Mycovartes khoii, Bresseel & Constant, 2024

Bresseel, Joachim & Constant, Jérôme, 2024, Stick insects from Vietnam: The new genus Mycovartes gen. nov., with two new species and two new species of Neooxyartes Ho, 2018 (Phasmida: Lonchodidae: Necrosciinae), European Journal of Taxonomy 965, pp. 1-50 : 5-14

Mycovartes khoii gen. et sp. nov.

urn:lsid:zoobank.org:act:F36CCF2F-3F7A-44C1-8C3C-DBD056E9C24F

Figs 1–7

Diagnosis

Readily distinguishable from congenerics by the combination of the absence of tegmina and the orange colour of the anal part of the micropterous alae.

Etymology

The species epithet is a patronym dedicated to Mr Nguyễn Văn Khôi (Hanoi, Vietnam), our driver during many expeditions in the framework of the Global Taxonomy Initiative projects for over more than 10 years.

Type material

Holotype

VIETNAM • ♂; Dak Lak Province, Chu Yang Sin N.P. ; 12°27′24″ N, 108°22′15″ E; 9–15 Aug. 2019; 650–1000 m a.s.l.; GTI Project; J. Constant and J. Bresseel leg.; I.G.:34.048; RBINS.

Paratypes (19 ♂♂, 21 ♀♀)

VIETNAM – Dak Lak Province • 3 ♂♂, 1 ♀; same data as for holotype; RBINS • 2 ♂♂, 1 ♀; same data as for holotype; VNMN • 4 ♂♂, 5 ♀♀; same data as for holotype; ex breeding T. Bollens; 2021; RBINS • 2 ♂♂, 2 ♀♀; same data as for preceding; VNMN • 7 ♂♂, 9 ♀♀; same data as for preceding; FH 1282 1 to 16 . – Dak Nong Province • 1 ♂, 2 ♀♀; Ta Dung N.P. ; 11°52′22″ N, 107°58′40″ E; 5–8 Aug. 2019; GTI Project; J. Constant and J. Bresseel leg.; I.G.:34.048; RBINS • 1 ♀; same data as for preceding; VNMN .

Additional material

VIETNAM • eggs: same data as for holotype; ex breeding T. Bollens, 2021; RBINS .

Description

MEASUREMENTS. See Table 1 .

Male ( Figs 2 , 3A , 4 , 6A )

HEAD. Longer than wide, approximately rectangular in dorsal view and rugose. Dorsal portion fairly flat, with area between eyes slightly raised and granulose. Head capsule with several golden-brown tubercles. Back of head with six vague humps divided by shallow longitudinal furrows, central humps slightly more prominent. Eyes circular and strongly projecting.Antennae filiform, distinctly shorter than body with around 40 segments. Scapus dorso-ventrally flattened, lateral margins rounded, and broader than antennomeres. Pedicellus short, knob-like and circular in cross-section.

THORAX. Pronotum about as long as head, longer than wide and slightly constricted medially, anterior margin concave, posterior margin somewhat convex; with faint mediolongitudinal line and shallow transverse furrow medially. Dorsal surface with several scattered golden-brown tubercles. Mesonotum narrow and elongate with faint mediolongitudinal line, more than four times the length of pronotum. Anterior margin with four small but acute golden-brown spines; central pair not symmetrical, sometimes followed by few minute conical spines. Other portions with scattered golden-brown tubercles. Metanotum short, about two thirds of median segment with scattered golden-brown tubercles, anterior margin straight, posterior margin incurved.

WINGS. Tegmina absent. Alae very small, only slightly projecting over metanotum; costal area rugose, coloured as body; anal area orange without distinct venation.

LEGS. Profemora incurved basally and laterally flattened; all carinae present, with minute setae. Anterodorsal carina somewhat raised with pair of minute teeth distally. Mesofemora straight basally and laterally flattened; almost one third shorter than profemora. Medioventral carina indistinct, outer ventral carinae with pair of minute spines. Metafemora slightly longer than profemora, shaped as mesofemora. Protibiae slightly longer than profemora, somewhat laterally flattened. All carinae with minute stiff black setae. Mesotibiae about as long as mesofemora, metatibiae distinctly longer than corresponding femora. Meso- and metatibiae shaped as protibiae.

ABDOMEN. Median segment rugose, about one third longer than metanotum. Terga II–IX rugose, with posteromedian tubercle to flattened spine. Terga II–V more or less of same length, terga VI–X gradually shortening. Tergum II with posteromedian small spine, III–V with posteromedian armature gradually decreasing in size; IV and V often with indistinct tubercle posteromedially. Tergum VI slightly shorter than preceding segments with minute spine posteromedially, VII with flattened, small but acute spine posteromedially projecting over its posterior margin. Tergum VIII distinctly shorter than VII, somewhat trapezoidal with postermedian hump; tergum IX with indistinct median carinae ending in blunt hump posteromedially. Anal segment somewhat tectiform with posteromedian shallow notch, lateral margins sinuate; ventral portion armed with minute blackish spines/tubercles. Poculum shallow, reaching to/ slightly projecting over posterior margin of tergum IX and rounded posteriorly. Posteriorly with short mediolongitudinal carina. Vomer well developed, approximately triangular; basal portion broad, somewhat swollen, slightly narrowing toward the posterior and gently converging with the posterior half; posterior portion gradually narrowing with two asymmetrical upcurving teeth ( Fig. 4 ). Cerci short, reaching apex of anal segment, round in cross-section with apex rounded and incurving.

Female ( Figs 3B , 5 , 6B–E )

HEAD. Longer than wide, more or less rectangular in dorsal view and rugose. Dorsal portion fairly flat, head capsule with several goldish coloured tubercles. Back of head with six vague humps divided by shallow longitudinal furrows, central humps slightly more prominent. Eyes circular and projecting. Antennae filiform with between 40 and 50 segments, distinctly shorter than the body, not reaching halfway along the abdomen. Scapus somewhat dorsoventrally flattened, lateral margins rounded and broader than antennomeres. Pedicellus short, knob-like and circular in cross-section.

THORAX. Pronotum about as long as head and visibly longer than wide. Anterior margin concave, posterior margin almost straight, somewhat rounded; lateral margin distinctly concave. Dorsally with faint mediolongitudinal line and shallow transverse, slightly incurved, furrow medially. Dorsal surface with several scattered golden-brown tubercles; anterior margin with four tubercles. Mesonotum elongate with faint mediolongitudinal line, slightly shorter than four times the length of pronotum. Anterior margin with four small, narrow but acute spines; spine arrangements variable, sometimes followed by few minute conical spines. Other portions with scattered golden-brown tubercles. Mesopleura with longitudinal carina armed with minute lobes. Metanotum short, about two thirds the length of median segment with scattered golden-brown tubercles, anterior margin straight, posterior margin incurved.

WINGS. Tegmina absent. Alae very small, only slightly projecting over metanotum; costal area rugose, coloured as body; anal area orange without distinct venation; outer margin rounded, inner margin straight.

LEGS. Profemora incurved basally and laterally flattened; all carinae present, armed with minute setae. Anterodorsal carina somewhat raised and indistinctly sinuate. Mesofemora straight basally and laterally flattened; slightly shorter than profemora. Medioventral carina indistinct, posteroventral carinae with pair of minute spines posteriorly. Metafemora slightly longer than profemora, shaped as mesofemora. Protibiae slightly longer than profemora, somewhat laterally flattened and carinate. Mesotibiae slightly shorter than mesofemora. Metatibiae longer than corresponding femora. Meso- and metatibiae shaped as protibiae.

ABDOMEN. Median segment rugose, about one third longer than metanotum. Abdominal terga rugose; terga II–VI more or less of same length, VII–IX gradually shortening. Abdominal terga II–IX rugose with posteromedian armature; posteromedial process on these terga ranging from absent to a small granule, hump or minute flattened spine or to a broad circular process. Largest armature present on tergum VII; armature on all terga subject to strong variation. Tergum VIII distinctly shorter than VII, somewhat trapezoidal with posteromedian small hump; tergum IX with indistinct median carinae ending in blunt hump posteromedially. Anal segment arrowhead-shaped in dorsal view, basal portion broad and laterally somewhat rounded, thereafter narrowing towards the posterior with lateral margins strongly crenulate; apex narrow, pointed, but distinctly incised posteromedially. Subgenital plate short, reaching posterior margin of tergum IX, with distinct mediolongitudinal carina; posterior half with lateral margins rounded; posterior margin rounded with tiny triangular protuberance medially. Sternum VII without distinct praeopercular organ, medially with three irregular longitudinal carinae which are straighter and somewhat thicker posteriorly. Cerci short, not reaching apex of anal segment, tapering towards the posterior with a blunt, slightly incurved apex.

Nymph ( Fig. 6F )

Newly hatched nymphs slender and predominantly pale brown. Head bigger than pronotum, with darker postocular- and mediolongitudinal stripes. Mediolongitudinal darker stripe continuing on pro- and mesonotum though less distinct. Mesonotum, median segment and abdominal terga II–IX with small black posteromedian marking. Antennae brown with last two segments whitish. Legs coloured as body with apex of metafemora blackish.

Egg ( Fig. 7 )

Measurements (in mm): length: 2.5; width: 1.8; height: 2.0.

Capsule more or less oval with polar area somewhat flattened towards the dorsal surface, distinctly smaller than both other species in the genus. Colouration pale brown with unevenly dispersed and irregularly shaped black markings (sometimes almost absent); pale brown areas on capsule surface with minute, pale, mushroom-like armature. Micropylar plate positioned almost centrally on capsule but slightly displaced towards polar area; drop-shaped in outline, with anterior margin tapered and posterior margin rounded (somewhat variable); surface smooth with mediolongitudinal carina. Micropylar cup small. Micropylar plate posteriorly followed by a definite mediolongitudinal black line reaching polar area. Polar area blackish with pale center and unarmed. Operculum oval and convex; central portion with minute, pale, mushroom-like excrescences; portion with armature broader when compared with the two congeneric species. Other portions of operculum coloured darker than center and with somewhat thickened opercular rim.

Biology

The species was collected in mountainous tropical evergreen rainforest, at medium altitude (650– 1000 m a.s.l.). The specimens were observed on low vegetation and seemed to feed on a variety of plant species. The eggs are dropped to the ground.

In captivity, the species accepts Rubus sp. and other Rosaceae Juss. , Corylus avellana L. and Carpinus betulus L. ( Betulaceae Gray ) as food plants.

Distribution

This species is known from Chu Yang Sin N.P. and Ta Dung N.P. Both localities are situated on the Da Lat Plateau (also known as the Langbian plateau) in the Southern Annamites ( Fig. 1 ).

Figures

Fig. 1. Mycovartes gen. nov., distribution map.

Fig. 2. Mycovartes khoii gen. et sp. nov., holotype, ♂ (RBINS). A. Habitus, dorsal view. B. Habitus, ventral view. C. Head and thorax, dorsal view. D. Terminalia, dorsal view. E. Terminalia, ventral view. F. Terminalia, lateral view. G. Habitus, lateral view. H. Head and thorax, lateral view.

Fig. 3. Mycovartes khoii gen. et sp. nov. in situ. A. ♂ from Chu Yang Sin N.P. B. ♀ from Ta Dung N.P.

Fig. 4. Mycovartes khoii gen. et sp. nov., ♂ vomer. A. Ventral view. B. Posteroventral view. C. Lateral view.

Fig. 5. Mycovartes khoii gen. et sp. nov., paratype, ♀ (RBINS). A. Habitus, dorsal view. B. Habitus, ventral view. C. Head and thorax, dorsal view. D. Terminalia, dorsal view. E. Terminalia, ventral view. F. Terminalia, lateral view. G. Habitus, ventral view. H. Head and thorax, lateral view.

Fig. 6. Mycovartes khoii gen. et sp. nov. A. ♂, dorsal view. B. ♀, dorsal view. C. ♀ terminalia, dorsal view. D. ♀ terminalia, dorsolateral view. E. ♀ wings. F. Newly hatched nymph. Photographs ©T. Bollens.

Fig. 7. Mycovartes khoii gen. et sp. nov., eggs (RBINS). A. Lateral view. B. Dorsal view. C. Operculum. D. Ventral view. E. Dorsolateral view. F. Anterolateral view. G. Posterodorsal view. H. Polar area. I. Variation.