Nanophyllium daphne, Cumming & Tirant & Teemsma & Hennemann & Willemse & Büscher, 2020

Cumming, Royce T., Tirant, Stephane Le, Teemsma, Sierra N., Hennemann, Frank H., Willemse, Luc & Buescher, Thies H., 2020, Lost lovers linked at long last: elusive female Nanophyllium mystery solved after a century of being placed in a different genus (Phasmatodea, Phylliidae), ZooKeys 969, pp. 43-84 : 43

Nanophyllium daphne sp. nov. Figure 21

Type material.

Holotype ♀: Indonesia: Biak. 16/9.54; NNM-Leiden, ex collectie A. Veldhuyzen. In the collection RMNH, Leiden, Netherlands.

Discussion and differentiation.

This small species (body length of the holotype only 54.0 mm) has several interesting morphological features which differentiate it from other known Nanophyllium females. The tegmina venation places this species most closely aligned to N. chitoniscoides due to the venation pattern having the radial bend occurring before the splitting of the first radial and the radial sector, therefore the radial sector is straight (Fig. 9A ). Additionally, a radial and medial crossvein is present on the radial bend at or before the splitting of the first radial (Fig. 9A ).

This new species can be differentiated from all other Nanophyllium by several morphological features. First, it is the only species which has exterior profemoral lobes which are obtuse (Fig. 21A ), not right angles like in N. keyicum (Fig. 16D ) or recurved acute angles like in all other known Nanophyllium species (for example Fig. 16C ). Additionally, this is the only species known where the female has the abdomen tapering towards the posterior, giving the abdomen a spade-shaped appearance (Fig. 21C ), all other known species have females with abdominal segments VI and VII either parallel sided (like in N. frondosum and N. keyicum , Fig. 16C, D respectively) or as the broadest segments (like in N. chitoniscoides and N. suzukii , Fig. 16A, B , respectively).

These unique morphological features coupled with the geographic isolation from the mainland makes it unlikely that this female represents the unknown female sex of one of the many species which are only known from males from the mainland (Fig. 4 ). Instead, we here describe this species as Nanophyllium daphne sp. nov. as the first recorded Phylliidae species from Biak Island, Indonesia.

Description.

Female. Coloration. Presently, only the dried holotype specimen is known, which is fairly well-preserved with only minimal discoloration along the midline due to a lack of gutting. The majority of the body is of a pale light green coloration, with the areas of discoloration (such as the head, thorax, and shafts of the legs) being a pale brown/tan in coloration. Leaf insects are more vibrantly colored in life and it can be assumed that this specimen was a brighter green in life.

Morphology. Head. Head capsule slightly longer than wide, vertex with small granulation throughout the surface and unevenly spaced in no detectable pattern (some right next to each other some with more spacing). The posteromedial tubercle is small, only slightly noticeable and split into two lobes. Frontal convexity stout, not prominently protruding, with a lumpy surface which is marked by numerous pale setae. Antennae. Antennae consisting of nine segments. The terminal segment has a narrower base than segment VIII, instead with a width only about as wide as segments IV or V, and it is about as long as the previous two segments combined length. All segments have setae present; segments I through III have sparse but long pale setae; segments IV through VIII have sparse, stout, tan setae; and the terminal segment IX has dense, stout, dark setae. Compound eyes slender and tightly formed to the head, only reaching across one quarter of the head capsule length. Ocelli absent. Antennal fields approximately the same dimensions as the compound eyes, wider than the base of the first antennomere, and not protruding back farther than the frontal suture. Thorax. Pronotum with anterior margin that is slightly concave and lateral margins that are straight that slightly converge to a broad, slightly convex posterior margin that is about the same width as the anterior rim (Fig. 21B ). The pronotum surface has moderate granulation throughout that is evenly spaced, and the pronotum surface has a moderate pit in the center and furrows along the sagittal and lateral planes (Fig. 21B ). Pronotum lacks prominent rims, with only the anterior rim moderately formed and with a rough texture (but no features as prominent as actual granulation present). Pro-, meso-, and metasternum with granulation throughout, with all granules evenly spaced and of even size. Prescutum wider than long, with an anterior margin 1.3 times wider than the posterior margin (Fig. 21B ). Prescutum lateral rims and surface of the prescutum with granulation throughout, but no prominent spination. No prescutum crest present, the surface is only slightly raised so it is not perfectly flat, but it is not prominent. Prescutum anterior rim slightly raised in the center but not prominent, and lacks a sagittal spine, instead there is only weak granulation throughout the rim which is similar to the granulation found on the prescutum surface. Mesopleurae start near the anterior margin but not flush with it, instead they begin notably wider than the prescutum anterior margin. Mesopleurae are nearly straight and diverge evenly along their length (Fig. 21B ). Mesopleurae margins on their anterior margin are marked by a prominent tubercle immediately adjacent to two more which are medium sized and followed by three small tubercles that are nearly evenly spaced throughout the remainder of the length of the mesopleurae with slight granulation interspersed (Fig. 21B ). Face of the mesopleurae has a granular surface similar to the texture of the prescutum disk and marked with a distinct pit near the middle of the surface. Wings. Tegmina long, reaching past the anterior margin of abdominal segment VIII. The subcosta (Sc) is the first vein in the forewing and arcs smoothly unbranched towards the wing margin. The radius (R) gently bends towards the wing margin almost immediately and along this bend (first on the medial side) there is a notable radius to media crossvein (R-M), then following this first branching, the radius branches (on the distal side) into the first radius (R1) which runs unbranched to the wing margin, and the remainder of the radius as the radial sector (Rs) runs unbent to the wing margin, terminating slightly past the wings mid-length. The media (M) runs nearly parallel with the cubitus along the wing margin (there is a slightly wider than side by side gap near the anterior, but the veins are almost touching throughout a majority of their length). The media anterior (MA) diverges near the wing mid-length and arcs smoothly towards the wing margin where it terminates approximately three-quarters of the way through the length of the wing; this is followed by a splitting of the media posterior (MP) which runs parallel with the media anterior as it smoothly arcs towards the wing posterior margin. Following the media posterior split there is a small media to cubitus crossvein (M-Cu) which runs briefly parallel side by side with and then fuses to the cubitus. The cubitus (Cu) is bifurcate, branching into the cubitus anterior (CuA) and cubitus posterior (CuP) which diverge evenly, and both terminate at or near the wing posterior apex. The first anal vein (1A) is simple and fuses with the cubitus near the wing anterior margin. Alae rudimentary. Abdomen. Abdominal segments II through the anterior one third of IV uniformly diverging, posterior two thirds of IV through the anterior half of V parallel, the remainder of the abdominal segments are roundly converging to the broad rounded apex giving the abdomen an overall rounded appearance. Genitalia. Subgenital plate short and rounded, starting at the anterior margin of segment VIII and extending only about halfway onto segment IX, with straight, uniformly converging margins. Subgenital plate is only about a third the length of the gonapophyses, leaving a significant amount of the gonapophyses exposed. Gonapophyses are long and slender, not quite reaching the apex of the terminal abdominal segment (Fig. 21E ). Cerci broad and slightly cupped, with a surface throughout that is rough in texture, and margins with only a few short setae, none prominent. Legs. Profemoral exterior lobe broad with a rounded obtuse angle, and slightly wider than the interior lobe. Edge of the profemoral exterior lobe without notable teeth but with a margin that is granular throughout the length (Fig. 21A ). Profemoral interior lobe narrower than the exterior and shaped as a slightly obtuse angle marked with four small teeth (Fig. 21A ). The proximal most tooth is very small, not much more than a bump along the margin, this is followed by a narrow gap, the first prominent tooth, then a larger gap twice as wide as the first, another prominent tooth the same size as the previous, a gap the same size as the first small gap, and then one more prominent tooth at the distal end which is about the same size as the previous two teeth. The gaps between teeth are not deep and looping, instead they are straight and shallow between each tooth (Fig. 21A ). Mesofemoral exterior lobe arcs smoothly from end to end and lacks dentition. The interior and exterior mesofemoral lobes are of a similar width. Mesofemoral interior lobe arcs end to end with three serrate teeth only on the distal quarter of the lobe, which is slightly wider than the proximal portion of the lobe. Metafemoral interior lobe arcs end to end with the distal end wider than the proximal, and seven to eight irregularly shaped teeth on the distal third of the lobe only. Metafemoral exterior lobe is thin, smooth, and hugs the metafemoral shaft without teeth. Protibiae lacking an exterior lobe. Protibiae interior lobe spans the entire length of the protibiae and is not particularly wide, only about the same width as the protibial shaft itself. The lobe is smoothly triangular and is slightly wider towards the distal half. Mesotibiae and metatibiae lacking exterior and interior lobes.

Measurements of holotype

[mm]. Length of body (including cerci and head, excluding antennae) 54.0, length/width of head 5.7/5.1, antennae 2.9, pronotum 4.0, mesonotum 2.7, length of tegmina 36.0, greatest width of abdomen 28.0, profemora 10.0, mesofemora 8.3, metafemora 9.9, protibiae 5.7, mesotibiae 6.4, metatibiae 8.2.

Etymology.

Noun. Named for the nymph Daphne of Greek mythology who was pursued tirelessly by the god Apollo and was eventually after pleading with her father for a way to escape the relentlessness of Apollo, was turned into a laurel tree. Derived from Greek, Δάφνη.

Distribution.

Currently only known from Biak Island, Papua Province, Indonesia.

Figures

Figure 4. Distribution map showing localities for the known and herein described species.

Figure 9. Female Nanophyllium genitalia, ventral view A Nanophyllium species NHMUK 012497230 B Nanophyllium species, Papua New Guinea, Central Province, Coll RC 16 - 224 C Nanophyllium species, Indonesia, West Papua, Mapia, Coll SLT D Nanophyllium chitoniscoides, Coll FH.

Figure 16. Notable known Nanophyllium females scaled to relative size A Nanophyllium chitoniscoides comb. nov. Coll FH B Nanophyllium suzukii comb. nov. C Nanophyllium frondosum comb. nov. D Nanophyllium keyicum comb. nov. (RMNH).

Figure 21. Female holotype of Nanophyllium daphne sp. nov. A front left leg showing lobes and serration B antennae, head, and thorax dorsal details C full body dorsal D thorax, lateral view E genitalia, ventral.