Pulchriphyllium heracles sp. nov.

Cumming, Royce T., Le Tirant, Ste ́ phane, Linde, Jackson B., Solan, Megan E., Foley, Evelyn Marie, Eulin, Norman Enrico C., Lavado, Ramon, Whiting, Michael F., Bradler, Sven & Bank, Sarah, 2023, On seven undescribed leaf insect species revealed within the recent " Tree of Leaves " (Phasmatodea, Phylliidae), ZooKeys 1173, pp. 145-229 : 145

Pulchriphyllium heracles sp. nov.

Fig. 24

Material examined.

Holotype ♂: " Vietnam: Da Nang Province, Ba Na Mt. 1,450 m. elv. May 2015; Coll RC 16-007" (Fig. 24 ). Deposited in the Montreal Insectarium, Quebec, Canada (IMQC) . Paratypes: (37♂♂) See Suppl. material 1 for details about paratype specimens, their collection data, and depositories.

Differentiation.

Female, freshly hatched nymph, and egg unknown. Males are morphologically most similar to Pulchriphyllium maethoraniae (Delfossee, 2015) and Pulchriphyllium sinense (Liu, 1990). These three species are difficult to morphologically differentiate, especially because Pulchriphyllium maethoraniae and Pulchriphyllium sinense males are only known from a few specimens, therefore the intraspecific variation is not well understood. On average it appears the mainland species ( Pulchriphyllium maethoraniae and Pulchriphyllium heracles sp. nov.) are slightly larger than Pulchriphyllium sinense from Hainan Island, but that could simply be due to our limited knowledge of Pulchriphyllium sinense variation. One morphological feature which does appear to be consistent for differentiating Pulchriphyllium heracles sp. nov. from the other two is the interior lobe of the mesofemora. In Pulchriphyllium heracles sp. nov. the lobe is slightly thinner, with a maximum width of ca 1 ¼ the width of the mesofemoral shaft, whereas in the other two species this lobe is broader, ca 1½× as wide or wider.

Description.

Male. Coloration. Coloration description based on the dried type specimens, but despite slight discoloration from the preservation process, the natural patterns appear rather consistent. The coloration throughout is pale green with brown highlights/markings (Fig. 24 ). The antennae, head, thorax, and tegmina are typically yellow/tan but in life were probably green or tan. The lobes of the legs and the abdomen are green. Abdominal segment V with a set of eye spots, one on each side of the midline. The meso- and metafemora, tibiae, and the exterior lobe of the protibiae are uniformly brown. The protibia interior lobe and the profemoral interior lobe are muddled brown with patches of darker and lighter areas, and the profemoral exterior lobe is uniformly green.

Morphology. Head. Head capsule ca ¼ longer than wide, with a vertex that is smooth, lacking distinct granulation; the posteromedial tubercle is not prominent, only slightly raised above the head capsule (Fig. 24B ). Frontal convexities stout, not strongly projecting, ending in a blunt, rounded apex. Compound eyes are large and bulbous, occupying slightly < ½ of the head capsule lateral margins (Fig. 24B ). Between and slightly posterior to the compound eyes are three protruding, well-formed ocelli (Fig. 24B ). Antennal fields are slightly wider than the scapus width. Antennae. Antennae (including the scapus and pedicellus) consist of 24 segments. The scapus and pedicellus are smooth, lacking setae, the following 18 segments are covered evenly in thin, dark setae which in most cases are approximately as long as the antennae segment is wide. The terminal four antennal segments have short, dense setae, notably different from the long sparse setae on the other segments. Each antennomere on the distal end projects ventrally slightly, so the overall antenna has a serrate appearance. Thorax. Pronotum trapezoidal in shape, with the anterior width similar to the lateral lengths, and the posterior width ca ½ the anterior width. Therefore, the lateral margins distinctly converge to the narrow posterior (Fig. 24B ). Pronotum anterior margin slightly concave; lateral margins relatively straight to slightly converging. Anterior and lateral margins of the pronotum with distinctly defined rims (Fig. 24B ). Face of the pronotum is marked by a relatively smooth surface without heavy granulation or wrinkling. The only notable feature on the face of the pronotum is a slight sagittal furrow, a notable central pit, a moderately formed perpendicular furrow just anterior to the central pit, and two distinct pits along the anterior margin behind the anterior rim (Fig. 24B ). Prosternum and mesosternum relatively smooth, lacking granulation. Metasternum slightly wrinkled on the anterior and lateral margins, and heavily wrinkled on the posterior. Prescutum anterior wider than the prescutum is long, with lateral margins slightly converging to the posterior which is ca ⅙ narrower than the anterior rim width (Fig. 24B ). Prescutum lateral rims with slight granulation throughout their length (Fig. 24B ). The surface of the prescutum is mostly smooth with only moderate, sparse granulation. The prescutum surface is raised along the sagittal crest, which is slightly textured (Fig. 24B ). Prescutum anterior rim moderately formed but lacking a prominent sagittal spine (Fig. 24B ). Mesopleura narrow, diverging slightly on the anterior ⅗, and then widening slightly on the posterior ⅖ (Fig. 24B ). Mesopleuron lateral margin with five or six tubercles situated on the anterior ⅗ (with the tubercles increasing in size from the anterior to the posterior) and the posterior ⅖ of the mesopleuron is smooth, lacking tubercles (Fig. 24B ). Face of the mesopleuron slightly wrinkled and marked with one distinct pit near the middle. Wings. Tegmina short, extending partially onto abdominal segment II. Tegmen wing venation: the subcosta (Sc) is the first vein, runs relatively straight for ca ½ of the wing length and terminates on the margin. The radius (R) spans the entire length of the tegmen, running as the radial sector (Rs) straight through the center of the tegmen to the apex after the first radius (R1) branches near the center of the wing and runs to the posterior ⅓ margin where it terminates. The media (M) spans the entire length of the tegmen, running parallel with the radius (R) and radial sector (Rs) and terminates at the wing apex as the media anterior (MA) after the branching of a weakly formed media posterior (MP) near the middle of the tegmen which terminates slightly posterior to the tegmen midline. The cubitus (Cu) runs through the tegmen surface angled away from the media (M) for ca ⅓ of the length to the tegmen margin and then runs along the margin where it fades before meeting the apex. The first anal (1A) vein runs subparallel to the cubitus until they meet ca ¼ of the way through the tegmen length. Alae well-developed in an oval fan configuration, reaching onto abdominal segment VIII or IX. Ala wing venation: the costa (C) is present along the entire foremargin giving stability to the wing. The subcosta (Sc) is fused with the radius for the anterior ⅗ of the ala length, then splits and runs parallel with the wing margin until it fades before reaching the apex. The radius (R) branches ca ⅔ of the way through the ala length into the first radius (R1) and radial sector (Rs) which run gradually diverging through the first ½ of their lengths, then run parallel until fusing with the cubitus at different locations on the posterior ⅕ of the wing. The media (M) branches early, near the anterior ⅛ into the media anterior (MA) and the media posterior (MP) which run diverging for ⅓ of their lengths, then parallel for ⅓, and then converge for the final ⅓. The media anterior fuses with the cubitus (Cu) near the posterior ¼ of the ala length. The media posterior fades before fully fusing with the cubitus. The cubitus runs unbranched and terminates at the wing apex after the media anterior, first radius, and radial sector fuse with it at different locations. Of the anterior anal veins, the first anterior anal (1AA) fuses with the cubitus early on and then the first anterior anal branches from the cubitus ¾ of the way through the wing length where it uniformly diverges from the cubitus until it terminates at the wing margin. The anterior anal veins 2-7 (2AA-7AA) have a common origin and run unbranched in a folding fan pattern of relatively uniform spacing to the wing margin. The posterior anal veins (1PA-6PA) share a common origin separate from the anterior anal veins and run unbranched to the wing margin with slightly thinner spacing than the anterior anal veins. Abdomen. The abdomen’s general shape is boxy and broad with a maximum width of approximately ⅗ the abdomen length. Abdominal segment II diverges slightly, III diverges more prominently, IV is slightly angled with the anterior ½ diverging strongly and the posterior ½ running parallel, V through VII have margins which are nearly parallel, VIII converges slightly then arcs into a lobe on each side of the abdomen as it curls towards the genitalia, IX converges strongly inward towards the genitalia, and X projects away from IX into a pointed apex. Genitalia. Poculum rectangular in shape, broad with a width only slightly less than the width of abdominal segment X. The poculum ends in a margin which is relatively straight that passes just beyond the anterior margin of segment X (Fig. 24C ). Cerci ovular, not particularly long, with ca 1⁄2 of their length extending from under abdominal segment X (Fig. 24C ). The cerci are relatively flat, not strongly cupped, and have distinctly granular surfaces and setae throughout the surfaces. The cerci margins are marked with distinct, stiff setae. The vomer is triangular and stout with all margins approximately equal in length, with lateral margins relatively straight and converging evenly to the apex, which is armed with a singular stout hook curving into the paraproct. Legs. Profemoral exterior lobe broad and right angled, ca 1½× widener than the interior lobe. Profemoral exterior lobe proximal margin distinctly serrate, with four prominent teeth, with the proximal two the closest together and the other two variable on their location, either spaced evenly or both situated closer to the distal end of that margin. Profemoral exterior lobe distal margin typically smooth, lacking prominent serration, at most with slight granulation throughout or weakly formed teeth on the proximal end. Profemoral interior lobe begins approximately ⅓ of the way through the profemoral length, and arcs in a slight undulation with a maximum width of ca 3-4 × the profemoral shaft width. Profemoral interior lobe is marked by three teeth on the distal end of the lobe, the proximal most is small, followed by two broadly triangular teeth. Mesofemoral exterior lobe is roundly triangular, relatively evenly weighted from end to end, and broad, with the proximal margin straight and smooth, and the distal margin slightly arcing and marked by three to five distinct serrate teeth. The greatest width of the mesofemoral exterior lobe is ca 2 × the width of the mesofemoral shaft. The mesofemoral interior lobe is thinner than the exterior lobe and is unevenly weighted from end to end with the widest portion near the distal ⅓. The proximal ⅓ of the mesofemoral interior lobe is narrow with a rounded arc on the distal ⅔. There is unevenly spaced and variable sized serration throughout the full margin of the mesofemoral interior lobe (typically seven or eight serrate teeth). Metafemoral exterior lobe arcs thinly along the metafemoral shaft, with a maximum width slightly thinner than the metafemoral shaft width. Metafemoral exterior lobe lacks dentition throughout most of its length, with only the distal ⅓ marked by three or four small serrate teeth. Metafemoral interior lobe is narrow and straight for the proximal ½ and then on the distal ½ there is a small, rounded lobe that is approximately as wide as the shaft width. There is serration of variable size and spacing throughout the length (six to eight teeth), but the distal ½ is marked by more prominent serration. Protibial exterior lobe is a thin scalene triangle weighted towards the distal end which is ca 3 × as wide as the protibial shaft width. The protibial exterior lobe distal margin is marked with several small nodes and the remainder of the lobe is smooth. Protibial interior lobe is also a scalene triangle, but it is slightly wider than the exterior lobe, with the widest portion the distal ⅖, and the full length is smooth, lacking serration. Mesotibial exterior lobe is roughly a narrow right triangle which is weighted towards the distal ⅓ and has a greatest width ca 3 × the width of the mesotibial shaft. The broadest point of the mesotibial exterior lobe has slight granulation/small serration. Metatibial exterior lobe is roughly a broad right triangle which is weighted towards the distal ¼ and has a greatest width ca 3 × the width of the metatibial shaft. Mesotibiae and metatibiae lack interior lobes.

Measurements of holotype male Coll RC 16-007 [mm]. Length of body (including cerci and head, excluding antennae) 66.0, length/width of head 4.1/3.7, antennae 27.3, pronotum 2.9, mesonotum 3.6, length/width of tegmina 13.8/5.1, length of alae 52.3, greatest width of abdomen 25.0, profemora 14.0, mesofemora 9.7, metafemora 10.2, protibiae 8.1, mesotibiae 7.0, metatibiae 8.6.

Measurements of paratype males, given as a range for smallest to largest [mm]. Length of body (including cerci and head, excluding antennae) 59.4-71.4, length/width of head 4.0-4.5/3.3-4.0, antennae 25.4-27.6, pronotum 3.0-3.7, mesonotum 3.3-5.1, length/width of tegmina 11.9-15.7/4.8-6.0, length of alae 45.0-57.2, greatest width of abdomen 24.2-26.7, profemora 11.4-14.6, mesofemora 9.0-9.3, metafemora 9.0-9.5, protibiae 6.9-8.0, mesotibiae 6.7-7.8, metatibiae 6.6-8.6.

Etymology.

Proper noun, Greek in origin. Following a mythological trend started by Gray (1843) who named species based upon characters from the tenth labor of Heracles. Interestingly, despite several of Gray’s names following this myth, he never named a species following the main character, Heracles himself. We herein would like to close Gray’s phylliid focused chapter on the tenth labor of Heracles by bestowing the name upon a large and impressive species, worthy of such a mighty character.

Distribution.

Records for this species are primarily from southern and central Vietnam (from the provinces of Kon Tum, Da Nang, Gia Lai, Lam Dong, Quang Nam, and Thua Thien Hue) and additionally one record from the northern Vietnam province of Nghe An is known (Fig. 15B ).

Remarks.

Specimens of this Vietnamese population were originally thought to represent range expansions for Pulchriphyllium maethoraniae . Therefore, this population was tentatively identified within Bank et al. (2021) as Pulchriphyllium cf. maethoraniae due to a lack of true Pulchriphyllium maethoraniae samples from Thailand at the time. Yet, additional sampling from throughout mainland Asia (including in Thailand near the Pulchriphyllium maethoraniae type locality; Fig. 15B ) has revealed that this complex of similar-looking specimens are instead three well-defined species: Pulchriphyllium maethoraniae , Pulchriphyllium sinense , and the Vietnamese species herein described as Pulchriphyllium heracles sp. nov. (Fig. 24 ).

Interestingly, despite near identical morphology with Pulchriphyllium maethoraniae and Pulchriphyllium sinense , Pulchriphyllium heracles sp. nov. has been recovered in the molecular phylogeny as entirely unrelated to Pulchriphyllium maethoraniae and Pulchriphyllium sinense (which were recovered as sister to each other; Fig. 2 ). Hopefully future collection efforts in Vietnam will reveal the female, egg, and freshly hatched nymph morphology to allow better morphological comparison of Pulchriphyllium heracles sp. nov. with congeners.

Figures

Figure 2. Phylogenetic tree of the Phylliidae based on six nuclear and mitochondrial loci with a focus on Phyllium and Pulchriphyllium (please refer to Suppl. material 4 for the complete tree). Ultrafast bootstrap support values are depicted at each node. Specimens in green font are in addition to the already existing tree inferred by Bank et al. (2021). Highlighted in green boxes are the seven newly described species.

Figure 15. Distribution map for the herein discussed Pulchriphyllium species with known records plotted. For data on the distribution points used for this map, see Suppl. material 1 A distribution of the " Pulchriphyllium bioculatum - like species " B distribution of the Pulchriphyllium species from mainland Asia with a boxy abdominal shape (inset outline in A). Abbreviations: KH, Cambodia; LA, Laos; TH, Thailand; VN, Vietnam.

Figure 24. Pulchriphyllium heracles sp. nov. holotype male (Coll RC 16 - 007; IMQC) A habitus, dorsal B details of the head through thorax, dorsal C genitalia, ventral. Photographs by Steve Thurston (AMNH) using Microptics-USA / Visionary Digital photomicrographic system developed by Roy Larimer; using a Nikon D 300 DSLR camera, Infiniti optics, and a Micro Nikkor 60 mm lens. Multiple layers stacked using Helicon Focus.