Goniodes pavonis ( Linnaeus, 1758 )

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 : 1002-1007

Goniodes pavonis ( Linnaeus, 1758)

Pediculus pavoni Linnaeus, 1758: 613 [misprint for pavonis ; see von Kéler 1940: 39].

Ricinus pavonis Linnaeus [1758] ; Latreille 1802: 389.

Nirmus tetragonocephalus Olfers, 1816: 90 [unnecessary replacement name for P. pavonis ].

Goniodes falcicornis Nitzsch, 1818: 293 [unnecessary replacement name for P. pavonis ].

̍ Nirmus pavonis Herm ̾.; Kirby and Spence 1823: 321.

Goniodes (Philopedon) falcicornis (Nitzsch) ; Stephens 1829: 333.

Goniodes falcicornis Nitzsch ,in Burmeister 1838; Harrison 1916: 76 [as synonym of G. pavonis ]

Goniodes pavonis Linné, 1758, 1916: 78 .

Goniodes tetragonocephalus Olfers, 1816, 1916: 79 [as synonym of G. pavonis ].

( Figures 1–9 )

Type host

Pavo cristatus Linnaeus, 1758 – Indian peafowl.

Neotype locality

India ( Clay 1940, p. 7).

Other hosts

Pavo muticus imperator Delacour, 1949 (Ref: Emerson and Elbel 1957).

Description

Both sexes. Head broader than long ( Figure 3 ), frons gently rounded to somewhat flattened medianly. Marginal carina uninterrupted, but slightly indented laterally at site of as1 and as2. Preantennal nodi elongated. Coni strongly curved posteriorly. Antennae sexually dimorphic. Head chaetotaxy as in Figure 3 ; as1–3, avs1 and pcs clearly ventral; os sexually dimorphic. Temples rounded, but extended posteriorly at site of mts4–5, more distinct in male than in female. Temporal carinae clearly visible. Prothorax with anterior margin indented ( Figures 1–2 ); rhombic sclerite not fused to pronotum, with posterior margin indented. Postero-lateral corner of pronotum with single ppss on each side. Proepimera not fused medianly, mesofurcal pit lateral. Mesosternal plate present, oval. Sternal setae present on both meso- and metathorax. Postero-lateral corner of pteronotum modified so that ipts are more or less posterior to lpts. Small sensillum associated with smns; mpts absent. Posterior margin of pteronotum separate from tergopleurite II in both sexes, median end gently rounded. Abdominal plates and chaetotaxy as in Figures 1–2 ; tergopleurites II–VIII extended medianly. Intertergal plates absent. Accessory lateral sternal plates present on segments II–VI as elongated, oblique ovals; central sternal plates absent. Tergopleurites IX–XI sexually dimorphic. Measurements as in Table 1 .

Male. Conus bent strongly posteriorly. Antennae modified ( Figure 3 ): scape very swollen and elongated, with single squamous thumb-like process and thickened seta on posterior margin; pedicel slightly curved with slight bulge on posterior margin in distal end; distal flagellomere I extended posteriorly, posterior margin rugose; flagellomeres II–III more or less as in female. Post-antennal head with 10–13 sensilla on each side in curved band anterior to temporal carinae; s1–2 present most posteriorly and s6 present anterior to preantennal nodi. Many dorsal head setae slightly longer in male than in female, most conspicuously the os. Temple margin more sinuous and posterior extension at mts4–5 more distinct in male. Tergopleurites II–VIII with most or all tps microsetae; only tps situated median to tergopleurites macrosetae. Abdominal segments IX–XI highly modified: tergopleurite IX small, roughly circular; medianly continuous tergopleurite X extended antero-laterally to tergopleurite IX to reach near tergopleurite VIII ( Figure 9 ). Genital opening hidden underneath posterior end of tergopleurite X, with small sclerite (tergopleurite XI?) present just posterior to genital opening ( Figure 8 ). Genital opening with row of microsetae distinct from row across tergopleurite X. Subgenital plate as in Figure 9 . Male genitalia as in Figures 5–6 . Basal apodeme shorter than more distal elements, widening distally, with central Y-shaped thickening on ventral side. Mesosome somewhat asymmetrical dorsally; elongated and deeply divided in distal end. Antero-lateral margins extended laterally into hook-shaped dorsal structures that interlock with parameral heads. Ventral mesosome with thickened anterior margin, paired distal sclerotised extensions, and more hyaline lateral lobes at around mid-length. In anterior end a U-shaped sclerite with rugose lateral margins. Parameres widened distally, blunt, with pst1–2 as microsetae on distal margin.

Female. Coni bent posteriorly, but not as distinct as in male ( Figure 4 ). Female antennae stout, but not modified ( Figure 4 ). Post-antennal head with only s2 and 2 more central sensilla visible on each side; most head setae shorter than male. Temple margin more straight and with less prominent extension at mts4–5. Tergopleurites II–VI with all or most tps macrosetae; tergopleurites VII–VIII with numerous tps microsetae on each side. Tergopleurites IX–XI fused, medianly continuous, with posterior margins indented sublaterally. Subgenital plate absent ( Figure 7 ). Internal sclerite of genitalia elongated, present on one side only. Vulval margin concave, with chaetotaxy as in Figure 7 . Subvulval plates present as small, oval plates near terminal margin of abdomen.

Material examined

Neoparatypes. 2♂, 4♀, India (Zoo), 1937, leg . R. Meinertzhagen, 8321, NHMUK010676937 ( NHML) . 3♂, India (Zoo), Jan. 1938, leg. R. Meinertzhagen, 11,135, NHMUK010676956 ( NHML) .

Non-types: 2♂, 2♀, no locality, 3 September 1967, leg. R. S. Balter, Brit . Mus. 1967–599, NHMUK010676934–5 ( NHML) .

Remarks

Clay (1940, p. 5) considered G. pavonis to be connected to her species group B through Goniodes meinertzhageni Clay, 1940 (see below). However, group B is itself not morphologically homogeneous, and comprises three different species groups. Structures such as male and female genitalia, head shape, structure of the scape, head chaeto- and sensillotaxy, and abdominal chaetotaxy suggest that species groups A and B sensu Clay (1940) comprise four different groups, though the relationships between these are difficult to assess. No other species of Goniodes is similar to G. pavonis .

Figures

Figure 1. Goniodes pavonis (Linnaeus, 1758), male habitus, dorsal and ventral views.

Figure 2. Goniodes pavonis (Linnaeus, 1758), female habitus, dorsal and ventral views.

Figures 3–7. Goniodes pavonis (Linnaeus, 1758). 3, male head, dorsal and ventral views. 4, female antenna and conus, ventral view. 5, male genitalia, dorsal view. 6, male genitalia, ventral view. 7, female genitalia and abdominal segments VII–XI, ventral view.

Figures 8–9. Goniodes pavonis (Linnaeus, 1758). 8, male abdominal segments IX–XI, dorsal view, showing the inner margin of the ano-genital opening; grey line indicates the approximate outline of the central dorsal plate of abdominal segment IX+X. 9, male abdominal segments IX–XI, dorsal and ventral views, showing the outer surface. Plates and setae shown in Figure 8 are located underneath the central plate of segment IX+X.