Tisamenus makinis, Hennemann, 2025

Tisamenus makinis View in CoL n. sp.

( Fig. 31)

ZooBank:https://zoobank.org/ 225C1EEB-F9E8-469B-AE0F-C08C2875939D

HT, ♂: Coll.R.I.Sc.N.B., Philippines, E. Luzon, Isabela, Didin , IX.2014, local collector, I. Lumawig [ RBINS] .

Differentiation. – The ♂ of this new species (the only sex known) is easily recognised by the wholly reduced body armature, which readily separates it from all other congenerics. Moreover, it is remarkable for also having the leg armature almost completely reduced and the triangular mesonotal area notably raised but with its outer carinae very weakly developed, shallow and hardly discernible. The reduced body armature is shared with T.kalahani Lit & Eusebio, 2005 from Nueva Vizcaya province, but the present species differs by the much stockier overallshape and lacking the large anterior pronotals seen in kalahani as well as having the carinae of the triangular mesonotal area much less obvious.

Etymology. – The name ( makinis Filipino = smooth) refers to the remarkably reduced body armature of this slender and smooth species.

Description

♂ ( Fig. 31)

Form and colouration. – Size small (body length 30.8 mm); general form relatively slender and elongate, legs slender; cephalic armature weakly developed ( Fig. 31D) and body armature almost wholly reduced. Meso- and metathorax gradually widening towards posterior andtogether forming a sub-trapeziform unit; body surface minutely and unevenly coriaceous, rugulose or shallowly granular; dorsal keels of thorax, thoracic sterna and the limbs unusually setose. General colour uniformly fuscous, the tarsi faintly orangey. Antennae except for scapus and pedicellus missing in the unique holotype.

Head. – Rectangular, a little longer than wide with the genae parallel-sided. Supra-orbitals small, conical and tubercular; occipitals sub-obsolete and coronals very low, rounded tuberculate; gulars practically missing ( Fig. 31D). Frons with a shallow bilobate swelling between the eyes. Eyes of average size, slightly oval in outline, moderately globose and their diameter corresponding to scarcely less than half the length of gena. Scapus elongate, triangular and notably narrowing towards base; pedicellus less than half as long, round in cross-section and somewhat constricting towards apex.

Thorax. – Pronotum slightly sub-trapeziform; triangular area very faintly indicated, anterior pronotals merely represented as low nodes close to anterior margin; transverse median sulcus distinctly indented and almost straight ( Fig. 31D). Mesothorax distinctly gradually widening towards posterior, about 2x longer than prothorax and with posterior portion 1.5x wider than anterior margin. Mesonotum elongate, trapezoidal with lateral margins distinctly convergent towards the posterior andwitha gentle narrowingpre-posteriorly; about 2.1x longer than width at anterior margin and the anterior margin 1.3x wider than posterior margin. Triangular area strongly raised, very large and covering almost three-quarter of the length of notum, elongate and>2x longer than width across anterolateral angles; disk very shallowly concave and the straight, converging outer margins densely setose ( Fig. 31D). Posterior portion of mesonotum with a bold, setose medio-longitudinal bulge, that is very faintlyindicated in the posterior half of triangular area. Mesopleurae gradually expanding towards the posterior and unarmed with only the mesopleural weakly indicated as a small, slightly conical node. Metanotum notably longer than wide with a distinct pre-medial narrowing in the anterolateral portions distinctly indented; the medio-longitudinal bulge prominent, setose and shallowly granular. Metapleurae gradually widening with the same angle as mesopleurae; laterals sub-obsolete and only represented by about four low nodes;themetapleuralsomewhat more pronounced and the supra-coxal angle just very weakly protruded. Prosternal sensory-areas weakly developed. Meso- and metasternum weakly and shallowly carinate medio-longitudinally ( Fig. 31E).

Abdomen. – Median segment trapezoidal, transverse, obtuse carinate medio-longitudinally and with very small nodose pair of second paired posteriors. Entire dorsal surface of abdomen with an obtuse are comparatively distinct medio-longitudinal carina. Segment II trapezoidal; II-VII slightly sub-uniform in width and somewhat decreasing in length, all slightly transverse with VIII almost 2x wider than long. II-VI very gently narrowing and V-VII slightly decreasing in length; II sub-trapeziform, IV roughly quadrate and VI-VII slightly transverse. Terga II-VII all with a slight median narrowing. Sterna II-V with a rather broad but low and obtuse medio-longitudinal carina ( Fig. 31C). Terga VIII and IX distinctly transverse with the medio-longitudinal keel posteriorly terminating in a shallow nodose swelling ( Fig. 31F) and with the posterolateral angles somewhat protruded and digitiform ( Fig. 31G). Anal segment longer than IX, slightly declining, keeled medio-longitudinally and somewhat narrowed posteriorly, the lateral margins angular and notably protruded at the angle; posterior margin with a wide, but distinct concave emargination and the outer angles obtusely protruded ( Fig. 31G). Epiproct slightly transverse, rounded, shield-shaped and slightly projecting beyond posterolateral protrusions of anal segment ( Fig. 31G). Vomer broadly triangular, Fig. 30. Tisamenus lachesis ( Rehn & Rehn, 1939) Live insects. A. Mating couple [© Gernot Kunz: https://inaturalist.ca/observations/ 24796645]. B. Captive reared ♀ from Real, Sierra Madre, Quezon Province, Luzon. C. Closeup of head and thorax of captive reared ♂ from Real, Sierra Madre, Quezon Province, Luzon. D. Captive reared ♂ from Real, Sierra Madre, Quezon Province, Luzon.

almost symmetrical with the terminal hook up-curved by almost 90°; ventral surface shallowly concave in centre ( Fig. 31H). Poculum moderately bulgy, roundly cup-shaped with posterior margin narrowed, bi-lobed and with a shallow median indention ( Fig. 31H).

Legs. – Long and slender for the genus with armature much reduced; the tibiae very weakly carinate and wholly unarmed. Pro- and mesofemora slightly shorter than mesothorax, metafemora reaching about halfway along abdominal segment V and metatibiae roughly reaching to tip of abdomen. Pro- and mesofemora dorsally only with two very shallow swellings in basal half and the two ventral carinae merely with two faintly indicated teeth in apical one-third. Metafemora without a ventro-basal swelling; the dorsal carinae only with four very faint swellings and the two ventral carinae with two weakly indicated and obtuse teeth in basal half and two more decided small, blunt teeth in apical half. Basitarsi very short and just slightly longer than following tarsomere.

Measurements of holotype [mm]. – Body 30.8, pronotum 2.8, mesonotum 6.3,metanotum 3.3, mediansegment1.7, profemora6.1,mesofemora 5.5, metafemora7.2,protibiae 5.8, mesotibiae 4.9,metatibiae 6.1, antennae> 2.0.

Remarks. – Female and egg unknown.

Distribution. – EastLuzon,endemic (Province Isabela,Didin[RBINS – type locality]).