ( Figure 35 ). Central plate of ventral mesosome ( Figure 36 ) may have more complicated ridges and shapes than in specimens from type host, but variation in morphology great, and differences not diagnostic. Absence of anterior transverse sclerite may be artefact. Measurements as in Table 1 .

Female ex Pavo muticus . As for the female described above, except: head shape slightly different with temples more rounded and frons slightly narrower ( Figure 32 ). Tergopleurites generally with fewer tps on each side, but numbers variable between specimens and between sides of same specimen. Vulval margin generally more convex ( Figure 37 ), with 25–31 slender vms and 2–4 thorn-like vss one each side. Hyaline microsetae of post-vulval area restricted to distal parts of fleshy lobes and area near posterior margin of abdomen. Measurements as in Table 1 .

Material examined

Non-type specimens. Ex Pavo cristatus : 1♂, 1♀, Delhi [ India], November 1899, leg. R. Meinertzhagen, 4452, NHMUK010675814–5 ( NHML). 3♂, 2♀, Delhi [ India], November 1912, leg. R. Meinertzhagen, 3122, NHMUK0101675813 , NHMUK010675817 ( NHML). 1♂, 1♀, London Zoo [ United Kingdom] (marked ̍India or Ceylon̾), 8 June 1970, no collector, ex 167/70, Brit. Mus. 1970–370, NHMUK010675816 ( NHML) .

Ex Pavo muticus : 2♂, 2♀, S. Annam [ Vietnam], no collector or date, BM1927-248 , NHMUK010675824 ( NHML) . 1♂, 5♀, Burma ( Zoo ), January 1938, leg. R. Meinertzhagen, 10,752, NHMUK010675826 ( NHML) . 3♂, 3♀, 1 teneral male(?), Sa Ban Pha Hang , Nan Province, Thailand, 8 December 1961, leg. K. Thonglongya, V139, Brit. Mus. 1965–630, NHMUK0101675829 ( NHML) .

Remarks

We here tentatively accept the synonymy of G. yngarejsuf with G. parviceps . Eichler (1950) examined only a single female (not studied by us), which is partially illustrated and poorly described. The illustration of the outline of the head ( Eichler 1950, fig. 3) does not exactly correspond to any specimens of P. parviceps we have seen, but the narrow marginal carina is more similar to P. parviceps than to G. rectangulatus . Eichler̾s illustration of the female genitalia ( Eichler 1950; fig. 4) shows that G. yngarejsuf has a dense row of slender setae along the vulval margin, which is indicative of Pavoniocotes rather than Goniocotes . However, the vulval margin is more strongly convex than in any specimens we have seen. The absence of a subgenital plate or other sclerotised structures near the vulval margin in P. parviceps means there may be more flexibility in the shape of this margin in P. parviceps than in species with sclerotised subgenital plates. Moreover, the number of specimens we have examined is low, and potentially variation in this character may be large. It should be noted that Eichler̾s specimen came from a zoo animal, and P. cristatus may therefore not be the natural host of G. yngarejsuf . The type specimen is in need of reexamination before this synonymy can be made definite.

Specimens from Pavo muticus differ slightly from specimens from the type host as described above, but differences in the structure of the male genitalia are difficult to assess, as specimens vary slightly. Moreover, the chaetotaxy of the abdomen and the vulval margin varies between specimens, and overlap between specimens from the two host species. Genetic data will be needed to establish whether these two populations constitute separate evolutionary lineages, or whether they are best treated as a single, somewhat variable, species. Here, we tentatively consider material from the two host species conspecific, but illustrate specimens from P. muticus separately.

Figures

Figure 24. Pavoniocotes parviceps (Piaget, 1880) ex Pavo cristatus Linnaeus, 1758, male habitus, dorsal and ventral views.

Figure 25. Pavoniocotes parviceps (Piaget, 1880) ex Pavo cristatus Linnaeus, 1758, female habitus, dorsal and ventral views.

Figures 26–30. Pavoniocotes parviceps (Piaget, 1880) ex Pavo cristatus Linnaeus, 1758. 26, male head, dorsal and ventral views. 27, female antenna and conus, ventral view. 28, male genitalia, dorsal view. 29, male genitalia, ventral view. 30, female genitalia and abdominal segments VII–XI, ventral view.

Figure 31. Pavoniocotes parviceps (Piaget, 1880) ex Pavo muticus Linnaeus, 1766, male habitus, dorsal and ventral views.

Figure 32. Pavoniocotes parviceps (Piaget, 1880) ex Pavo muticus Linnaeus, 1766, female habitus, dorsal and ventral views.

Figures 33–37. Pavoniocotes parviceps (Piaget, 1880) ex Pavo muticus Linnaeus, 1766. 33, male head, dorsal and ventral views. 34, female antenna and conus, ventral view. 35, male genitalia, dorsal view. 36, male genitalia, ventral view. 37, female genitalia and abdominal segments VII–XI, ventral view.