Pilophorus reoi sp. nov.

Figs.2 H−J, 5, 8, 9

Material examined. Holotype (♂), JAPAN: Ryukyus, Okino-Erabu Island, Kagoshima Pref., China Township, Oyama, 27°21'59"N 128°34'07"E, on Rubus sieboldii, 3 May 2021, R. Ito (NWHS) (AMNH_PBI 00378811) . Paratypes: JAPAN: Ryukyus, same data as for holotype, 1♀ (TYCN); Ryukyus, Amami-Oshima Island, Santarotoge [= current Sumiyo Town, Kamiya, 28.2843, 129.4215], 26 Jul 1954, S. Miyamoto & Y. Hirashima, 1♂ (KUEC) (AMNH_PBI 00380672); Amami-Oshima Island, Shinmura-Yuwan, 28.24, 129.33, 4 Apr 1960, S. Miyamoto, 1♂ (KUEC) (00380673) .

Diagnosis. Recognized by its relatively small size; slender body shape (HCR = 0.77–0.79 in ♂ / 0.74 in ♀); fuscous, clavate antennomere II with reddish basal half; three circularly clustered silvery setae at corners of scutellum; reddish brown anterior hemelytron with clustered silvery setae as in Fig. 2H, J; reddish brown metatibia with creamy yellow extreme base; and relatively narrow, weakly splayed-out left paramere; small apical processes of phallotheca; and narrow-rimmed sclerotized ring.

Description. Macropterous; body generally castaneous or reddish brown, antlike, relatively slender (HCR = 0.77–0.79 in ♂ / 0.74 in ♀); dorsal surface shining, with sparsely distributed, brown simple, reclining setae and scattered clusters of silvery, scale-like setae (Fig. 2H, J). Head shiny chestnut brown, slightly wider than high, narrowly margined along basal vertex; eye small; vertex wider than an eye in dorsal view; head below eyes tinged with red. Antenna dark brown; segment I, basal half of III creamy brown; segment II with reddish brown basal half, clavate, with apical part about as thick as profemur; segments III and IV filiform.Labium shiny reddish brown, slightly exceeding apex of mesocoxa; apical 3/4 of segment III and basal half of segment IV creamy brown. Pronotum shiny fuscous, polished, with uniformly distributed, simple, semierect setae (Fig. 8A, E); scutellum shiny fuscous, with roundly clustered scale-like setae at each angle; pleura dark brown, with clustered scale-like setae on mesepimeron; metathoracic scent efferent system pale brown, with relatively small peritreme (Fig. 8F). Hemelytron almost totally reddish castaneous or maroon, with sparsely distributed, simple, reclining setae, and clustered silvery scale-like setae at subapical clavus, and basal 1/3 and apical 1/3 of corium (Figs. 2H, J, 8A–C); posterior band of scale-like setae interrupted, separated into two clusters; membrane smoky brown, with a narrow, pale, semitransparent part along apical margin of cuneus. Coxae creamy yellow, except for reddish brown mesocoxa; femora reddish brown, with creamy yellow extreme apices (Fig. 2I); all tibiae and tarsi creamy yellow; basal 1/2–2/3 of metatibia dark brown except for pale base; apical part of each tarsomere III more or less darkened; meta-tarsomere III about as long as II (Fig. 8G); pretarsal structure as in Fig. 8H. Abdomen shiny chocolate brown. Male genitalia (Figs. 5A–D, 8I–J): left paramere narrow, not broadly splayed-out (Fig. 5A); apex of phallotheca with small, pointed process (Fig. 5C); vesica nearly J-shaped, with single median process (Fig. 5D). Female genitalia (Figs. 5E–F, 8K–O): sclerotized rings narrow-rimmed (Fig. 5E); vestibular sclerite with thumb-like knob (Fig. 5F); posterior wall as in Fig. 8K–N; interramal lobe with more than 5 rows of spinules along anterior margin (Fig. 8L, N); interramal sclerite with rather densely distributed scaly-microstructures (Fig. 8M).

Measurements. See Table 1.

Etymology. Named after Mr.Reo Ito, who collected valuable specimens and kindly shared biological information of this new species; a noun in the genitive case.

Biology. A pair of adults of this new species were recently collected from a raspberry Rubus sieboldii Blume ( Rosaceae) which appears to be the breeding host (Ito pers. comm.).

Remarks. This new species is assumed to be closest relative of P. pullullus Poppius, 1914 but each species is separable by the characters shown in the below key. Externally, P. reoi sp. nov. is also similar to P. hyotan Yasunaga, Duwal & Nakatani, 2021 (Fig. 2L) and P. typicus Distant, 1909, from which it can be distinguished by the distinctly clavate antennomere II, reddish castaneous brown anterior hemelytron, narrower and not much splayed-out left paramere (Fig. 5A), narrow-rimmed sclerotized ring (Fig. 5E), and more densely distributed spinules on the posterior wall (Fig. 8L, N).

Yasunaga et al. (2021) misidentified two old dry-preserved specimens collected on Amami-Oshima Island (deposited in KUEC) as Pilophorus pullulus Poppius described from Taiwan (cf. Poppius 1914, 1915; National Museum of Natural Science 2025). The present study has verified that the Japanese population occurring on the subtropical islands of the Ryukyus is evidently different from P. pullulus . Accordingly, some relevant couplets (20–22) of the key to Pilophorus species provided by Yasunaga et al. (2021) are revised as follows.

1. Hemelytral clavus fuscous, often posteriorly with silver-grayish pruinosity (Fig. 2L)................................ 2

- Clavus castaneous or reddish brown, without pruinosity (Fig. 2H, J–K)........................................... 3

2. HCR larger (0.66–0.75 in male/ 0.66–0.74 in female); in male, antennal segment II usually greater than twice as long as III and left paramere smaller, weakly expanded left-laterally (cf. Yasunaga et al. 2021, figs. 9L, 15N–O); in female, vertex narrower (≤ 0.39 mm; vertex/head width across eyes = 0.50) and interramal lobe with 2–3 rows of spines along margin (Yasunaga et al. 2021, fig. 16K–L)........................................................................ P. typicus Distant

- HCR smaller (0.62–0.67 in male/ 0.62–0.66 in female); in male, antennal segment II usually twice as long as III and left paramere more strongly expanded left-laterally, spatula-shaped (Yasunaga et al. 2021, figs. 9I, 15G); in female, vertex wider (≥ 0.40 mm; vertex/head width = 0.53–0.57) and interramal lobe with 4–5 rows of spines along margin (Yasunaga et al. 2021, fig. 16N–O).................................................... P. hyotan Yasunaga, Duwal & Nakatani (Fig. 2L)

3. Procoxa almost uniformly brown; cryophilic species currently known only from temperate deciduous forest zone in Honshu........................................................ P. maeharai Yasunaga & Duwal, 2016 (Fig. 2K)

- Procoxa, at least basal half, creamy white (Fig. 2I); thermophilic species occurring subtropical climate zone............. 4

4. Antennomere II uniformly dark brown, almost linear, with apical part less than 1.5 times as thick as base; basal half of metatibia uniformly brown (cf. Yasunaga et al. 2021, fig. 1D–E; National Museum of Natural Science 2025); known only from Taiwan ........................................................................... P. pullulus Poppius

- Antennomere II reddish brown with fuscous apical half, clavate (Figs. 2H–J), with apical part about twice as thick as base (Fig. 8D); basal 1/2–3/5 of metatibia dark reddish brown with creamy yellow annulation at base (Figs. 2H–J); northern Ryukyu Islands (Fig. 9)............................................................................ P. reoi sp. nov.