Tisamenus deplanatus ( Westwood, 1848 )

Tisamenus deplanatus ( Westwood, 1848) View in CoL

( Fig. 14-16, 46 I-J)

Phasma (Pachymorpha) deplanatum Westwood, 1848: 78 , pl. 38: 6 ( ♀).

HT, ♀: Phil. Isla., 42 22; Phasma (Pachymorpha) deplanatum Westw.

Orient. Ent. t 38 f 6; Holotype; BMNH(E) #845220 [NHMUK].

Acanthoderus deplanatus, Westwood, 1859: 52 .

Tisamenus deplanatus, Stål, 1875: 93 View in CoL .

- Kirby, 1904: 399.

- Redtenbacher, 1906: 44.

- Bruner, 1915: 229.

- Harman, 2022: 24.

- Brock & Büscher, 2022: 521, fig.

- Hennemann, 2023b: 128.

Tisamenus deplanata, Zompro, 2004: 206 .

- Otte & Brock, 2005: 334.

- Brock et al., 2016: 168. (Type data) A. Dorsal view [ FH 0904-6 ]. B. Dorsolateral view [ FH 0904-6 ]. C. Lateral view [ FH 0904-6 ]. D. Ventral view [ FH 0904-6 ]. E. Holotype, lateral view [ NHMUK © Paul D. Brock]. F. Terminalia in lateral view. G. Terminalia in dorsal view. H. Terminalia in ventral view. I: Closeup of head, pro- and mesonotum [ FH 0904-6 ]. J. Closeup of pro-, meso- and metasternum [ FH 0904-6 ].

Tisamenus armadillo, Zompro, 2004: 206 View in CoL , figs. 117a-b (in part – only the illustrated specimens from Ilocos, Luzon).

[ Not: Hoploclonia deplanata, Rehn & Rehn, 1939: 477 , pl. 35: 34 ( ♀). ( Deplanata Group). Misidentification relating to T. cervicornis Bolívar, 1890 ]

[ Not: Tisamenus deplanata, Dräger, 2012: 14 , figs. 23-25. Misidentification relating to T.cervicornis Bolívar, 1890 ]

Material examined

2 ♀, 1 ♂: Coll. R.I.Sc. N.B., Philippines, N-Luzon, Ilocos , III.2014, leg. T. Heitzmann [ RBINS] ;

2 ♀, 2 ♂: Coll. R.I.Sc.N.B., Philippines, Luzon, Ilocos, ex breeding Sven Bradler 2019, Phasmid Study Group #391 [ RBINS] ;

1 ♂: Coll. R.I.Sc.N.B., Philippines, N-Luzon, Ilocos [ RBINS] ;

1 ♀, 1 ♂: Luzon, Ilocos N., Burgos, coll. W. Schultze [ SMTD] ;

18 ♀ 10 ♂ eggs: ex Zucht F. Hennemann 2016 -2017, Herkunft: Philippinen, N-Luzon, Prov., Ilocos Norte, leg. T. Heitzmann 2014 [ FH, No’s 0904-1 to 28, E] .

Differentiation. – This species is morphologically closest to T. cervicornis Bolívar, 1890 and T. asper Bolívar, 1890 . From cervicornis both sexes can readily be separated by the notably larger mesonotal triangular area ( Fig. 14I, 15I), which attains the middle of the mesonotum and is longer than it is wide across the anterolateral angles. Males are also easily distinguished by having the meso- and metanotum gibbous and bi-nodose pre-posteriorly ( Fig. 15C) and the terminal hook of the vomer backward-directed (arched towards the left in cervicornis ) and ♀ are distinguished by the characteristically convex and gibbous epiproct ( Fig. 14F). Moreover, both sexes are on average larger and slightly less stocky in shape than cervicornis . The more rounded and bulgy eggs ( Fig. 46 I-J) are well differentiated from those of cervicornis by having the capsule surface much less sculptured and only covered with a faintly raised network of ridges, and the micropylar plate being almost as long as the capsule with the anterior extension noticeably longer than the posterolateral extensions. With asper this species shares the fairly large mesonotal triangular area that is longer than wide across the anterolateral angles and slightly surpasses the middle of the mesonotum, but in deplanatus the carinae are much more pronounced and triangularly protruded anteriorly. Moreover, both sexes of this species are stockier in shape, lack the four mesopleural laterals seen in asper (six tuberculate mesopleurals in total in asper ) and have prominent bi-spinose anterior pronotals ( Fig. 14I, 15I) as well as distinct second paired posterior spines on abdominal terga II-III (or II-IV), both elements of which are poorly developed and obtuse in asper .

Description

♂ ( Fig. 15)

Form and colouration. – Size average for the genus (body length 38.3-43.0mm);generalform relatively slender, legs fairly strong with only the metafemora incrassate; elements of armature rather weakly developed. Mesothorax strongly widening towards posterior, meso- and metanotum with a distinct, bi-tuberculate, gibbose posteromedian swelling and body surface minutely and unevenly granular and nodose. General colour dark buff to brown, the meso- and metasternum tawny and the meso- and metafemora with a sub-apical tawny transverse band ventrally ( Fig. 15D). Antennae orangey brown with only the terminal joint ochre.

Head. – Sub-quadrate, a little longer than wide with the genae roughly parallel-sided. The four supra-orbitals moderately prominent, conical with the second one largest (occasionally compound); occipitals and coronals rather low, rounded tuberculate ( Fig. 15I). Gulars small and nodose. Eyes of average size, moderately globose and their diameter corresponding to scarcely less than half the length of gena. Antennae consisting of 27 joints ( Fig. 15I); scapus triangular in dorsal aspect, pedicellus about half as long as scapus, round in cross-section and somewhat narrowing towards apex; III about as long as pedicellus, IV only one-quarter the length of III, following joints up to about XVIII very slightly increasing in length, then decreasing with the terminal antennomere notably elongated and almost as long as three preceding joints taken together.

Thorax. – Pronotum sub-trapeziform; triangular area fairly distinct with margins minutely tubercular and the anterolateral angles with a strong and prominent, conical bifid tubercle ( Fig. 15I); transverse median sulcus distinctly indented and almost straight. Mesothorax distinctly widening towards posterior, about 2x longer than prothorax and with posterior portion 1.45x wider than anterior margin. Mesonotum elongate with lateral margins weakly convergent towards the posterior and with a distinct concave postmedialconstriction;about 2.1x longer thanwidthat anterior margin and witha gibbose posteromedian swelling that bears a pair of low, closely spaced inter-posterior tubercles ( Fig. 15C); the triangular area rather large, somewhat surpassing middle of notum,notablylonger than wide, diskshallowly concave and the straight, converging outer margins densely granular and anteriorly protruded into a fairly prominent, conical, somewhat posterior directed tubercle; posterior portion of mesonotum with a minutely but densely granulose medio-longitudinal bulge, that is clearly visible in the posterior half of triangular area ( Fig. 15I). Mesopleurae strongly expanding towards the posterior with the five laterals merely represented by low rounded nodes; mesopleural a rather small and simple conical tubercle. Metanotum distinctly trapezoidal in outline, a little longer than wide and with the same granulose medio-longitudinal bulge and bi-tuberculate, gibbose posterior swelling seen on mesonotum. Metapleurae with laterals sub-obsolete, the metapleural somewhat more pronounced and the supra-coxal angle with a strong but short supra-coxal tubercle that is accompanied by a much smaller tubercle posteriorly. Mesosternum distinctly tri-carinate with the lateral carinae arched and converging in posterior portion ( Fig. 15J); metasternum only with a rather shallow medio-longitudinal carina.

Abdomen. – Median segment almost semi-circular in outline, carinate medio-longitudinally and with a small node-like pair of first and second paired posteriors. Segments II-VII slightly sub-uniform in length and width, 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 shallow medio-longitudinal carina that is indicated by two parallel rows of slightly pronounced granules; II-IV with paired second posteriors, that are spinose on II, tubercular on III and merely nodose on IV. The medio-longitudinal carina posteriorly terminating in a tubercular swelling that is most prominent on IX. Sterna II-VII with a fine medio-longitudinal carina ( Fig. 15D). Anal segment moderately declining and somewhat narrowing towards the posteriorly with the lateral margins angular and the dorsal surface with an obtuse medio-longitudinal carina; posterior margin with a wide, roundly angular median emargination and the outer angles obtusely triangularly protruded ( Fig. 15G). Epiproct transverse, roundly trapeziform with a shallow posteromedian indention and slightly projecting beyond posterolateral protrusions of anal segment ( Fig. 15G). Vomer broadly heart-shaped with the short but strong and up-curved terminal hook distinctly arched towards the left. Poculum angularly cup-shaped with a very broad and labiate posterior flange of the free upper margin, that is distinctly down-curved ( Fig. 15F) and shallowly emarginated posteriorly ( Fig. 15H) and reaches about halfway along anal segment.

Legs. – Moderatelystockywith the femoralteeth fairly distinctandacutely 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 noticeably shorter than mesothorax, metafemora reaching one-third along abdominal segment V and metatibiae roughly reaching to tip of abdomen. Pro- and mesofemora with only the twoapical teeth of outer ventral carinae distinct; these teeth also quite pronounced on metafemora, which have the four dorsal teeth small and somewhat increasing in size towards the base of femur. Ventro-basal swelling of metafemora distinct, sub-globose and smooth ( Fig. 15E). Metatibiae smooth dorsally and with 5-6 small obtusely triangular teeth on two outer ventral carinae ( Fig. 15E). Basitarsi short and just slightly longer than following two tarsomeres taken together.

Measurements [mm]. – Body 38.3–43.0, pronotum 3.8-4.0, mesonotum 7.2-7.5, metanotum 3.8-4.4, median segment 2.1-2.5, profemora 7.7-7.9, mesofemora 6.3-6.5, metafemora 8.9-9.9, protibiae 7.0-8.1, mesotibiae 6.2-6.9, metatibiae 8.0-9.0, antennae 12.0–13.0.

A. Dorsal view. B. Dorsolateral view. C. Lateral view (arrows highlighting the gibbous and bi-nodose posteromedian swelling of the meso- and metanotum, which readily distinguishes T. deplanatus from the morphologically closest species). D. Ventral view. E. Anteroventral view of right hind leg. F. Terminalia in lateral view. G. Terminalia in dorsal view. H. Terminalia in ventral view. I: Closeup of head, pro- and mesonotum. J. Closeup of pro-, meso- and metasternum.

Variability. – The range of morphological variability among the fairly numerous examples at hand for examination is small and noteworthy variation is only seen in the size of the cephalic, thoracic and abdominal elements of armature and relative size of the mesonotal triangular area. Some examples of both sexes show a small interjacent point between the two spikes of the basically bifid pronotal anteriors, which may however only be present on one side. Body length of ♀ 56.0-67.0 mm.

Egg ( Fig. 46 I-J)

Fairly large for the genus; capsule roundly oval with a broad constriction of the anterior portion, the dorsal surface strongly bulgy and much more convex than the ventral surface, which is only somewhat bulgier in the lower portion; oval in cross-section and notably higher than wide; the capsule almost 1.6x longer than wide. Surface very minutely and densely granular and with a rather uneven and coarsely meshed network of granular ridges, which are most distinctly protruded and occasionally tuberculiform at their junctures. Micropylar plate very large and almost as long as capsule; narrowly Y-shaped with the median portion fairly uniform in width and approaching the anterior margin of capsule and the two posterolateral extensions slightly narrower and on lateral surfaces of capsule roughly reaching to axis of egg; the posterior portion 80° V-shaped with a small bowl-shaped micropylar cup in centre. Outer margin of plate notably inflated and granular, the interior portion distinctly raised and unevenly rugulose and the rim in between indented and destitute of any protrusions or notable sculpturing. Median line almost indiscernible and only marked by a short and shallow carina. Operculum almost circular with an obtusely inflated outer collar; the interior portion somewhat convex, unevenly tubercular and with a distinct impression in centre. Colour mostly buff with the constricted anterior portion of the capsule greyish brown; micropylar cup dark brown. Measurements [mm]: Length incl. operculum 3.8, length 3.8, width 2.4, height 2.8, length of micropylar plate 3.2.

Remarks. – Originally described upon a unique ♀ holotype in the collection of NHMUK by Westwood (1848: 78), there was only one further record of deplanata in the literature. This record from Surigao, N-Mindanao by Rehn & Rehn (1939: 477) is based on a misidentified (see remarks on T.cervicornis Bolívar, 1890 ).

Culture stock of this species has originally been collected in March 2014 by Thierry Heitzmann ( Philippines) in Ilocos Norte and eggs have been sent to Europe for breeding purposes. The culture maintained since has been given culture No. 391 by the Phasmid Study Group and was distributed as Tisamenus sp. ‘Ilocos’ or erroneously as Tisamenus fratercula ‘Ilocos’. The true identity of the stock of PSG 391 is here clarified. The latter species is here synonymised under T.cervicornis Bolívar,1890 ( n. syn.). This species as well has proven pretty easy to breed in captivity.

The ♂ and egg are here formally described for the first time and illustrated.

Distribution. – Philippines [NHMUK – type locality].N-Luzon: Province IlocosNorte [RBINS,FH];IlocosNorte,Pagudpod [photographic records by Albert Kang: https://inaturalist.ca/observations/57634024, https:// inaturalist.ca/observations/57610502]; Ilocos Region [SMTD].