Diaulota uenoi ( Sawada, 1955 )

Tasaku, Yuto, Ono, Hiroki & Maruyama, Munetoshi, 2023, Review of the intertidal rove beetle tribe Liparocephalini Fenyes (Coleoptera, Staphylinidae, Aleocharinae) from Japan, Zootaxa 5383 (3), pp. 251-296 : 265-268

Diaulota uenoi ( Sawada, 1955)

[Japanese name: Shiributo-umi-hanekakushi]

( Figs. 8 , 9 & 24 )

Genoplectes uenoi Sawada, 1955: 82 (original description; type locality: Nakanoshima (Yoriki)); Sawada, 1971: 106 (redescription).

Diaulota uenoi : Ahn, 1996: 284 (partim, misidentification).

Type material. Holotype. Male, “ Genoplectes / uenoi K. Sawada / 中ノ島, TOKARA Is. / 4 VI ‘52. S. Uéno / (Holotype)” (internal structure of median lobe and sternite VIII lost) (whole body dissected by K. Sawada and mounted by Y. Tasaku) ( OMNH) ( Fig. 9 ).

Other material examined. Japan: Honshû: Wakayama-ken: 1 male, 1 female, Tanabe-shi, Tenjin-zaki , 3. V . 2019, M. Shimono; 1 male, 1 female, Wakayama-shi, Kada-wan , 18. V . 2007, Y. Kawakami ( KUM) ; 1 female, Shirahama-chô, Seto, 29. III . 2006, Y. Nakase ( KUM) ; 4 males, 7 females, Wakayama-shi, Kabuto , 20. V . 2007, S. Fujie ( OMNH) . Kyûshû: Kagoshima-ken: Shiroyama, 13. IV . 1983, M. Ôhara ( KUM) ; 3 males, Ibusuki-shi, Miyaga-hama, 19. IV . 2008, M. Maruyama et al. ( KUM) ; 3 males, 2 females, Minamisatsuma-shi, Kasasa-machi, Ko-ura ( Koura ), 20. IV . 2008, M. Maruyama ( KUM, cYT) ; 2 females, Minamisatsuma-shi, Aiboshi, Aiboshi-gawa , 20. IV . 2008 M, Maruyama et al. ( KUM) . Ryûkyû: Tanega-shima: 1 female, Nishinoomote-shi, Asakawa , 27. III . 2010, M. Asano (cYT).

Diagnosis. It is distinguished from the other species of the genus except D. submarina and D. orientalis sp. n. by the following combination of characteristics: ground color reddish brown, abdominal segments VI and VII black ( Figs. 8A & B ); male head larger than that of female; mentum transverse ( Fig. 8D ); infraorbital carina short, shorter than half of head; tarsal formula 4-4-4. This species very similar to D. submarina and D. orientalis sp. n. and it is very difficult to distinguish by external morphological characters (we call them as the Diaulota uenoi species-complex). Compared to D. submarina , it can be distinguished by the characteristics: apex of apical sclerite rounded in lateral view ( Fig. 8E ); suspensonia broad ( Figs. 8F & G ). Compared to D. orientalis sp. n., it can be distinguished by the following characteristics: apex of median lobe pointed in ventral view; apical sclerite extend toward apical margin in ventral view ( Figs. 8F & G ); spermatheca once coiled around base ( Fig. 8H ).

Remarks. This species, initially described by Sawada (1955) as Genoplectes , was originally based on a single male specimen collected from Nakano-shima, Tokara-rettô, in the northern Ryûkyû. Subsequently, Sawada (1971) undertook a redescription and recorded this species from Wakayama-ken, the southern Honshû. Following these contributions, Ahn (1996) synonymized Genoplectes under Diaulota , extending its known distribution to Korea. Notably, the Korean population was recently described as D. submarina by Ahn (2023). Consequently, its current distribution is exclusively limited to Japan.

In this study, we conducted an extensive examination of numerous specimens collected from Japan, including the holotype. Our findings indicate that D. uenoi is presently confined to the Pacific side of southern Japan, and populations from other regions do not correspond to this species (as detailed below).

When comparing the median lobe of the specimen collected from Nakano-shima ( Fig. 9C ) with those from other regions ( Fig. 8E ), it becomes apparent that the apical lobe of the Nakano-shima specimen is marginally shorter. Nevertheless, the remaining morphological characteristics closely align. Consequently, we have classified them as a single species.

Habitat. This species has been mainly collected from rocky shores. Members of the Diaulota uenoi species-complex exhibit a preference for environments abundant in seaweed; nonetheless, they are occasionally encountered in rocky shores with sparse seaweed presence.

Distribution. Japan: Honshû, Shikoku, Kyûshû (Pacific Ocean side), Ryûkyû (Tanega-shima, Nakano-shima, Tokuno-shima) ( Fig. 24 ).

Figures

FIGURE 8 Diaulota uenoi. A, habitus, male; B, ditto, female; C, labium; D, mentum; E, median lode of aedeagus, lateral view; F, internal structure of median lobe, dorsal view; G, ditto, ventral view; H, spermatheca. Scale bars: 1.0 mm for A, B; 0.1 mm for C–H. Abbreviation: as, apical sclerite; su, suspensonia.

FIGURE 9 Holotype of Diaulota uenoi. A, dissected body parts and label on slide glass; B, labrum; C, median lobe, lateral view. Scale bars: 0.1 mm for A & B.

FIGURE 24 Distribution of Diaulota uenoi (red circle (red ring, type locality)), D. submarina (blue square), and D. orientalis sp. n. (yellow triangle).