Pulchriphyllium scythe (Gray, 1843) stat. rev., comb. 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 scythe (Gray, 1843) stat. rev., comb. nov.

Figs 16 , 17 , 18 , 21C

Material examined.

(♀): “Silhet” (OUMNH; Fig. 16 ), herein designated as the lectotype. See Suppl. material 1 for additional non-type specimens reviewed.

Differentiation.

Presently, Pulchriphyllium scythe stat. rev., comb. nov. is one of the species we lack molecular data for, but thankfully there are consistent morphological differences which allow differentiation from congenerics. At the moment, the morphology of the freshly hatched nymph and the egg are not known, which would likely yield additional features for differentiation. The female Pulchriphyllium scythe stat. rev., comb. nov. are the easiest to consistently differentiate, and when coupled with their geographic isolation, are the reason why we are reinstating this population as a valid species.

From all other Pulchriphyllium bioculatum -like species, Pulchriphyllium scythe stat. rev., comb. nov. females can be differentiated by their notably larger size (10.8 to 11.0 cm (vs the other Pulchriphyllium bioculatum -like species which range from 6.7 to 9.5 cm long). Females of Pulchriphyllium scythe stat. rev., comb. nov. are so large they actually fall within the size range of Pulchriphyllium giganteum (Hausleithner, 1984) (but can easily be differentiated by the mesopleural spination as Pulchriphyllium scythe stat. rev., comb. nov. does not have the notable medial projection like in Pulchriphyllium giganteum ). Male Pulchriphyllium scythe stat. rev., comb. nov. are poorly known (few males have been located in museum collections and few living observations have been located, coupled with the original male syntype specimen being lost), therefore, differences have been difficult to identify as consistent. At the moment the most notable feature we have been able to identify is that the profemoral exterior lobe appears to be slightly narrower than in most Pulchriphyllium bioculatum -like species, giving the exterior lobe a more obtuse angle appearance.

Distribution.

Thanks to iNaturalist (Figs 17 , 18 ) and review of museum collections, the distribution for this species is beginning to be clarified, as well as the geographic disconnect from the other " Pulchriphyllium bioculatum "-like species adjacent to this species range. At the moment we are aware of records for Pulchriphyllium scythe stat. rev., comb. nov. from India (provinces of Bengale Occidental, Assam, Nagaland, Meghalaya, Tripura, and Mizoram) and from the Slyhet division of Bangladesh (Fig. 15A ). This species is geographically separated by the drier Eastern Ghats, Deccan Plateau, and the Central Highlands from Pulchriphyllium anangu sp. nov. (which is found in the heavily forested and wetter southwestern India; Fig. 15A ). The geographic separation from Pulchriphyllium bioculatum from southern mainland Asia is not as clearly defined as there are some potential " Pulchriphyllium bioculatum -like" records from central Myanmar which would be useful to compare in a molecular phylogeny one day. A potential geographic barrier between the northern extreme of Pulchriphyllium bioculatum and Pulchriphyllium scythe stat. rev., comb. nov. is the high elevation Rakhine Mountains (Burmese: Rakhine Yoma).

Remarks.

The only remaining syntype female (Fig. 16 ) is herein designated as the lectotype. In the original description male and female morphology was described, suggesting that there were syntypes of both sexes (although the exact number of which were not recorded). Unfortunately, male specimens upon which the description was based could not be located within the OUMNH collection. If any male specimens or additional female specimens can ever be located, they should be considered paralectotypes.

Pulchriphyllium scythe stat. rev., comb. nov. is an uncommonly recorded taxon, which has mostly been recognized as a valid species by some authors, and as a synonym or subspecies/form by others ( Brock et al. 2022). Some of this confusion likely is due to the lack of examination of the type material, which has never been illustrated to date, and it appears that this taxon has not been extensively reviewed and compared with other populations by past authors. As the types have not yet been illustrated, they first had to be identified within the OUMNH collection (which received the F. W. Hope collection which the type specimens were deposited within ( Gray 1843)). Near one large female specimen was a label which reads "Possibly a ♀ Syntype of Phyllium scythe Gray. Only specimen with exactly correct size and locality data. C. O’Toole 13-xii-1979". We agree with this assessment by C. O’Toole and based upon the style of the label (Fig. 16D ) and the pin used for this specimen, this appears to match the era correctly. Unfortunately, even though at least one male syntype was described and noted by Gray (1843) as being within the same collection, a specimen could not be located which might be an original male. Unfortunately, any male specimens appear to be lost, but thanks to the remaining female specimen, to help remove uncertainty surrounding this species, we herein designate the female as the lectotype specimen for Pulchriphyllium scythe stat. rev., comb. nov. (Fig. 16 ).

Figures

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 16. Pulchriphyllium scythe (Gray, 1843) stat. rev., comb. nov. herein designated lectotype female, photographs by Robert Douglas (OUMNH) A habitus, dorsal B habitus, ventral C detail of the front leg, dorsal D data label E detail of the genitalia, ventral F detail of the antenna, head, and anterior of the thorax, dorsal.

Figure 17. Live females of Pulchriphyllium scythe (Gray, 1843) stat. rev., comb. nov. A adult female, dorsal habitus, found near Makunda Christian Hospital, Karimganj District, Assam, 20 April 2016, photographed by Vijay Anand Ismavel (India), (https: // www. inaturalist. org / observations / 4311333) B adult female, dorsal habitus, found in Assam 788727, India, 27 December 2017, photographed by iNaturalist user @ lovelymonlamin (https: // www. inaturalist. org / observations / 30552832) C adult female, dorsal habitus, found in Assam 788727, India, 27 August 2019, photographed by Dwithun Moshahary, (https: // www. inaturalist. org / observations / 51076352) D female nymph, dorsal habitus, found in Vaisam, Damchhara R. F., Tripura, India, 12 August 2020, photographed by Michael Lalruatfela (India) E female nymph, dorsal habitus, found near Makunda Christian Hospital, Karimganj District, Assam, 9 June 2019, photographed by Vijay Anand Ismavel (India), (https: // www. inaturalist. org / observations / 29119549) F same individual as in D but dorso-anterior view. Photographs used were uploaded to iNaturalist and are here used under license (CC BY-NC 4.0) or with explicit permission by the photographer.

Figure 18. Live males and nymphs of Pulchriphyllium scythe (Gray, 1843) stat. rev., comb. nov. A male habitus, dorsal, found in Vaisam, Damchhara R. F., Tripura, India, 30 June 2019 and photographed by Michael Lalruatfela (India) B male habitus, dorsal, found in Badshahi Forest, Assam, India, 18 September 2020 and photographed by Rejoice Gassah (India) (https: // www. inaturalist. org / observations / 64092851) C nymph, dorso lateral view, found in Lawachara National Park, 31 July 2019, photographed by Hassan-al Razi Chayan (Bangladesh) (https: // www. inaturalist. org / observations / 103359437) D nymph, dorso-anterior view, found in Dosdewa Khasi Village, Katamoni, Assam, India, 24 April 2021 and photographed by Rejoice Gassah (India) (https: // www. inaturalist. org / observations / 79254856). Photographs used were uploaded to iNaturalist and here used under license (CC BY-NC 4.0) or with explicit permission by the photographer.

Figure 21. Adult female profemoral lobes from various Pulchriphyllium species for comparison A Pulchriphyllium crurifolium stat. rev., comb. nov. (NHMUK) B Pulchriphyllium bioculatum from West Malaysia (Coll RC 16 - 038) C Pulchriphyllium scythe stat. rev., comb. nov. from Sylhet, Bangladesh (OUMNH) D Pulchriphyllium pulcrifolum from Java, Indonesia (Coll RC 16 - 024) E Pulchriphyllium bhaskarai sp. nov. from Java, Indonesia (MZPW).