Suwannapoom, Dawwrueng & Gorochov & Pawangkhanant & Suwannapoom, 2025

Dawwrueng, Pattarawich, Gorochov, Andrei V., Pawangkhanant, Parinya & Suwannapoom, Chatmongkon, 2025, New data on the genus Megadiestramima Storozhenko & Gorochov, 1992 (Orthoptera: Rhaphidophoridae: Aemodogryllinae), with descriptions of a new subgenus and a new species from Thailand, Zootaxa 5715 (1), pp. 137-142 : 138-140

Subgenus Troglodiestramima Dawwrueng, Gorochov, Pawangkhanant & Suwannapoom , subgen. nov.

Type species: Megadiestramima ( Troglodiestramima) storozhenkoi Dawwrueng, Gorochov, Pawangkhanant & Suwannapoom, sp. nov., designated here.

Diagnosis. Overall appearance similar to other subgenera, but body very large for this genus, especially legs (in both sexes, legs very long compared to body length). Posteromedian process of male seventh abdominal tergite short and widely truncate at apex (similar with that of Megadiestramima s. str.), reaching and slightly covering base of epiproct, but not covering bases of paraprocts ( Figs 1A, B ); posterior margin of this process with row of small denticles which bent downward ( Fig. 1C ); male paraprocts distinctly longer than wide, almost not widened in basal and middle parts, but with distal part gradually narrowing to weakly sclerotized subacute apex ( Figs 1A, B ); male genital plate with trilobed apex (median lobe shorter than lateral lobes; Fig. 1D ); male genitalia with 6 lobes (3 dorsal, 3 ventral) but without sclerites ( Figs 1E, F ). Female very similar to male but with seventh abdominal tergite having distinctly shorter and broadly rounded median process, paraprocts much smaller than in male ( Fig. 2A ); genital plate short and with angular posteromedian part similar to that of Leodiestramima ( Fig. 2B ); ovipositor long, slightly curved upward ( Fig. 2C ), with upper valves having narrow (low) and acute apical parts, and with lower valves having slightly wider (higher) but also acute apical parts as well as shallowed and fined subapical denticles on ventral edge ( Fig. 2D ).

Included species. Only type species.

Comparison. The Troglodiestramima subgen. nov. and Megadiestramima s. str. have similar shape and length of the posteromedian process of the male seventh abdominal tergite, but the new subgenus strongly differs from the latter in the body much larger, the presence of numerous small dark denticles along the posterior edge of the aforementioned process, the shape of the male paraprocts (which are distinctly narrower than in the latter subgenus), the male genitalia without sclerites, and the female genital plate very short and with an angular posteromedian part.

The new subgenus and Leodiestramima are similar in the male genitalia without sclerites and in the shape of the female genital plate, but the new subgenus differs from the latter in a much shorter posteromedian process of the male seventh abdominal tergite having numerous small dark denticles, and in the male paraprocts distinctly narrower and without specialized apical part.

The new subgenus and Neodiestramima are similar in the male genitalia without sclerites, but the new subgenus differs from the latter subgenus in a much shorter and broader posteromedian process of the male seventh abdominal tergite with numerous small dark denticles, the male paraprocts distinctly narrower and without specialized apical process, and the female genital plate very short and with an angular posteromedian part.

Remarks. Parinya Pawangkhanant collected these specimens and discovered their cave-associated behavior. He found the both specimens in a dark zone of a cave in western Thailand. The previously studied specimens of this genus were collected on the forest ground or on the tree trunks (Storozhenko & Gorochov 1992; Gorochov 1998; Gorochov & Storozhenko 2019). We assume that this is the first indication of this genus for caves.

Etymology. The new subgeneric name consists of the Latinized Greek prefix “troglo-” (hole, cave) and the generic name “ Diestramima ” due to the troglophilous (cave-loving) habits of the type species of this subgenus.

Figures

FIGURE 1. Morphological structures of Megadiestramima (Troglodiestramima) storozhenkoi subgen. & sp. nov., male: abdominal apex without lower parts in dorsal view (A) and in lateral view (B); posteromedian process of seventh abdominal tergite in posterior view (C); distal part of genital plate in ventral view (D); genitalia in dorsal view (E) and in ventral view (F).

FIGURE 2. Morphological structures of Megadiestramima (Troglodiestramima) storozhenkoi subgen. & sp. nov., female: abdominal apex without most part of ovipositor in dorsal view (A); genital plate in ventral view (B); ovipositor in lateral view (C); distal parts of ovipositor in lateral view (D).