Philopterus micropunctatus Gustafsson & Najer & Zou & Bush 2022, sp. nov.

Philopterus micropunctatus sp. nov.

urn:lsid:zoobank.org:act: 2A337930-2324-465E-95D6-8F7EC902C9ED

Figs 7–12; Tables 1–4

Diagnosis

Several species of Philopterus have been described from motacillid hosts; however, few of them are adequately described or illustrated. Złotorzycka & Lucińska (1976) erected the P. passerinus species group based on size, the shape of the trabecula, the shape and chaetotaxy of the male subgenital plate, and the size of the male parameres. They placed Philopterus passerinus (Denny, 1842) (ex Motacilla alba Linnaeus, 1758), P. pavidus (Złotorzycka, 1964) (ex Motacilla flava Linnaeus, 1758), P. vultuosus Złotorzycka, 1964 (ex Anthus trivialis trivialis (Linnaeus, 1758)), and P. hanzaki Balát, 1955 (ex Anthus spinoletta spinoletta (Linnaeus, 1758)) in this group. The other two known species from motacillid hosts, P. irkutensis Fedorenko, 1985 (ex Anthus richardi Vieillot, 1818) and P. subitus Fedorenko, 1985 (ex Motacilla cinerea Tunstall, 1771) may also be closely related to the P. passerinus group, based on the shape of the parameres and trabecula in the original descriptions. However, a complete revision of the Philopterus species on motacillid hosts is sorely needed.

1 One specimen with 7 sternal setae on one side. Segments V–VI with additional, shorter sternal setae lateral to those associated with the sternal plate.

2 Two examined specimens with many sternal setae seemingly absent, and more material is necessary to confirm chaetotaxy of this species.

3 Two of three examined specimens with many sternal setae absent; the numbers mostly derived from single specimen.

4 All examined specimens with 1 medium seta on the left side and none on the right side.

The most distinctive character of P. micropunctatus sp. nov. is the elongated preantennal head and very long dorsal anterior plate (Fig. 9). The fragmented ‘dots’ between the female subvulval plates in P. micropunctatus sp. nov. (Fig. 12) are not found in any other species in the P. passerinus group we have examined. The shape of the head and dorsal anterior plate separates P. micropunctatus sp. nov. from P. irkutensis, P. subitus, P. passerinus, and P. vultuosus. Balát’s (1955) only illustration of P. hanzaki is of the dorsal anterior plate, which is shorter than that of P. micropunctatus sp. nov. and with a differently shaped posterior projection. No illustration of P. pavidus has ever been published, and Eichler’s text description (in Eichler 1953, as Docophorus passerinus Denny, 1842; Złotorzycka’s replacement name P. pavidus was based on this description) does not contain enough detail to separate P. pavidus from any other Philopterus, regardless of host.

Etymology

The species name is derived from the Greek ‘ mikro ’ for ‘small’ and the Latin ‘ punctatus ’ for ‘dotted’, referring to the many small dots median to the subvulval plates. 1 Segments V–VI with additional, shorter sternal setae lateral to those associated with the sternal plate; on segment IV of single examined male these are closer to the pleural setae, and these setae are therefore here included in the count of pleural setae on all segments.

Material examined

Holotype THAILAND • ♂; Nan Province, Bun Yun, Pang Nam Un; 21 Jan. 1953; R.E. Elbel and H.G. Deignan leg.; ex Anthus hodgsoni; “ RE-2103, RT-B-17720 ”; NHMUK.

Paratypes THAILAND • 1 ♀; same collection data as for holotype; NHMUK • 3 ♀♀; same collection data as for holotype; PIPR.

Type host

Anthus hodgsoni Richmond, 1907 – olive-backed pipit (Motacillidae).

Description

Head shape and chaetotaxy as in Fig. 9, preantennal area moderately broad. Hyaline margin wide, slightly concave medianly, not extending much lateral to marginal carina. Dorsal preantennal plate long, narrowing gently posteriorly, with distinct lateral thickenings along much of lateral margins anterior to ads. Ventral anterior plate bluntly crescent-shaped. Coni small, pointed posteriorly. Thoracic and abdominal segments as in Figs 7–8. Measurements as in Table 1.

Male Thoracic and abdominal chaetotaxy as in Fig. 7 and Tables 2–4. Central sternal plates absent on segments II–VI. Lateral accessory plates present on segments III–VI. Subgenital plate broad, but diffuse distally and illustrated approximately. Basal apodeme short and slender (Figs 10–11). Mesosomal thickening

truncated oval; mesosome with 3 microsetae on each side (Fig. 10). Gonopore bluntly lanceolate, with wide, roughly triangular sclerotization anterior and lateral to opening, proximally fused to basal apodeme; 2 sensilla on each side of gonopore. Parameres short and stocky (Figs 10–11); pst1–2 as in Fig. 10.

Female

Thoracic and abdominal chaetotaxy as in Fig. 8 and Tables 2–4. Central sternal plates absent on segments II–VI. Lateral accessory plates present on segments III–VI. Subgenital plate as in Fig. 12; lateral sclerotizations of vulval area extended posteriorly to approach vulval margin; in one female also extended anteriorly to fuse with subgenital plate. Vulval margin more or less straight, chaetotaxy as in Fig. 12 and Table 3. Subvulval plates slender distally, with many small fragmentary dots between plates as in Fig. 12.