Trachyaretaon bresseeli, Hennemann, 2023

Trachyaretaon bresseeli View in CoL n. sp.

( Fig. 55- 57, 72N & 74 G-H)

ZooBank: https://zoobank.org/ 63B72699-AC14-49BB-AE42-107A7786250B

Trachyaretaon echinatus, Bollens & Krijns, 2010: 18 View in CoL , figs. Harman, 2015: 26. [Note on culture stock].

HT, ♀: Philippines, Luzon , Aurora Prov., VII.2009, leg. Bellemans, Van Dingenen, Derijck [ RBINS] .

PT, 3 ♀, 2 ♂: Philippines, Luzon , Aurora Prov., VII.2009, leg. Bellemans, VanDingenen, Derijck [ RBINS] .

PT, 5 ♀, 11 ♂: Philippines, Luzon , Aurora Prov., VII.2009, leg. Bellemans, VanDingenen, Derijck;excultureBresseel,2010[ RBINS] .

PT, 22 ♀, 25 eggs: ex Zucht F. Hennemann 2012-2013, Cagayan Valley, Prov. Nueva Vizcaya, Imugan Falls , 900-950 m, 2015 [ FH, No’s 1467-1 to 22,E] .

PT, 11 ♀, 11 ♂: ex Zucht F. Hennemann 2012-2013, Philippinen, NELuzon, Cagayan Valley, Prov. Aurora, Cunayan / Ditumabo Falls nr. San Luis, leg. Bresseel 2009, PSG No. 317 [ FH, No’s 1467-23 to 45] .

Differentiation. – This new species is morphologically very close to T. mangyan n. sp. from Mindoro and T. nakatago n. sp., the latter of which also occurs in northern Luzon. With mangyan it shares the stocky overall shape and rather poorly developed body armature. Females are very similar and may only be separated by the very indistinct to wanting medio-longitudinal carina on the meso- and metasternum ( Fig. 56G), narrower posteromedian emargination of abdominal sternum VII ( Fig. 56C), somewhat deeper and broader posteromedian notch of the anal segment ( Fig. 56B) and the more incrassate femora, which have all the dentations notably larger and broader. Males can be distinguished by the less pronounced and shallower medio-longitudinal carina of the meso- and metasternum ( Fig. 56H), slightly more incrassate metafemora, broadened and basally more expanded anal segment ( Fig. 56E), medially notched and weakly bi-lobate posterior margin of the poculum ( Fig. 56F, narrowly rounded in mangyan ) as well as the broader and heart-shaped vomer, which has the terminal point comparatively shorter ( Fig. 72N). The eggs ( Fig. 74 G-H) represent the most reliable distinction from mangyan , and clearly distinguish bresseeli by having the posterolateral extension of the micropylar plate small and not expanded towards the anterior as in mangyan . From the morphologically very similar nakatago n. sp. ♀ of this new species merely differ by the notably smaller size and somewhat stockier shape, larger ventral teeth of the femora, less distinct mesosternals and much less pronounced to wanting medio-longitudinal carina of the meso- and metasternum ( Fig. 56G).Males maybeseparatedfromthose of nakatago bythemuchlessdistinctmediolongitudinalcarina of themeso- andmetasternum ( Fig.55K, 56H),larger ventral teeth of the meso- and metafemora but slenderer metafemora that have the dorsal subapical portion not inflated like in nakatago , as well as the bi-labiate and medially indented posterior margin of the poculum ( Fig. 56F, 72N). The eggs ( Fig. 74 G-H) are also very similar to those of nakatago and may only be distinguished by the more narrowed polar half of the capsule and slightly less downward directed posterolateral expansions of the micropylar plate.

From the type-species T. echinatus , which also occurs throughout Luzon, this new species can be separated by the stockier shape and less developed elements of thoracic armature but in particular, the notably smaller and not peg-like posterior mesonotals and metanotals of ♀, and lack of a posteromedian excrescence or dentiform protrusion on abdominal terga V-VII in ♂. Females can furthermore be distinguished by the less triangularly expanded posterolateral angles of abdominal terga IV-VII ( Fig. 55 A-C), the very indistinct to wanting medio-longitudinalcarina on themeso-andmetasternum( Fig. 56G),muchless pronounced armature of the abdominal terga, more deeply emarginated posterior margin of the anal segment ( Fig.56B) and not notably notched apex of the epiproct. Males can additionally be distinguished by lacking the characteristic black ventral surface of the coxae seen in echinatus ( Fig. 59G) as well as the much less distinct medio-longitudinal carina of the meso- and metasternum ( Fig. 56G), basally much broader anal segment ( Fig. 56E,just slightly narrowing towards posterior in echinatus ), the medially notched posterior margin of the poculum ( Fig. 56F) and broader, hear-shaped vomer which has the terminal point notably shorter and rather conical ( Fig. 72N, hook-like in echinatus ). The eggs ( Fig. 74 G-H) are very similar to those of echinatus and merely differ by the slightly larger dimensions, having the operculum inserted into the capsule at a right angle (opercular angle 5° in echinatus ) and the anterior extension of the micropylar plate less narrowed towards the apex.

Etymology. – This new species is named after Joachim Bresseel (Zermst, Belgium), who first collected specimens and established a culture in Europe, toacknowledge hisgenerosity in makingthe extensive Obrimini material in the collection of RBINS,much of which was collected by him, available for this study and for the good friendship over many years.

– A. ♀ paratype, dorsal view [ FH 1467-5 ]. – B . ♀ paratype, dorsal view [ FH 1467-13 ]. – C . ♀ paratype, dorsal view [ FH 1467-28 ]. – D . ♀ paratype, dorsolateral view [ FH 1467-5 ]. – E . ♀ paratype, ventral view [ FH 1467-13 ]. – F . ♂ paratype, dorsal view [ FH 1467-37 ]. – G . ♂ paratype, dorsal view [ FH 1467-39 ]. – H . ♂ paratype, dorsolateral view [ FH 1467-37 ]. – J . ♂ paratype, dorsolateral view [ FH 1467-39 ]. – K . ♂ paratype, ventral view [ FH 1467-37 ] .

Description

The colouration is described from colour photos of live wild and captive reared specimens.

♀ ( Fig. 55 A-E)

Form and colouration. – Moderately sized (body length 71.0-87.0 mm) and very stocky for the genus with moderately developed body armature and fairly low, but conical and multi-tuberculated posterior meso- and metanotals; body surface sparsely and unevenly granular to tuberculate and with a fine and rather obscure dorsal medio-longitudinal carina; the meso- and metasternum with the medio-longitudinal carina obscure to almost wanting. Colour very variable and ranging from various tones of dark to mid brown over buff and ochre toolive, although tonesof mid brownare clearlydominant; colour mostly heterogenous and with darker and lighter portions. Abdominal terga II-IV usually darker in colour than other segments and lateral surfaces with a characteristic inversely V-shaped black marking and almost always with a triangular black anterior lateral marking on tergum VIII; occasionally with a dark anteromedian marking on abdominal terga II-VIII. Pronotum usually lighter in colour than rest of thorax and with two faint dark and closely spaced parallel longitudinal streaks. Mesonotum with a more or lessclear pale cream or straw-coloured triangular anterior marking. Ventral bodysurface plain buff. Two more or less distinct roughlytriangular dark brown markings on frons;the eyes dark brown and flecked with yellow. Antennae dark brown with some dark yellowish annuli. Femora with anirregular shaped dark brown median band and the apical portion usually lighter in colour than the basal portion.

Head. – Scarcely longer than wide with vertex fairly inflated, conically roundedandslightlyprojectingoveranteriormarginof pronotum ( Fig.57E);the supra-antennals distinct and conical and with some smaller tuberculiform granules around the base; supra-orbitals very small and genae with 2-4 irregularly placed, small and rather nodular gulars. The two four coronals strong and conical, but the lateral coronals somewhat more pronounced than the median coronals;vertex with four strong occipital medials that areabout equal in size to eachother and to the median coronals; in front only with a closely spaced pair of small medials. Eyes moderately projecting with the anterior margin weakly angular, the diameter of eye contained about 2x in length of gena. Antennae with25jointsandreachingto posterior marginof abdominal segment III; the median antennomeres fairly elongated. Scapus compressed dorsoventrally and roundly rectangular, the pedicellus much shorter and slightly globose, III about 1.5x longer than pedicellus.

Thorax. – Pronotum about as longbut slightly narrower than head, longer than wide with lateral margins concave and with a deep roughly semi-circular pre-median excavation;the transverse median sulcus shallow, gently arched and expanding almost over entire width of segment; surface sparsely and unevenly nodulose. The posterior pronotals fairly strong but short, obtusely conical and the largest of the pronotal spines; antero-laterals small; the anterior portion only with an indistinct and small pair of posterior mesal pronotals and the posterior half merely with an even smaller pair of medial tubercles; the inter-posterior pronotals only represented by small tubercles ( Fig. 57E). Mesothorax gradually ascendant and widened towards the posterior, shape strongly trapezoidal with posterior margin about 2.4x wider than anterior margin; 2.1x longer than prothorax. Mesonotum less trapezoidal in outline and only with one or two small pairs of conicalpre-median tubercles (occasional alsoa smallpairof post-median tubercles present); compound posterior mesonotals rather low, conical and multi-tuberculated with the median tubercle somewhat enlarged, strong and conical ( Fig. 57E); lateral margins unevenly tuberculated. Mesopleurae increasingly widened towards posterior and with a moderately strong and conical mesopleural; the antero-lateral and two of the supra-coxals somewhat enlarged and obtusely spiniform; surface otherwise irregularly tuberculated. Metanotum subquadrate with anterior portion slightly narrowed, the posterior metanotals like those of the mesonotum;in front with a slightly enlarged pair of median tubercles and the lateral margins minutely tuberculose. Metapleurae progressively deflexed towards the posterior; the compound metapleural fairly large, strong and conical; the lateral margin unevenly tuberculated and with about four notably enlarged laterals. Meso- and metasternum only with a very obscure to almost wanting medio-longitudinal carina ( Fig. 56G); surface otherwise sparsely granulose and only with a few small and rather irregularly placed meso- and metasternals in the lateral sections.

Abdomen. – Median segment roundly trapezoidal in shape with anterior margin widely rounded and notably wider than long; the four posteriors only represented by small tubercles. Segments II-IV roughly uniform in width and slightly increasing in length, V somewhat widened and longer than preceding, VI-X narrowing with VI and VII slightly decreasing in length; V about 2.1x widerthan long.Lateral marginsof terga V-VII somewhatdeflexed andobtusely angular posteriorly; surface of II-V with a fine medio-longitudinal carina than becomes increasingly pronounced from II to VII and is posteriorly raised to form a rounded excrescence on VII; otherwise only with five (four on VI and VII) smallposterior tubercles. Sterna smooth except for ananterior and posterior pair of granules on II-VI. Praeopercular organ formed by a moderately broad, roughly semi-circular median excavation of posterior margin of sternum VII, which has the outer angles somewhat raised and swollen ( Fig. 56C). Terga VIII and IX each with low and obtuse posteromedian swelling formed by an excrescence of the medio-longitudinal carina ( Fig. 56A). Anal segment progressively narrowing; the anterior two-thirds strongly descendant and with a distinct and obtuse medio-longitudinal bulge; the posterior margin somewhat inflated and obtusely bi-dentate with roundly triangular indention medially ( Fig. 56B). Cerci small, triangular and strongly flattened laterally. Epiproct straight in lateral aspect, on average 1.5x longer than anal segment, obscurely tectate longitudinally, almost parallel-sided in basal half and just slightly narrowing posteriorly towards an obtusely angular apex, that is somewhat up-curved. Subgenital plate long, lanceolate and distinctly keeled in the apical half; the apex moderately pointed and slightly surpassing tip of epiproct ( Fig.56 A-C).

Legs. – Rather short and stocky for the genus with all femora notably incrassated and armed with prominent, triangular teeth. Basal flexure and constriction of profemora moderately developed; the two exterior ventral carinae with 2-3 big triangular teeth in apical one-third; the anterorsal carina with two and the posterodorsal carina with four teeth that strongly decrease in size towards the base of femur; the dorsal teeth lower but slightly broader than the ventral ones. All four carinae of meso- and metafemora with five teeth that become progressively smaller towards the base of femur with the two basal teeth rather minute; teeth on the ventral carinae acutely triangular in shape, those on the dorsal carinae low and somewhat broader; medioventral carina almost wanting and marked by some minute granules. Pro- and mesotibiae wholly unarmed,metatibiae onlywith a few small ventral denticulations in the apical half. Basitarsus about as long as proceeding three joints taken together.

♂ ( Fig. 55 F-K)

Form and colouration. – Size and general form average for the genus (body length 55.5-62.0 mm), body armature moderately developed with the posterior meso- and metanotals prominent, pointed and multi-tuberculose around the base; body surface sparsely granular to tuberculate; dorsal surface with a fine andveryobscure medio-longitudinal carina. Colour lessvariable than in ♀; mostly various tones of ochre, buff and mid brown and occasionally with some olive; posterolateral portion of mesonotum as well as lateral portions of metanotum and most of metapleurae darker than rest of body and usually reddish mid to dark brown;the dorsal surface of thorax with a more or less clear straw-coloured, pale ochraceous or sometimes slightly greenish medio-longitudinal streak. Pronotum mostly greenish laterally and with two closely spaced dark brown longitudinal streaks medially. Posterior meso- and metanotals aswellas meso- andmetapleuralsmostlymid todarkgreen.Ventral body surface rather uniformly buff to ochre. Poculum with a pair of distinct blackish markings posteriorly ( Fig. 56D, F). Limbs brown with some irregular ochre to dark green mottling.Eyes and antennae coloured as in ♀.

Head. – Shape and armature essentially as in ♀ but vertex somewhat more conical and all the spines slenderer and more spinose. Eyes relatively larger, projecting hemispherically and the diameter of eye contained a little less than 2x in length of gena.Antennae like in ♀ but reaching to abdominal segment IV.

Thorax. – Prothorax generallyasin ♀ butslightlynarrowingtowardsthe posterior, the lateral margins less concave and all elements of armature comparatively less pronounced; the posterior pronotals conical. Mesothorax fairly elongate for thegenusbeing 2.6x longer thanthe prothorax;anterior two-thirds slender and roughly uniform in diameter except for a slight widening at anterior margin, posterior portion strongly widened and inflated. Mesonotum densely granular and rather tubercular along lateral margins with a shallow and obtuse medio-longitudinal bulge but otherwise unarmed except for a small anterior mesonotal tubercles; posterior mesonotals prominent, strong, spinose and withafewsmall obtusetuberclesandgranulesaround thebase. Metanotum with medio-longitudinal bulge somewhat more pronounced than on mesonotum, the posterior metanotals like those of the mesonotum. Pleurae with armature essentially like in ♀ but much less pronounced, only the meso- and – A. Terminalia of paratype ♀ in lateral view [ FH 1467-5 ]. – B. Terminalia of paratype ♀ in dorsal view [ FH 1467-5 ]. – C. Terminalia of paratype ♀ in ventral view [ FH 1467-5 ]. – D. Terminalia of paratype ♂ in lateral view [ FH 1467-37 ]. – E. Terminalia of paratype ♂ in dorsal view [ FH 1467-37 ]. – F. Terminalia of paratype ♂ in ventral view [ FH 1467-37 ]. – G. Mesosternum of ♀ paratype [ FH 1467-5 ]. – H. Mesosternum of ♂ paratype [ FH 1467-37 ] .

metapleurallargerandmorespinoseinshape;the mesopleuraewitha somewhat enlarged and spiniform antero-lateral tubercle. Meso- and metasternum more densely granulose than in ♀; mesosternum with six indistinct, low and obtuse paired mesosternals( Fig. 56H); metasternum only with two smalltuberculiform metasternals laterally.

Abdomen. – Median segment almost semi-circular in outline and with an obtuse medio-longitudinal bulge; the five posteriors only represented by small tubercules and the median portion with two small pairs of nodes. Segment II trapezoidal, III-VI uniform in width, just slightly subuniform in length, III-V and on average 1.5x longer than wide; VII notably shorter than all preceding segments, clearlytrapezoidal and strongly widening towardsposterior.Terga II-VII with the medio-longitudinal carina becoming increasingly distinct towards VII, otherwise without any noteworthy armature except for a weakly indicated pair of latero-anteriors. Sternum II with a pair of low posterior tubercles, III-VI smooth. Terga VIII and IX transverse with lateral margins moderately deflexed and gently widening; IX with the lateral margin angular and somewhat protruded posteriorly and with a low, obtuse posteromedian swelling. Anal segmentbasically trapezoidal in dorsal aspect, beingnotably narrowedtowards the posterior; the lateral margins with a small and obtuse dentiform process anteriorly and weakly concave in the median section ( Fig. 56D); the posterior margin somewhat inflated andclearlybi-lobate witha distinct roundly triangular median emargination; dorsally with a shallow rounded pit near each outer posterior angle ( Fig. 56E). Epiproct fairly large, shield-shaped, almost semi-circular and notably projecting over posterior margin of anal segment. Vomer with base very broad and basically heart-shaped, the terminal point rather short, conical and distinctly arched towards the right ( Fig. 72N). Cerci strongly compressed laterally, small and roundly triangular. Poculum large, bulgy, obtusely cup-shaped and with an acute medio-longitudinal keel in the vertical posterior portion; posterior margin broad, moderately labiate and bi-lobate with a small triangular median indention ( Fig.56F).

Legs. – Basically, with armature like in ♀, but allteeth comparativelymuch smaller, more acute and rather spiniform;those on the dorsal carinae in particular much less pronounced; hind legs projecting considerably over apex of abdomen. The basal two teeth on the two exterior ventral carinae of the metafemora strong and spinose. Basitarsus slightly longer and slenderer than in ♀, the pro- and metabasitarsus notably longer than following three joints taken together.

Variability. – Considerable variability is seen in the often heterogenous colouration of ♀ in particular, which is largely summarized in the description above ( Fig. 57 A-C). Some variability can also be observed in the size and development of the cephalic and thoracic armature as well as the size and shape of the posteromedian excrescence of abdominal tergum VII. Males are generally much less variable in all aspects.

Egg ( Fig. 74 G-H)

Moderately sized for the genus; capsule elongate with the posterior half very scarcely narrowing, slightly oval in cross-section; about 1.8x longer than wide. Surface densely pitted; the anterior one-sixth and operculum covered with very short setae. Micropylar plate rather small and only about 0.65x the length capsule; basically Y-shaped with the median portion slightly narrowing anteriorly and the two posterolateral extensions small, oval and extending on lateral surfaces of capsule almost at an angle of 90°; surface of plate pitted like capsule and the outer margin weakly inflated. Posterior portion widely V-shaped with a minute bowl-shaped micropylar cup in centre. Median line distinct and formed by a narrow bulge that almost reaches to polar area. Operculum almost round with the outer margin flat and the inner portion weakly convex; inserted into capsule roughly at right angle. General colour plain greyish mid brown, the setose anterior portion of capsule and operculum sepia brown; outer margin of micropylar plate dark brown. Measurements [mm]: Length 4.5-4.6, width 2.6, height 2.4, length of micropylar plate 2.8.

Remarks. – Two culture stocksfromCagayanValley, Aurora Province have been introduced to Europe. The first stock was collected at the Cunayan and Ditumabo waterfalls by Joachim Bresseel (RBINS) in July 2009 and is the offspring of the holotype andparatypes.Thisculture was subsequently included on the Phasmid Study Culture List as culture No. 317 Trachyaretaon sp. ‘Aurora’ and is still being reared in captivity throughout Europe.Asecond parthenogenetic stock was introduced from the ImuganFalls but appearsto have been lost meanwhile.In captivitythis species readily accepts bramble ( Rubus spp. , Rosaceae ), hazel ( Corylus avellana , Betulaceae ), ivy ( Hedera helix , Araliaceae ) and pyracantha ( Pyracantha spp. , Rosaceae )as alternative foodplants.Itiseasyto culture in humid conditions and average temperatures of 22-25°C.

Distribution. – Northeast Luzon.