Tisamenus armadillo Redtenbacher, 1906

Hennemann, Frank H., 2025, A taxonomic review of Philippine Obrimini stick insects: The genus Tisamenus Stål, 1875 (Insecta: Phasmatodea: Heteropterygidae: Obriminae), Faunitaxys 13 (24), pp. 1-85 : 13-15

Tisamenus armadillo Redtenbacher, 1906

( Fig. 4, 46 A-B)

Tisamenus armadillo Redtenbacher, 1906: 44 , pl. 1: 8 (♀).

LT, ♀ (+ 1 egg ex ovipositor): Philippinen, Schadenberg ; 694 [ SMTD] ;

PLT, ♀: Philippinen, Schadenberg ; 694 [ SMTD] .

- Bruner, 1915: 230.

- Zompro, 2003: 33. (Type data)

- Zompro, 2004: 206. [Not: Figs. 117a-b. Misidentification relating to T. deplanatus ( Westwood, 1848) ]

- Otte & Brock, 2005: 334.

- Brock & Büscher, 2022: 521.

- Hennemann, 2023b: 128.

Hoploclonia armadillo, Rehn & Rehn, 1939: 477 . (Deplanata Group) - Zompro, 2001: 50, figs.

Material examined

1 ♂: Philippinen, Schadenberg ; 694 [ SMTD] .

Differentiation. – Both sexes of this rarely known species are morphologically very similar to T. cervicornis Bolívar, 1890 from South Luzon and Samar and T. deplanatus ( Westwood, 1848) from Northern Luzon but are smaller and have all the elements of cephalic and body armature somewhat less pronounced and more obtuse.This includesobtusely conicalsupa-orbitals ( Fig.4F),which are tuberculate to spinose in cervicornis and deplanatus and obtuse compound anterior pronotals, which are basically trifid ( Fig. 4F; spinose and more or less clearly bifid in cervicornis and deplanatus ). From deplanatus both sexes additionally differ by the shorter and broader mesonotal triangular area, which isno longer than itis wide across the anterolateral angles, and less medially indented anterior margin of the mesonotum. Males have the emargination of the posterior margin of the anal segment more angular than in deplanatus ( Fig. 4G), the posterior margin of the poculum is less labiate and less distinctly down-curved, the posteromedian swelling of the meso- and metanotum is less pronounced and lacks the small pair of nodular inter-posteriors seen in deplanatus ( Fig. 4E) and the disc of the mesonotal triangular area is rather concave and lacks a medio-longitudinal carina. Already Redtenbacher (1906: 449) pointed to the affinity to deplanatus , but examination of the type-specimens of armadillo has shown the distinguishing features that Redtenbacher mentioned, namely the simplicity of the very strong metapleural supra-coxal and the presence of a pair of spines on the basal abdominal terga, do not hold true for separation of this species from deplanatus (and cervicornis ). The shape of the metapleural supra-coxal is variable in deplanatus and inboth known ♀ of armadillo itis accompanied by a smaller spine, and abdominal terga II-V also bear second paired posterior spines in deplanatus . Males are also particularly similar to T.tagalog ( Rehn & Rehn, 1939) and can merely be distinguished by the somewhat smaller bifid anterior pronotal spines, mesopleural and supra-coxals of the metapleurae, less spinose supra-orbital,slightly concave carinae of the triangular mesonotal area that have the anterior angle triangularly protruded (rather convex with the anterior angle only weakly raised in tagalog ), larger epiproct that extends notably beyond the posterolateral angles of the anal segment ( Fig. 4G), angular and bulgy poculum ( Fig.4J; much flatter and rather scoop-shaped in armadillo ) and less prominent spines of the posterodorsal carina of the metafemora. The egg ( Fig. 46 A-B) is closest to that of deplanatus but may be distinguished by the more distinctly constricted anterior margin of the capsule and comparatively broader micropylar plate, which has the anterior end in particular broader and less narrowed with the lateral margins of the anterior extension of the plate almost parallel-sided (converging towards a narrow apex in deplanatus ). Although armadillo is morphologically closest to cervicornis the eggs are readily separated by the bulgier shape, distinctly constricted anterior margin and lack of the net-like sculpturing of the capsule, considerably larger micropylar plate and lacking the distinct rim of fringes seen on the operculum of cervicornis .

Description

♂ ( Fig. 4 D-E)

Form and colouration. – Size average for the genus (body length 36.0 mm); general form rather stocky, legs fairly strong but not incrassate; elements of armature weakly developed. General colour dark russet, the meso- and metasternum tawny. Antennae orangey brown with the terminal twelve joints ochre.

Head. – Sub-quadrate, scarcely longer than wide with the genae roughly parallel-sided. The three supra-orbitals moderately prominent, conical with the median one largest;occipitals small, rounded and the median and lateral coronals tuberculate and somewhat larger than occipitals. Eyes small, globose and their diameter corresponding to about 0.4x length of gena. Antennae consisting of 26 joints; scapus triangular in dorsal aspect, pedicellus about half the length of scapus and barrel-shaped; III slightly longer than pedicellus, IV much shorter and up to XI slightly increasing in length, then decreasing with the terminal antennomere much elongated and almost as long as three preceding joints taken together.

Thorax. – Pronotum sub-quadrate; triangular area weakly indicated with margins obtusely granular and the anterolateral angles with a strong and conical bifid tubercle ( Fig. 4E); transverse median sulcus distinctly indented. Mesothorax slightly widening towards posterior and about 2.1x longer than prothorax. Mesonotum sub-trapeziform with lateral margins slightly convergent towards the posterior and about 2x longer than width at anterior margin; the triangular area rather small, not attaining middle of notum, faintly longer than wide, disk shallowly concave and the weakly concave outer margins anteriorly protruded into an obtuse tubercle; posterior portion of mesonotum with a minutely but densely granulose medio-longitudinal keel. Mesopleurae slightly expanding towards the posterior with laterals merely represented by low rounded tubercles; mesopleural a rather small and simple conical tubercle. Metanotum trapezoidal, scarcely longer than wide and with the same granulose medio-longitudinalkeelseen in mesonotum. Metapleurae with laterals sub-obsolete, the metapleural somewhat more pronounced and the supra-coxal angle with a strong but short simple supra-coxal spine ( Fig. 4D). Mesosternum tri-carinate with the lateral carinae weaker; metasternum with a shallow medio-longitudinal carina.

Abdomen. – Median segment almost semi-circular in outline, carinate medio-longitudinally and with a small tubercular pair of second paired posteriors. Segments II-VII sub-uniform in length and width, all slightly wider than long;II-V with tuberculate paired second posteriors (very small although on V) and all terga with a fine but fairly acute medio-longitudinal carina which posteriorly terminates in a low tubercle on II-VII; on VI and IX the carina is increasingly elevated and posteriorly protruded into a rather conical swelling. Basal sterna with an indicated medio-longitudinal carina. Anal segment strongly declining and somewhat narrowed posteriorly with the lateral margins angular and the dorsal surface with an obtuse medio-longitudinal carina; posterior margin with a shallow, rounded median excavation and the outer angles obtusely protruded. Epiproct transverse, roundly rectangular and notably projecting beyond anal segment ( Fig. 4G). Poculum angularly cup-shaped with a broad and labiate posterior flange, that is slightly down-curved and reaches about halfway along anal segment ( Fig. 4J).

Legs. – Moderatelystockywiththefemoral teethfairlydistinctandacutely triangular; the dorsal ones of the metafemora decreasing in size towards apex of femur and the three terminal teeth on ventral carinae strong, spinose and roughly uniform in size. Pro- and mesofemora somewhat shorter than mesothorax,

A. ♀ PLT dorsal view. B. ♀ PLT lateral view. C. ♀ LT lateral view. D. ♂ dorsal view. E. ♂ lateral view. F. Closeup of head and thorax of ♀ LT in dorsolateral view. G. Terminalia of ♂ in dorsal view. H. Terminalia of ♀ LT in dorsal view. I. Terminalia of ♀ LT in lateral view. J. Terminalia of ♂ in lateral view.

metafemora reaching one-third along abdominal segment VI and metatibiae projectingbeyond tip of abdomenbyabout thecombinedlength of twoterminal terga. Ventro-basal swelling of metafemora distinct, sub-globose. Metatibiae smooth dorsally and with 3-4 small teeth ventrally. Basitarsi almost as long as following three tarsomeres taken together.

Measurements [mm]. – Body 36.0, pronotum 4.2, mesonotum 7.7, metanotum 4.1, median segment 2.2, profemora 8.5, mesofemora 6.9, metafemora 9.3, protibiae 7.2, mesotibiae 6.6, metatibiae 9.7, antennae ca. 15.0.

Egg ( Fig. 46 A-B)

Of moderate size for the genus; capsule barrel-shaped and bulgy with a distinct and broad constriction of the anterior portion and a very scarcely flattened polar-area, oval in cross-section and notably higher than wide; the capsule 1.5x longer than wide. Entire surface minutely pitted and with irregularlydispersed byfairlysparseclustersof small, fringyexcrescences that are most numerous in the polar region and below the anterior constriction of the capsule. Micropylar plate very large and almost 0.85x as long as capsule; clearly Y-shaped with the median portion fairly slender, almost uniform in width and reachingto the lowermargin of the anterior constrictionof capsule; the two posterolateral extensionsslightly widerin the medianportion with the apex somewhat narrowed and on lateral surfaces slightlyprojecting over axis of egg capsule; the posterior portion 90° V-shaped with a small bowl-shaped micropylar cup incentre.Outer margin markedby a fairlynarrow and shallow ridge, the interior portion somewhat raised and essentially sculptured like capsule; the area in between forming a slightly indented rim that is destitute of any notable sculpturing. Median line an indistinct slender carina that almost reaches to the polar area. Operculum slightly elliptical and flattened with only a shallow collar of fringy protuberances at outer margin and a broad ring of similar protuberances interiorly, the central area indented with a small central protuberance. Colour mid brown with the constricted anterior portion of capsule, outer margin of micropylar plate and operculum dark brown. Measurements [mm]: Length incl. operculum 3.6, length 3.6, width 2.4, height 2.8, length of micropylar plate 3.0.

Remarks. – Redtenbacher (1906: 44) described T. armadillo from two ♀ in the collection of SMTD.A lectotype ( Fig. 4C) was selected by Zompro (2003: 33), who extracted an egg from the ovipositor of the specimen ( Fig. 46 A-B). The additional ♂ in the collection of SMTD is apparently conspecific to the two ♀ types but cannot be regarded part of the type series because Redtenbacher (1906: 44) did not mention any ♂ in the original description ( Fig. 4 D-E). Descriptions and illustrations of the previously unknown ♂ and egg are presented herein based on this specimen. Unfortunately, there is no definite information as to the exact locality in the Philippines from which came rarely known species was collected. Zompro (2004: 206, Fig. 117a-b) recorded armadillo based on a ♂ and ♀ from the Ilocos Region of Northwest Luzon in the collection of SMTD, but these two specimens actually represent T. deplanatus ( Westwood, 1848) . Body length of ♀ 48.0 mm.

Distribution. – Philippines [SMTD – type locality].