Theramenes Stål, 1875

Genus Theramenes Stål, 1875 View in CoL

Type -species. – Eurycantha olivacea Westwood, 1859: 65 , by monotypy.

Theramenes Stål, 1875: 46 View in CoL .

Stål, 1877: 68.

Kirby, 1904: 399.

Redtenbacher, 1906: 36.

Rehn & Rehn, 1939: 412.

Bradley & Galil, 1977: 199.

Bragg, 2001: 644.

Zompro, 2004: 209, 322. (Tribe Eubulidini ).

Otte & Brock, 2005: 332.

Bollens, Krijns & Bresseel, 2010: 23.

Hennemann, Conle, Brock & Seow-Choen, 2016: 18. (Tribe Obrimini , Theramenes -group).

Brock & Büscher, 2022: 521.

Eurycantha, Westwood, 1859: 65 View in CoL , pl. 2: 8.

Reviewer:

Differentiation. – This very characteristic genus is well characterised by the specialization of the thoracic armature and strongly incrassate metafemora of ♂, which readily distinguish it from all other representatives of the entire subfamily. The prominent hump or wart-like posteromedian swelling of the meso- and metanotum are unique within the Obriminae , as are the strikingly unequal abdominal segments of the ♂ of certain species. Females have these posteromedian meso- and metanotal swellings much less distinct to almost wanting but are characteristic for being the plumpest and stockiest of all Obriminae with the abdominal segments more than 3x wider than long.

Remarks. – Stål (1875) originally established this very distinctive genus for a species described in the Papuan genus Eurycantha Boisduval, 1835 ( Lonchodidae : Eurycanthinae ) and originating from the Talaud Islands by Westwood (1859) and described a second Philippine species subsequently ( Stål, 1877). A third Philippine species was described from the island of Cebu by Zompro & Eusebio (2001) and a fourth Philippine species from the island of Panay by Hennemann & Conle (2003). Hennemann et al. (2016: 19) have clarified the erroneous synonymy of Theramenes dromedarius Stål, 1877 under the type-species T. olivaceus ( Westwood, 1859) introduced by Günther (1934: 75) and have re-established this distinctive species. The description of a new species from the island of Mindanao closes the distributional gap between the more northern VisayasIslandsgroupandtheTalaudIslandsinthesouth.

Zompro (2004) included Theramenes in the tribe Eubulidini together with seven other genera. Hennemann et al. (2016:18) have shown that there was no morphological support for a separation of Eubulidini as a distinct tribe and grouped the genus together with Eubulides Stål, 1877 , Heterocopus Redtenbacher,1906 and Mearnsiana Rehn & Rehn, 1939 in the Theramenes -group of the tribe Obrimini .This generic group was characterized among Obrimini by the increasing simplicity of the body armature, lack of posterior mesonotal and metanotal spines, flattened and weakly armed to unarmed head as well as the increasingly thickened metafemora of ♂ in particular.Moreover, Hennemann et al. (2016) presumed close relation to Eubulides and Heterocopus in particular because these three genera share are strongly up-curved ovipositor in ♀.In a molecular analysis of the Obriminae by Bank et al. (2021) however, Theramenes resulted as the sister group of the genus Tisamenus Stål, 1875 ,which Hennemann et al. (2016) had placed in the Tisamenus -group of Obrimini .

Distribution. – Talaud Islands and Philippines (Mindanao, Panay and Cebu).

Species included

1. Theramenes dromedarius Stål, 1877: 68 . Distribution: Philippines.

2. Theramenes exiguus Hennemann & Conle, 2003: 104 , Fig. 1-3.

Distribution: Panay.

3. Theramenes letiranti n. sp.

Distribution: Mindanao.

4. Eubulides mandirigma Zompro & Eusebio, 2001: 23 , Fig. 1-3.

Comments: As already pointed out by Hennemann et al. (2016:19) this species is very similar to T. dromedarius Stål, 1877 and merely differs by the smaller size, smaller anterior mesonotal swelling and less developed armature of the meso- and metapleurae. Thus, it is possible that this species may sometime prove to be a synonym of Stål’s species, for which no exact locality is known. Originally described from the ♂ only, the ♀ and egg were described and illustrated by Seidenschwarz (2018).

Distribution: Cebu.

5. Theramenes olivaceus ( Westwood, 1859: 65, pl. 2: 8).

Distribution: Talaud Islands.

Theramenes letiranti n. sp.

( Fig. 1-3)

ZooBank: https://zoobank.org/NomenclaturalActs/

120F1CD9-970D-4376-971D-00A60CB82A6D

Theramenes sp. , Bollens, Krijns & Bresseel, 2010: 23, fig. (penultimate instar ♀).

Bank et al., 2021: 13, fig. 6 (in molecular tree).

Holotype, ♂, Philippinen, Mindanao Id., Lanao del Sur Prov., Kapatagan Munip., local collector II.2012 [ IMQC, ex coll. FH].

Paratypes

- 2 ♂, Philippinen, Mindanao Id., Lanao del Sur Prov., Kapatagan Munip., local collector II.2012 [ FH, No’s 1290-1 & 2] .

- 1 ♀, 1 ♂, Philippinen, Mindanao Id., Lanao del Sur Prov., Kapatagan Munip., local collector IX.2011 [ FH, No’s 1290-3 & 4] .

- 1 ♂, Philippinen, Mindanao Id., Lanao del Sur Prov., Kapatagan Munip., local collector VII.2012 [ FH, No’s 1290-5] .

- 1 ♀ 1 ♂, 1 ♀ (juvenile), Philippinen, Mindanao Id., South Cotobato Prov. , Kidapawan, ca. 30 m, local collector IX.2012 [ FH, No’s 1290-6 to 8] .

- 1 ♂, Philippinen, Mindanao Id., South Cotabato Province, T’Boli, Daguma Mts., Mount Parker. ,local collector III.2013 [ FH, No’s 1290-9] .

- 1 ♀, Philippines, Mindanao , Mt Apo , Lake Agco Area, Apr, 2010 [ RBINS] .

- 1 ♀, Philippines, Mindanao, Bukidnon, Valencia , IV.2011, I. Lumawig, Local collector [ RBINS] .

- 1 ♂, Philippines, Mindanao, Surigao del Sur, Barobo , dec. 2013, I. Lumawig [ RBINS] .

- 1 ♂, Philippines, Mindanao, Davao del Sur, Cabagayan , II.2011 [ RBINS] .

- 1 ♂, Philippines, Mindanao , Mt. Apo, trail from basecamp, leg T . Buckley, 9. VII .2010 , gift S. Bradler, SB0286 [ RBINS].

Etymology. – This distinctive new species is named in honour of Stéphane Le Tirant (collection manager of the Montréal Insectarium IMQC, Canada) for his tremendous support and generosity in obtaining specimens as well as the friendship over several years, but also for his huge contribution to the knowledge of leaf-insects (Phasmatodea: Phylliidae ). His versatile efforts are an eminent gift to modern entomology and have also notably contributed to the present paper, why the author is obliged of being able to name such a remarkable stick insect after a great and exceptional personality in entomology.

Differentiation. – This striking new species is readily separated from all other congenerics by its small size, with ♀ being <60.0 mm and ♂ <40.0 mm in body length. Moreover, it is the so far only recorded representative of Theramenes from the island of Mindanao. Morphologically, it comes closest to the type-species T. olivaceus from the Talaud Islands, although a pre-median mesonotal swelling is only shared with T. mandirigma . In this latter species however, there is a prominent pair pre-median pair of conical mesonotal spines, whereas there is only an obtuse bi-gibbose swelling in letiranti n. sp., and mandirigma also has the abdominal segments very strikingly unequal in length and the metafemora much more prominently inflated than this new species. Males may also be separated from those of olivaceus by the presence of the aforementioned bi-gibbose pre-median swelling of the mesonotum ( Fig. 3 E-G) and different colouration, being basically ochraceous to testaceous with the head, prothorax and tibiae olive and the femora dark purple, whereas olivaceus is mostly olive-green

FAUNITAXYS - ISSN (Print): 2269 - 6016 - ISSN (Online): 2970 - 4960

A. Paratype, dorsal view [ FH 1290-2 ]. B . Paratype, dorsolateral view [ FH 1290-2 ]. C . Paratype, ventral view [ FH 1290-2 ]. D . Paratype, dorsolateral view [ FH 1290-1 ]. E . Paratype, dorsal view [ FH 1290-1 ]. F . Paratype, lateral view [ RBINS © Jérôme Constant]. with the meso- and metafemora red. Females can be distinguished from olivaceus by the somewhat stockier shape, somewhat more pronounced tubercles of the mesonotum and having only two small teeth in the apical half of the two lower carinae of the metatibiae ( Fig. 2 G-H) .

Description

Rather typical for the genus but the smallest known member. The colouration is described from dried and relaxed dried specimens.

♀ ( Fig. 1-2).

Small (body length 59.6-59.8 mm) and very heavy-bodied for the genus with comparatively pronounced meso- and metathoracic tubercles.

Colouration. – The three paratypic ♀ at hand differ notably in colouration. Two are basically dark olive with an ochraceous wash and the abdomen rather mid brown, which however is most certainly caused by the preservation ( Fig. 1 A-B, F). The other is buff to ochre with an olive wash on the head, prothorax and limbs and all over flecked with greyish brown ( Fig. 1 D-E). Ventral surface pale ochre and rather plain in colour ( Fig. 1C). All major thoracic tubercles dark orange to dark red, the granulations rather mid orange ( Fig. 2 A-C). Cephalic tubercles tipped with green. Femora with irregular faint washed darker markings. Eyes dark ochraceous. Antennae brown with a slight olive hue and becoming gradually darker towards the tip.

Head ( Fig. 2 A-B). – Sub-quadrate in dorsal aspect ( Fig. 2B) with the vertex weakly rounded. Diameter of eye contained less than 2x in length of gena. Median coronals obtusely conical and roughly equal in size to lateral coronals and anterior pair of occipital medials. Median supra-orbitals and supra-antennals only represented by small tubercles. Genae unarmed. Antennae consisting of 26 joints and reaching to abdominal segment II; joints gradually increasing length towards tip.

Thorax ( Fig. 2 A-C). – Pronotum relatively large, transverse with anterior margin notably concave. In anterior half with a prominent pair of obtuse, conical anterior pronotals; a small pair of medial pronotals present and consisting of 2-3 compound tubercles. Lateral margins with 2-3 sub-globose laterals. Mesothorax distinctly trapezoidal in dorsal aspect and sparsely set with fairly distinct, low granules. Anterior mesonotals prominent, conical; anterior mesal tubercles notably smaller. Two pairs of pre-median tubercles present, of which the posterior pair is more pronounced and situated close to the median line; the anterior pair more widely spaced. Posterior of mesonotum with a fairly distinct but low and sub-globose pair of swellings medially. Mesopleurae with about eight variably sized obtusely spiniform laterals; a compound supra-coxal present. Metanotum transverse and with a fairly small median pair of swellings that is surrounded by a few somewhat enlarged granules. Metapleurae with about seven blunt laterals; the supra-coxal indistinct. Meso- and metasternum with a fine but distinct medio-longitudinal line and a few paired low tubercles; these more pronounced on mesosternum.

Abdomen ( Fig. 2 D-F). – Mediansegment unarmed. All terga smooth except for a few small median granules on II; IV-VII with lateral margins somewhat deflexed and rounded; III-VII on average 5x wider than long. VII and VIII with a small and obtuse ppsteromedian swelling. Sterna smooth. Posterior margin of sternum VII weakly bi-labiate with a median indention (= praeopercular organ). Tergum IX strongly convex with the posterior margin somewhat elevated medially. Anal segment strongly declining and narrowing towards the posterior; the posterior margin weakly concave. Epiproct somewhat longer than anal segment, strongly up-curved, the apex obtusely rounded and with a few minute denticles. Subgenital plate strongly-up-curved, deeply keeled mediolongitudinally and tapering towards a narrow and acutely pointed tip, that projects somewhat beyond the epiproct.

Legs ( Fig. 2 G-H). – All relatively short and stout; no medioventral carina. Two ventral carinae of meso- and metafemora with five teeth that increase in size towards apex of femur (more distinct on metafemora); dorsal carinae only with five small teeth. Meso and metatibiae smooth dorsally, the two ventral carinae with three (mesotibiae) or 4-5 teeth, of which only the two apical ones are well developed. Profemora with dorsal carinae only with five very indistinct teeth indicated, anteroventral carina with only a distinct sub-apical tooth and posteroventral carina without noteworthy dentations; protibiae wholly unarmed. Tarsi short, stout and more than half the length of corresponding tibiae.

♂ ( Fig. 3).

Small for the genus (body length 31.2-33.8 mm) with distinct posteromedian swellings on meso- and metanotum and a small pair of pre-medial swellings.

Colouration. – Colourful insects; basic colour of body ochre with a slight olive hue on the terminal abdominal segments; head, prothorax, all coxae and all tibiae olive green; all femora dark purple with the base and apex green; ventral surface dark orangey except for an olive prosternum. Meso- and metapleurae dark red. Prothoracic and anteriors of mesonotum orange tipped; the posteromedian swellings of the meso-. And metanotum and the pair of pre-medial mesonotals swellings black. Antennae orangey pale brown with the two to five basal joints green.

Head ( Fig. 3 F-G). – Basically, as in ♀ but rather flattened and all tubercles lower and more obtuse. Antennae as in ♀ but relatively longer and reaching to posterior margin of abdominal segment V .

Thorax ( Fig. 3 F-G). – Pronotum as in ♀ but sub-quadrate in shape and all tubercles less pronounced, the laterals except for the posterolaterals wanting; only the pair of anterior pronotals similarly distinct as in ♀. Mesonotum less than twice the length of pronotum with the posterior half widened and notably inflated. Anterior mesonotals moderately distinct but very obtuse, the antero-laterals indistinct. In anterior half with a narrowly spaced pair of fairly distinct sub-globose pre-medial swellings close to mid-line. Posterior portion with a very prominent basically bi-globose but compound median swelling. A similar but slightly larger post-medial swelling on metanotum. Meso- and metapleurae only with about five (mesopleurae) or four (metapleurae) obtuse tubercles; supra-coxal of mesopleurae compound and fairly distinct, that of the metapleurae simple and very flat. Meso- and metasternum with a shallow medio-longitudinal carina and set with a few very low paired tubercles; a somewhat more pronounced posteromedian tubercle on metasternum,

Abdomen ( Fig. 3 H-K). – Notably narrower than thorax. Median segment with anterior margin convex medially. Segments II-VI noticeably decreasing in length, VII about as long as VI and almost 4x wider than long. II trapezoidal and slightly wider than long, III sub-quadrate, IV -VI increasingly transverse. All unarmed except for a very indistinct post-medial pair of granules close to the fine medio-longitudinal line. Sterna smooth. Terga VIII and IX with a slight posteromedian swelling, IX strongly convex. Anal segment notably longer than IX, declining and somewhat narrowing towards the roundly angular and weakly concave posterior margin; anterolateral angles protruded into an obtuse-tooth-like projection. Epiproct fairly large, transversely shield-shaped and projecting notably beyond anal segment. Vomer basically triangular in shape with a short terminal hook. Poculum distinctly bulgy, cup-shaped with the posterior margin entire, broadly rounded and almost reaching to tip of anal segment; the inclining posterior portion with a weak medio-longitudinal carina. Cerci very small and hidden under anal segment.

Legs. – Generally, as in ♀ but all teeth, but the ventral ones of the meso and metafemora much more distinct with the apical two (mesofemora) or three (metafemora) represented by strong spines. Lower carinae of mesotibiae only with weakly indicated tooth-like swelling; metatibiae with two moderately distinct teeth in apical half.

Remarks. – Eggs unknown and nothing is known about the habits and host-plants.

Distribution. – Mindanao, endemic. S-Mindanao: Province Davao del Sur (Kapatagan [IMQC; FH]; Cabagayan [RBINS]); Province South Cotobato (Kidapawan [FH]; Mount Apo, Lake Agco area [RBINS]; T’Boli, Daguma Mountains, Mount Parker [FH]). Central Mindanao: Province Bukidnon (Valencia [RBINS]).

FAUNITAXYS - ISSN (Print): 2269 - 6016 - ISSN (Online): 2970 - 4960

A. Paratype, dorsolateral view of head, pro-, meso and metathorax [ FH 1290-2 ]. B . Paratype, dorsal view of head, pro-, meso- and metanotum [ FH 1290-2 ]. C . Paratype, lateral view of head, pro-, meso- and metathorax [ RBINS © Jérôme Constant]. D . Paratype, terminalia lateral view [ FH 1290-1 ]. E . Paratype, terminalia dorsal view [ FH 1290-1 ]. F . Paratype, terminalia ventral view [ FH 1290-1 ]. G. Left hind leg in ventro-lateral view [ FH 1290-1 ]. H. Left hind leg in intero-lateral view [ FH 1290-1 ] .

Table 1. Measurements of Theramenes letiranti n. sp.

Keys to the species of Theramenes View in CoL ♂

1. Meso- and metapleurae granulose to obtusely tuberculose........................................................ 2

–– Meso- and metapleurae with prominent conical spines................................................ dromedarius View in CoL

2. Mesonotum with one prominent posteromedian swelling......................................................... 3

–– Mesonotum with two median swellings, one posteriorly and a smaller one (may be paired) pre-medially.......... 4

3. Green; meso- and metapleurae with distinct, blunt black tubercles; abdominal segments II-VI slightly gradually decreasing in length; Talaud Islands..................................................................... olivaceus View in CoL

–– Brown; meso- and metapleurae only with small tubercles; abdominal segments II-IV just slightly unequal in length, IV with anterior and posterior margins strongly arched, VI and VII less than one-third the length of II-IV; Philippines (Panay Island)................................................................................ exiguus View in CoL

4. Body length> 40.0 mm; mesonotum with antero-lateral very strong and with a prominent pair of conical pre-medial spines; abdominal segments II-VII distinctively unequal in length and IV with anterior and posterior margins strongly arched; Cebu ............................................................................... mandirigma

–– Smaller (body length <35.0 mm); mesonotum only with a single, obtusely bi-gibbose pre-medial swelling; Abdominal segments II-VI rather gradually decreasing in length and anterior and posterior margins of IV almost straight; Mindanao................................................................................. letiranti View in CoL n. sp.

♀

1. Meso- and metapleurae spinose................................................................................. 2 –– Meso- and metapleurae granulose to obtusely tuberculose....................................................... 3

2. Body length <75.0 mm; pair of median pronotals, anterior and pre-median mesonotals very prominent; antero-lateral of mesopleurae not larger than proceeding mesopleural spines; posteromedian protuberance of meso- and metanotum distinct; Cebu ........................................................................... mandirigma

–– Larger (body length> 80.0 mm); median pronotals, anterior and pre-median mesonotals moderate; antero-lateral of mesopleurae notably larger than proceeding mesopleural spines; posteromedian protuberance of Meso- and metanotum indistinct............................................................................... dromedarius

3. Large (body length> 75.0 mm)................................................................................. 4 –– Small (body length <65.0 mm); Mindanao......................................................... letiranti n. sp.

4. Green; meso- and metapleurae with prominent obtuse tubercles; Talaud Islands.......................... olivaceus –– Brown; tubercles of meso- and metapleurae less numerous, smaller and rather spiniform; Philippines (Panay

Island).................................................................................................. exiguus

FAUNITAXYS - ISSN (Print): 2269 - 6016 - ISSN (Online): 2970 - 4960

A. Holotype, dorsal view [ IMQC]. B . Holotype, dorsolateral view [ IMQC]. C . Paratype, dorsal view [ FH 1290-6 ]. D . Paratype, ventral view [ FH 1290-6 ]. E . Paratype, lateral view of body [ FH 1290-6 ]. F . Paratype, dorsal view of head, pro-, meso and metathorax [ FH 1290-6 ]. G . Paratype, ventral view of head, pro-, meso- and metanotum [ FH 1290-6 ]. H . Paratype, terminalia lateral view [ FH 1290-6 ]. J . Paratype, terminalia dorsal view [ FH 1290-6 ]. K . Paratype, terminalia ventral view [ FH 1290-6 ] .