Cryptophyllium athanysus (Westwood, 1859) Cumming & Bank & Bresseel & Constant & Tirant & Dong & Sonet & Bradler, 2021

Cumming, Royce T., Bank, Sarah, Bresseel, Joachim, Constant, Je ́ ro ̂ me, Tirant, Stephane Le, Dong, Zhiwei, Sonet, Gontran & Bradler, Sven, 2021, Cryptophyllium, the hidden leaf insects - descriptions of a new leaf insect genus and thirteen species from the former celebicum species group (Phasmatodea, Phylliidae), ZooKeys 1018, pp. 1-179 : 1

Cryptophyllium athanysus (Westwood, 1859) comb. nov. Figures 11 , 12

Material examined.

Very few specimens are known. We examined the holotype female in the NHMUK "Holo-type. Ceylon. Athanysus, Westw. Phyllium Athanysus Westw, Ceylon. BMNH(E) #845230" (Fig. 11A ) and a male in the OUMNH collection "P. Cryptophyllium athanysus , Westw. Ceylon. E Coll. (1830-73), W. W. Saunders., Purchased and, pres. '73 by Mrs. F. W. Hope." Greene (1906: fig. 1b, plate between page 220 and 221) illustrated a single female specimen as well as an egg (fig. 2b, page 221). We were unable to trace these specimens for proper examination. Besides these few specimens, we reviewed images of one live female (Fig. 12A, B ) and one live male (Fig. 12C ) from the Sinharaja Forest Reserve, but no other records> are known to us.

Remarks.

This rare species has only had a number of instances over the years where preserved specimens were illustrated. Here we present the first known photographs of live male and female individuals observed on two different occasions, both within the Sinharaja Forest Reserve, Sri Lanka (Fig. 12 ).

Differentiation.

Females can be differentiated by the smaller size (the smallest known species of Cryptophyllium gen. nov., ca. 77.0 mm) and the fully developed exterior metatibial lobes, which span the entire metatibial shaft, and the weak but notable full mesotibial exterior lobes, which also span the entire length of the shaft (when there are exterior lobes present in the other Cryptophyllium gen. nov. species, they are small and restricted to the distal end of the shaft only). Cryptophyllium athanysus comb. nov. females are most morphologically similar to Cryptophyllium bollensi sp. nov. and to Cryptophyllium chrisangi comb. nov. due to the anteriorly narrow mesopleura and the broad rounded profemoral exterior lobes. Additionally, Cryptophyllium chrisangi comb. nov. also has a tapered abdomen like Cryptophyllium athanysus comb. nov. without distinct abdominal lobes on segment VII, which many Cryptophyllium species have. Both of these morphologically similar species can immediately be differentiated however by the lack of metatibial exterior lobes.

Males can also be differentiated from all other species by the presence of fully developed exterior metatibial lobes which span the entire metatibial shaft, as no other Cryptophyllium gen. nov. species are known to have such a feature. Male Cryptophyllium athanysus comb. nov. are morphologically very similar to Cryptophyllium westwoodii comb. nov. as they both have similar narrow abdominal shapes, similar profemoral morphology, and similar thorax shape and serration. Cryptophyllium athanysus comb. nov. can be differentiated easily however by the presence of metatibial exterior lobes, which Cryptophyllium westwoodii comb. nov. lacks.

Distribution.

Sri Lanka. All old records> simply state “Ceylon’’ as the location, but the two modern records> we have come across were both from within the Sinharaja Forest Reserve on the southern end of the island (Fig. 12 ). Even Greene (1906) regarded this species as rarely encountered with most records> belonging to the other phylliid species present on the island.

Figures

Figure 11. Cryptophyllium athanysus comb. nov. holotype female, photographs by Paul Brock (NHMUK) A habitus, dorsal view B details of the thorax, dorsal C genitalia details, ventral D illustration of a Cryptophyllium athanysus comb. nov. egg from Greene (1906).

Figure 12. Live Cryptophyllium athanysus comb. nov. observed in the Sinharaja Forest Reserve, Sri Lanka A, B female photographed by Alberto Carrera (A photograph purchased from Alamy photo stock website B photograph purchased from Adobe Stock) C first record of a live male observed and photographed by Angela Christine Chua (Singapore) in January 2020.