Trolicaphyllium brachysoma (Sharp, 1898) Cumming & Tirant & Bu ̈ scher, 2021

Cumming, Royce T., Tirant, Ste ́ phane Le & Bu ̈ scher, Thies H., 2021, Resolving a century-old case of generic mistaken identity: polyphyly of Chitoniscus sensu lato resolved with the description of the endemic New Caledonia Trolicaphyllium gen. nov. (Phasmatodea, Phylliidae), ZooKeys 1055, pp. 1-41 : 1

publication ID

https://dx.doi.org/10.3897/zookeys.1055.66796

publication LSID

lsid:zoobank.org:pub:DB8C0779-E757-44ED-B9B2-397EA2EF3BAE

persistent identifier

https://treatment.plazi.org/id/E9E27569-68C8-57E5-93DD-2094FFFD0480

treatment provided by

ZooKeys by Pensoft

scientific name

Trolicaphyllium brachysoma (Sharp, 1898)
status

comb. nov.

Trolicaphyllium brachysoma (Sharp, 1898) comb. nov.

Figures 14 View Figure 14 , 22 View Figure 22 , 24 View Figure 24 , 25 View Figure 25

Material examined.

(35 ♀♀, 11 ♂♂, 2 unsexed nymphs): Syntypes (2 ♀♀): " Phyllium (Chitoniscus) brachysoma . Type D.S. Lifu. Dr. Willey. 1897" and " Phyllium brachysoma . Type ex parte. D. Lifu. Willey. 1897" (CUMZ; Fig. 22 View Figure 22 ). See Suppl. material 1 for additional specimens reviewed, their collection data, and depositories .

Remarks.

This was the first phylliid species recorded from New Caledonia and was therefore the first described Trolicaphyllium gen. nov. species, consequently, we here designate it as the type species for the new genus. Additionally, it was chosen as it has acceptably accurate collection data (Lifou Island; a rather small island instead of a general locality from the larger main island, which possibly contains several species) thereby removing some degree of possible confusion which could surround such old and difficult to distinguish specimens. This precise locality will allow future reviewers with adequate material sampled from numerous islands to identify species boundaries and determine if this species ranges across New Caledonia or if it is restricted to Lifou Island.

The syntype females were collected by Dr. Arthur Willey in 1897 while he was living on Lifou Island (Fig. 23 View Figure 23 ; Sharp 1898). Dr. Willey was traveling and living in New Britain, New Hanover, eastern New Guinea, and Lifou Island between 1895 and 1897 in search of living Pearly Nautilus colonies which he could capture, collect eggs from, and rear through development in order to study their embryology ( Wiley 1899; Kerr 1943). Although his years of expedition yielded many great discoveries of which he published prolifically, he was unfortunately unsuccessful in his primary goal of rearing eggs to maturity ( Willey 1899). Willey lived on the west coast of Lifou Island on "Sandal Bay" (modern Santal Bay) from July 1896 to March 1897; and while no exact date was given with the syntype set of females, they are noted as being collected in 1897. Therefore, they are from the beginning of the year (January through March), and most likely from late January when a severe gale passed through the area (wreaking havoc on his Nautili traps; Kerr 1943) which likely knocked the phylliids from the canopy enabling them to be found by Dr. Willey. While males occasionally will fly to lights at night, females and nymphs are most often only found on the ground after storms when they are knocked from their typical canopy habitat and found lower (Brock and Hasenpusch 2003, 2015).

No etymology was given by Sharp, but it can be assumed that he chose Trolicaphyllium brachysoma to denote the size of the species, from the Greek words brachy - (short) and - soma (body).

Differentiation.

For female Trolicaphyllium brachysoma comb. nov., one feature which appears to differentiate this species from the other two is the abdominal shape, which is lobeless, and tapered, giving them a spade-shaped appearance. It is worth noting however that in many phylliids abdominal shape is often a poor feature for differentiation as it is often variable within a single species ( Cumming et al. 2020b), and even in the syntype set of two females, one female is notably more tapered (Fig. 22B View Figure 22 ) than the other (Fig. 22A View Figure 22 ). Trolicaphyllium brachysoma , comb. nov. is about the same size as Trolicaphyllium sarrameaense comb. nov. (ca. 60 mm) which can differentiate them from Trolicaphyllium erosus comb. nov. which are notably smaller (ca. 40 mm).

Correctly matching up male and female phylliids is frequently a significant challenge due to their elusiveness in nature and sexual dimorphism and therefore opposite sexes can only be confirmed through molecular comparison or captive rearing ( Cumming et al. 2020c; Cumming et al. 2021). Unfortunately, we have yet to confidently confirm a male Trolicaphyllium brachysoma comb. nov. and therefore, at this time can only illustrate presumed males (Fig. 24 View Figure 24 ) which follow the morphology of the female by having a smooth tapered abdomen and falling within an appropriate size range for a potential male (38 to 43 mm). Trolicaphyllium erosus comb. nov. has no presumed male records we are aware of (as no possibilities have been located in collections which are small enough to represent a male of this species) but based upon female size the male Trolicaphyllium erosus comb. nov. is likely rather small.

Distribution.

The type locality for this species is Lifou island, but Trolicaphyllium brachysoma -like specimens with the tapered, lobeless abdomen have been found on Grande Terre (Fig. 21 View Figure 21 ) and L’Île-des-Pins (Fig. 25 View Figure 25 ) as well. Additionally, within the MNHN there is a female which was collected on Ile de Bélep, which is the only phylliid record we have seen from this island, and we only tentatively note this specimen as this species as it has slight lobes on the abdomen and could not be examined in person. Hopefully future molecular analyses with material from multiple islands will reveal if these are all one species or several.