Trachyaretaon maliit, Hennemann, 2023

Trachyaretaon maliit View in CoL n. sp.

( Fig. 61-63, 71C & 72K)

ZooBank: https://zoobank.org/ 6D1EF327-0407-46C1-8B63-5788F7D80161

HT, ♂: Coll. I.R. Sc.N.B., Philippines, Luzon, Quirino, Sierra Madre , X. 2014, local collector, gift B. Kneubühler 2015 [ RBINS] .

PT, 2 ♀, 1 ♂: Coll. I.R. Sc.N.B., Philippines, Luzon , Mt. Prov, BontocBarlig, 1500-2000m, 17°1'48"N 121°14'48"E, 12.iv.2014, IG: 32700, Mission Leopold III funds, Constant J., Bresseel J. & Co. [ RBINS] GoogleMaps .

PT, ♀: Philippines, Benguet, Mount Pack , leg. T. Heitzmann & A. Kang, IV.2013 [ RBINS] .

PT, ♂: Philippines, North Luzon , Mt.Province, Mt.Barlig, VI.2013 [ RBINS] .

PT, ♀ (penultimate instar): Philippines, Luzon, Mountain Province, Mt. Polis , 3.VIII.2013, leg. T. Heitzmann & J.P. Ortega, I.G.: 32.267 [ RBINS] .

PT, ♂: Philippinen, Northern Luzon Id. , Mountain Province, Nueva Vizcaya, Balite, leg. I.O. Lumawig VII.1996 [ FH, No. 1454-1] .

PT, ♂: Philippinen, S-Luzon Id., Bicol Region, Provinz Sorsogon, Mount Bulusan , local collector IX.2012 [ FH, No. 1454-2] .

Differentiation. – This very distinctive new species is the smallest known representative of the genus and therefore readily separated from all other congenerics by the small size but also by the mostly green colour and mossy general appearance ( Fig. 63 A-B) as well as the distinct dentiform posterolateral angle of the abdominal terga (♀ in particular, Fig. 61). The ♀ most closely resembles that of the type-species T.echinatus , which also occurs on Luzon, but in addition to the much smaller size clearly differs by the much stockier shape and relatively shorter body segments, much lower composite posterior mesonotals and metanotals ( Fig. 61D) but comparatively stronger pre-median and median mesonotals ( Fig. 60D) as well as the notably larger ventral dentations of the metatibiae. The ♂ can be separated from all other known species in the genus by the short mesothorax, which is less than 2x longer than the prothorax ( Fig. 62L) as well as the triangular dentiform posterolateral projection of abdominal terga V-VII, the posterolateral lobe of terga VIII and IX and long epiproct, which considerably projects over the posterior margin of the anal segment ( Fig. 62 E-G, K). The characteristic laterally compressed posteromedian projection of abdominal terga, which is most prominent onV-VIII, is only shared with T.echinatus , but in this new species it is often much more developed ( Fig. 62B).

Etymology. – The name maliit (Tagalog = small) refers to the very small size of this new species. Tagalog is the language of the Tagalog people, the largest ethnolinguistic group of indigenous people in the Philippines, who live throughout most of the regions of Luzon.

Description

The colouration is described from the dried specimens and photos of the insects when alive. Most of the dried specimens are discoloured to buff and ochre due to provisional preservation in ethanol.

♀ ( Fig. 61)

Form and colouration. – Small (body length 53.1-59.5 mm) and stocky for the genus with strongly developed body armature and fairly low, multi-tuberculated posterior meso- and metanotals; body surface sparsely and unevenly tuberculate and with a fine medio-longitudinal dorsal carina that is raised into a posterior excrescence on abdominal terga. General colour various tones green, olive and ochre (the dried specimens rather drab to brown); lateral portions of meso- and metanotum with some sepia brown and abdominal terga VI-VIII with dark brown to blackish mottling laterally; abdomen occasionally with a pale medio-longitudinal stripe and tergum V sometimes lighter in colour and rather creamy grey. Ventral body surface fairly plain buff to ochre. Frons with two roughly triangular dark brown markings. Eyes fuscous, antennae drab with some light cream-coloured annuli. Legs with some irregular dark brown mottling.

Head. – As typical for the genus with the vertex moderately inflated and roundly convex ( Fig. 61D), scarcely longer than wide and broadest at the eyes; these large, projecting subhemispherically and diameter of eyes contained about 1.4x in length of gena. Supra-antennals strong and with a smaller interior spine at the base; only a rather small anterior pair of medial occipitals present and the genae with two gulars, of which the anterior one is tuberculiform and the posterior one spiniform. Median coronals prominent, conical and moderately pointed but notably smaller than the strong lateral coronals. Supra-orbitals very strong and conical and similar in size to the posterior pair of supra-orbitals;the pair of occipital medials much smaller and vertex in front with four small tubercles that roughly forma quadrate. Antennae reaching to abdominal segment V and consisting of 26 joints; scapus rather compressed dorso-ventrally and roundly rectangular in outline; pedicellus much shorter and round in cross-section; III much longer than pedicellus, the proceeding increasingly elongated and the terminal joints somewhat shortening.

Thorax. – Pronotum about as long but narrower than head, longer than wide, lateral margins with a distinct, almost semi-circular excavation pre-medially, the transverse median sulcus moderately impressed and just gently arched.Anterior margin only with small tubercles; the anterior portion with a strong and conical but rather short pair of anterior pronotals, the posterior half with several rather irregularly dispersed small and obtuse subtuberculose medials; posterior pronotals distinct and the largest of the pronotal spines; postero-laterals small and conical ( Fig. 61D). Mesothorax gradually ascendant and strongly widened towards the posterior, shape strongly trapezoidal with posterior margin about 2.2x wider than anterior margin; 1.7x longer than prothorax. Mesonotum less trapezoidal in outline but still notably narrowing towards the anterior; surface with a large and conical pair of pre-medial tubercles and four more closely spaced and similarly but somewhat unequally sized median tubercles; the lateral margins with 6-7 short and moderately distinct spiniform tubercles; posterior mesonotals rather low, obtusely conical, multi-tuberculatedswellings withthe central tubercle somewhat enlarged ( Fig. 61D). Mesopleurae increasingly widened towards posterior and with a low and obtusely conical, multi-tuberculated mesopleural; surface minutely tuberculated and with four strong, conical tubercles, that slightly increase in size towards the posterior. Metanotum notably narrowed anteriorly with the posterior margindistinctly emarginated and{-shaped; roughly in centre witha pair of large, obtusely conical tubercles; the posterior metanotals similar to posterior mesonotals but slightly more raised ( Fig. 61D). Metapleural a fairly large, unevenly shaped and multi-tuberculated swelling;the margins unevenly tuberculated and with about four tubercles somewhat enlarged. Meso- and metasternum ( Fig. 61C) each with a shallow, transverse posteromedian swelling thatis coveredby some glossy granules;mesosternum with a lateral row of four rather prominent but low, conical tubercles and about six paired knob-like tubercles medially; metasternum only with a single somewhat pronounced lateral tubercles and some scattered, unequally sized tubercles and nodes medially ( Fig. 71C).

Abdomen. – Median segment basically semi-circular but with anterior margin {-shaped; surface only with a small tuberculiform anteriors and medials, the posterior margin with six small conical tubercles. Segments II-VII just slightly subequal in length and all distinctly transverse; II-VII somewhat widening, V widest and 3x wider than long, VI-VIII gradually narrowing; terga III-VII with posterolateral angle protruded into a bi- or tridentate angular lobe, whichismostprominentonVIV-VI ( Fig. 61 A-C).Terga all with a medio-longitudinal carina that posteriorly terminates in a crenulate laterally compressed excrescence, which gradually increases in size from II-VII ( Fig. 61G). Terga II-VIII otherwise only with a small pair of latero-anterior tubercles, a notably smaller pair of anteriors and slender first and second paired posterior spines at posterior margin, the interior (first) pair of

– A. Habitus dorsal view. – B. Habitus dorsolateral view. – C. Habitus ventral view. – D. Head and thorax in dorsolateral view. – E. Terminaliain dorsolateral view. – F. Terminaliain dorsal view. – G. Terminaliain ventrolateral view. – H. Terminaliain lateral view.

– A. Habitus of paratype in dorsal view [ FH 1454-1 ]. – B. Habitus of paratype in lateral view [ FH 1454-1 ]. – C. Habitus of paratype in dorsolateral view [ FH 1454-1 ]. – D. Habitus of paratype in ventral view [ FH 1454-1 ]. – E. Terminalia of paratype in dorsal view [ FH 1454-1 ]. – F. Terminalia of paratype in ventral view [ FH 1454-1 ]. – G. Habitus of paratype in dorsal view [ RBINS]. – H. Habitus of paratype in dorsolateral view [ RBINS]. – J. Habitus of paratype in ventral view [ RBINS]. – K. Terminalia of paratype in dorsolateral view [ RBINS]. – L. Head and thorax of paratype in dorsolateral view [ RBINS] .

which is somewhat more pronounced; these also increasing in size from II-VII. Sterna smooth except for an antero-lateral pair of obtuse tubercles ( Fig. 61C). Sternum VII ascendant medially with posterior margin raised, widely emarginated and with the inter portion glossy ( Fig. 61 G-H). Terga VIII and IX with posterolateral angles just slightly deflexed and obtusely triangular ( Fig. 61F); IX with a distinct pair of latero-anterior tubercles and two small tubercles at posterior margin ( Fig. 61E). Anal segment progressively narrowing, strongly descendant and obtusely tectate medio-longitudinally; the posterior margin roundly angular and with a very shallow median indention ( Fig. 61F). Cerci small, conical and compressed laterally. Epiproct just very scarcely up-curved, about 1.7x longer than anal segment, weakly tectate longitudinally and slightly gradually narrowing towards a weakly notched apex ( Fig. 61F). Subgenital plate long, lanceolate and distinctly keeled in the apical half; the apex fairly pointed, slightly surpassing tip of epiproct and with tip slightly downward directed ( Fig. 61 E-H).

Legs. – Of moderate length with all carinae armed except for the dorsal carinae of the meso- and metatibia which are smooth. Ventral carinae of tibiae only with small dentations, although those of the metatibiae are more numerous, notably more pronounced and acutely pointed. Exterior ventral carinae of meso- and metafemora with 6-7 distinct teeth and a few much smaller intercalated teeth, which become increasingly more spiniform towards the apex of femur (metafemora in particular); the dorsal carinae with five broad teeth that strongly decrease in size towards the base of femur with the two apical ones very prominent and broad. Medioventral carina of meso- and metafemora only marked by some small granules. Tarsi rather elongate and more than half the length corresponding tibia; basitarsi elongate almost as long as proceeding three tarsomeres taken together.

♂ ( Fig. 62)

Form and colouration. – Size very small for the genus (body length 35.7-40.7 mm), general form rather stocky with a very short mesothorax that is only 1.8x longer than the prothorax and with a distinct posteromedian lobe on abdominal terga II-VII (V-VII in particular). Colouration rather complex and moss-like; basically, dark green to olive with lateral portions of meso- and metanotum and pleurae and abdominal terga rather brown; mesonotum, metanotum and occasionally also abdominal terga I-VII with a distinct and broad green medio-longitudinal streak. Meso- and metasternum mostly dark yellowish to ochre with the lateral regions greyish to black. Most of the thoracic tubercles and spines ochre to dull orange. Frons with a pair of triangular fuscous markings. Legs olive with faint, irregular brown and ochraceous mottling; the mottling rather orangey on ventral surfaces of metafemora and tibiae. Eyes dark orange. Antennae with two basal joints olive, all other joints reddish mid brown.

Head. – Shape and armature essentially as in ♀ but eyes larger and projecting almost hemispherically ( Fig. 62L). Antennae basically in ♀ but reaching to abdominal segment VI.

Thorax. – Pronotum shorter and narrower than head and slightly longer than wide.Armature principally as in ♀, butanterior margin unarmed, the posterior half with four small subtuberculose medial pronotals that are roughly arranged in a quadrate, and the posterior pronotals distinct but slightly smaller than the anterior pronotals ( Fig. 62L). Mesothorax short andbroad, only 1.8x longer than prothorax withthe posteriorportion stronglyinflated andwidened. Mesonotum only with a moderate subspinose pair of anterior mesonotals, three clustered median mesonotals and three small tubercles along lateral margins;posterior mesonotals prominent, tuberculoseandwithaprominentspineincentrewhichhas an irregular and obtuse keel anteriorlyandposteriorly ( Fig. 62L). Posterior metanotals like mesonotals but somewhat larger; a low and conical pair of median metanotals present; metanotum strongly inflated posteriorly and narrowed anteriorly ( Fig. 62L). Meso- and metaplaeurae increasinglydeflexed and inflated towards the posterior; meso- and metapleural moderately developed, obtuse and withsmaller tubercleabove.Mesopleuraewiththreesomewhat enlargedtubercles of which the antero-lateral is the most distinct one and slightly spiniform. Metapleuraewith twoprominent,irregularly carinatedsupra-coxalsandonlysome smalllateral tubercles. Mesosternum sparsely granulate with six fairlyprominent but low and conical mesosternals; metasternum with four much smaller metasternal ( Fig.62D,J).

Abdomen. – Median segment trapezoidal and with a small tuberculiform pair of first paired posteriors at posterior margin. Segment II distinctly trapezoidal, III-VII roughlyuniform in width,subquadrate and weaklysubequal in length. Terga III-IX each with the posterolateral angle protruded into an obtusely triangular, dentiform projection and with a node-like pair of anterior tubercles. II-VII with fairly small and obtuse first and second paired posteriors and a much more prominent posterior mesal; the latter laterally compressed, gradually increasing in size from II towards VII and most prominent and tridentate onVI; onVII lower but muchbroader thanon precedingterga (variable in size and shape, Fig. 62K)). Sterna II-VII with a fine but fairly acute medio-longitudinal carina and a pair of anterior tubercles, which is most pronounced in II. Terga VIII and IX each with a bi-tuberculose posteromedian protrusion; the first and second paired posteriors obtuse ( Fig. 62 E-F). Anal segment with a distinct, bluntly triangular, dentiform latero-basal projection and strongly narrowed in the posterior half; the posterior margin somewhat inflated and with a distinct almost semi-circular median excavation; dorsally with a shallow impression near each posterolateral angle ( Fig. 62E). Epiproct large, elongate, bi-fid at the apex and notably projecting beyond anal segment ( Fig. 62 E-F). Vomer dark orange, broadly triangular and gradually tapering towards a moderately long but rather obtuse terminal hook, that is dextral-directed by about 30°; basal portion somewhat impressed medially ( Fig. 72K). Cerci strongly compressed laterally, small. Poculum large, rounded, bulgy with the posterior margin broadly triangular and strongly labiate to form a fairly broad flange;vertical posterior portion with a fine median carina ( Fig.62F).

Legs. – Basically, as in ♀ but tarsi relatively more elongate and slenderer, the basitarsi about as long as proceeding three tarsomeres taken together.

Variability. – Slight variability is seen in the size,colouration and degree of the cephalic, thoracic andabdominalarmature as wellasthe dentations of the limbs.Colour variation is summarized in the descriptions above.It is noteworthy that the ♂ from Mount Bulusan is smaller than all other known specimens (body length 35.7 mm) and has the posteromedian excrescence of abdominal terga IV-VII notably more developed.

Remarks. – Eggs unknown.

Distribution. – Luzon.