Phyllium (Phyllium) westwoodii Wood-Mason, 1875

Hennemann, Frank H., Conle, Oskar V., Gottardo, Marco & Bresseel, Joachim, 2009, On certain species of the genus Phyllium Illiger, 1798, with proposals for an intra-generic systematization and the descriptions of five new species from the Philippines and Palawan (Phasmatodea: Phylliidae: Phylliinae: Phylliini) 2322, Zootaxa 2322 (1), pp. 1-83 : 16-21

Phyllium (Phyllium) westwoodii Wood-Mason, 1875

( Figs. 6–10 , 20–23, 26–27 , 86 , 97–98, 114, 137–138)

Phyllium westwoodii Wood-Mason, 1875: 218 , pl. 17 (♀). ST, ♀: South Andaman, Port Blair, leg. Captain Protheroe (NZSI); ST, ♂: Burmah [= Myanmar], Salween county, 150 miles north of Moulmein, Pahpoon, leg. W. Davidson (NZSI – lost). Kirby, 1904: 423. Dossey, Gottardo, Whitaker, Roush & Edison, 2009: 861.

Phyllium (Phyllium) westwoodii, Liu, 1993 , 206, figs. 6 & 7 (♀). Grösser, 2001: 98, fig. 126 (♀). Zompro & Grösser, 2003: 136, 138, 139. Otte & Brock, 2005: 275. Grösser, 2008: 141, fig. 176 (♂, ♀).

Phyllium (Phyllium) westwoodi, Wood-Mason, 1877: 351 , pl. 3: 3 (♂) [Illustration of ♂ ST from Myanmar]. Klante, 1976: 64, figs. 5–7 (♀). Hennemann, Conle & Zhang, 2008: 25.

Chen & He, 2008: 368, fig. 327a–b (♀).

Phyllium celebicum, Wood-Mason, 1875: 218 , pl. 16 (♀ & nymph).

Kirby, 1904: 423 (in part).

Redtenbacher, 1906: 175 (in part).

Grösser, 1990: 199, 200. [Defensive glands]

Hennemann, 1992: 31, figs. 1–3. [Culture report]

Sorpongpaisal &Thanasinchayakul, 2006: 22.

Phyllium celebicum var., Deschandol, 1991: 10, figs.

Grösser, 2001: 64, figs. 16, 41–44 & 82–87.

Zompro & Grösser, 2003: 136, 138, 139 & fig. 12: 3 (egg).

Grösser, 2008: 103, figs. 24, 34, 52–55, 122–127, 187 & 195.

Phyllium siccifolium, Redtenbacher, 1906: 176 (in part – only the ♂ from Siam [= Thailand] in NHMW)

Phyllium siccifolium var. westwoodi, Redtenbacher, 1906: 176 . [Erroneous synonym]

28: ♀ HT: Palawan ( Mount Gantung ) [ MSNG]

29: ♀ PT: Palawan ( Mount Gantung ) [coll. MG]

30: ♂ PT: Palawan ( Mount Gantung ) [ MSNG]

Material examined [ 20 ♀, 22 ♂♂, 2 nymphs, eggs]: THAILAND : 1 ♀: N-Thailand, River Ping , Lamphun, 22.VIII.1996 (coll. FH, No 0542-3) ; 10 ♂♂, 2 ♀, 1 ♀ (nymph n3), eggs: ex Zucht F. Hennemann, Thailand, 1995-2001, PSG No. 128 (coll. FH, No’s 0542-1, 2, 4 to 14, E, MP1 & MP2); 2 ♂♂, 2 ♀: ex Zucht: F. Hennemann, Herkunft: Thailand, Chiang Mai, PSG No. 128, 2005-2007 (coll. FH, No’s 0542-15 to 18) ; 1 ♂, 1 ♀: N-Thailand, Chiang Mai, X.2007 (coll. FH, No’s 0542-19 & 20) ; 2 ♂♂, 1 ♂ (penultimate instar): ex Zucht 2000, Zuchtstamm aus Thailand (coll. OC, No’s 01821 & 01822); 1 ♂, 1 ♀: Nord-Thailand , Chiang Mai, 1987, ex Coll. Lehmann (coll. OC, No. 01824) ; 1 ♀: Nord-Thailand, Chiang Mai, 08.2002 (coll. OC, No. 01825) ; 3 ♂♂, 3 ♀: N-Thailand, Chiang Mai, X.2007 (coll. OC) ; 1 ♂: Coll. Br. v. W., Siam, Sandreczki leg.; det. Redtenb. Phyllium siccifolium ; 20.349 ( NHMW, No. 296) ; 1 ♂, 2 ♀, eggs: reared by M. Gottardo 2006- 2008; origin: Thailand, Chiang Rai, leg. C. Sinhabaedya (coll. MG) .

LAOS: 2 ♀: Coll. Br. v. W., Luang-Prabang, Laos; det. Redtenb. Phyllium celebicum ( NHMW, No. 293) .

KAMPUTCHEA: 4 ♀, 1 ♂: Cambodja, Cochinchina, Coll. Vitalis ( MNCN) .

MALABAR: 1 ♀: Malabar, Melig [in error?] ( MNHU) .

Comparison: Distinguished from the very similar Ph. (Ph.) celebicum de Haan, 1842 from Sulawesi and Ambon by: the broader, less elongate mesonotum which is only about 1.5x longer than wide (almost 2x in celebicum ); smaller, semi-circular to roundly angular exterior lobe (angle> 90°) and less numerous and prominent teeth of the interior lobe of the profemora ( Figs. 20–21 ); shorter, more robust and differently structured antennae ( Fig. 86 ), which have the apical antennomere hardly longer than the previous and III with only 50–56 teeth in the pars stridens (38–44 in celebicum ); longer alae which are roughly ¾ the length of the tegmina (only about half the length in celebicum ), and longer subgenital plate which has the apex protruded into a slender spiniform projection ( Fig. 26 ). ♂♂ also differ by: the broader and shorter meso-praescutum; smaller and just gently rounded exterior lobe and less distinct armature of the interior lobe of the profemora ( Fig. 22–23 ); two terminal hooks of the vomer (only one in celebicum ) as well as the different more or less oval abdomen and lack of eye-like spots in abdominal segment VI. In addition to features mentioned for adults, nymphs of both sexes can frequently be distinguished from those of celebicum by having only the usual two conspicuous eye-like spots in abdominal segment V. Eggs are also similar to those of celebicum but differ by: the smaller dimensions; flattened lateral surfaces of the capsule, which have the circular pits smaller and less deep; shorter micropylar plate and longer hairy structures of the capsule and operculum (Figs. 97– 98).

Other similar and certainly closely related species from neighbouring regions are: Phyllium (Phyllium) athanysus Westwood, 1859 from Sri Lanka, Ph. (Ph.) rarum Liu, 1993 from Guangxi, S-China and Ph. (Ph.) parum Liu, 1993 from Hainan, S-China. All three species are only known from a single sex, the first two from the ♀ and the latter one from the ♂♂. ♀ of Ph. (Ph.) westwoodii differ from Ph. (Ph.) athanysus by the greater size, broader abdomen (segments VI and VII in particular), broader and shorter meso-praescutum, more prominently armed mesopleurae and lack of dorsal lobes on the meso- and metatibiae, and from Ph. (Ph.) rarum merely by the considerably broader and more angulate abdomen and longer tegmina. The egg of Ph. (Ph.) athanysus was described and illustrated by Green (1906) and is very similar to that of Ph. (Ph.) westwoodii , however clearly distinguished by the much smaller dimensions. From the very similar Ph. (Ph.) parum ♂♂ appear to differ by the shorter alae and broader, posteriorly rounded poculum.

Diagnosis: ♀ ( Figs. 6–9 , 137 ). Medium-sized to large for the subgenus (body length 70.0–101.0 mm) with a moderately broad to broad and rounded to angulate abdomen (maximum width 28.0–42.0 mm), large semi-circular exterior lobes of the profemora, and well developed alae which are almost ¾ the length of the tegmina (21.0–42.0 mm). Colouration variable, ranging from green to yellow with the body and legs to variable degree furnished with brown speckles or mottling; more rarely pale brown specimens may occur. Head broad with the cheeks moderately convex; vertex smooth. Antennae rather short and broad (4.0– 4.4 mm), shorter than postocular section of head capsule. Apical antennomere (IX) very short and hardly longer than VIII. Pars stridens on antennomere III with 50–56 teeth ( Fig. 86 ). Pronotum trapezoidal and narrowed towards the posterior with anterior margin about 2x broader than posterior margin; the latter slightly truncate. Meso-praescutum almost parallel-sided and about 1.2x longer than wide. Lateral margins armed with a variable number of rather small, but differently sized spiniform tubercles, 3–4 of which are slightly enlarged. Disc with a ± decided longitudinal median carina and irregularly set with granules in anterior portion. Anterior margin with a short but curved transverse ridge. Mesopleurae narrow in anterior portion and the posterior 2/3 prominently diverging; lateral margins irregularly armed with spiniform tubercles of variable sizes. Mesosternum very slightly tectiform longitudinally and with a few granules in anterior portion, posterior half smooth. Tegmina projecting over anterior margin of abdominal segment VII. Alae well developed, roughly ¾ the length of tegmina and ± reaching half way along abdominal segment VI (21.0–42.0 mm). Abdominal segments II–III gradually widened, IV acutely angulate and V–VI parallel-sided to very slightly narrowing. VII variable, ranging from widely rounded to acutely angulate (roughly 90°) and occasionally protruded into a rounded lobe which extends posteriorly ( Figs.6–9 ). Subgenital plate acutely triangular and with an elongate, narrow apex which reaches about half way along tergite X ( Fig. 26 ). Profemora with a large ± semi-circular to roundly angular exterior lobe (angle <90°), outer margin very minutely and sparsely denticulate. Exterior lobe distinctly wider than interior lobe, the armature of the latter variable ( Figs. 20–21 ). Interior lobe of protibiae prominently deflexed and roundly triangular (angle> 90°). Interior lobe of mesofemora gently rounded and narrower than exterior lobe; the latter more decidedly rounded to slightly angular. Protarsus about 2/3 the length of corresponding tibia, probasitarsus roughly 4.5x longer than wide.

♁♁ ( Figs. 10 , 138 ). Large for the subgenus (body length 63.5–69.8 mm) with a moderately broad and oval abdomen (maximum width 13.5–19.3 mm). Colouration pale to mid green, to a variable degree furnished with brown speckles and markings. Antennae pale cream, straw or green with the two apical antennomeres mid to dark brown. Vertex smooth. Antennae consisting of 26–27 segments and projecting over posterior margin of abdominal segment III. Pronotum and mesothorax structured like in ♀. Meso-praescutum only about 1.6x longer than wide. Mesopleurae narrow in anterior portion but distinctly diverging in posterior 2/3, lateral margins irregularly but minutely tuberculose. Mesosternum with a longitudinal median keel and minutely granulose in posterior half. Tegmina reaching about half way along abdominal segment III, alae reaching segment X. Abdominal segment II roughly parallel-sided, III–V slightly widening and VI to X gradually narrowing, V widest segment. V with two conspicuous transparent eye-like spots. Vomer broadly triangular and with two short terminal hooks of which the dextral one is smaller; both curved towards the right. Poculum moderately convex with a fine longitudinal carina in posterior portion and reaching about 1/3 the way along tergite X ( Fig. 27 ). Exterior lobe of profemora rather broad for the subgenus, widely rounded but not angulate; outer margin with a few small dentations in anterior portion. Armature of interior lobe variable ( Figs. 22–23 ). Exterior lobe at least equal in width to interior lobe but usually slightly broader. Protibiae with a rather narrow, roundly triangular interior lobe. Exterior and interior lobe of mesofemora roughly equal in width. Protarsus about 2/3 the length of corresponding tibia, probasitarsus roughly 5x longer than wide.

Nymphs: Newly hatched nymphs are rather small (body length 12–13 mm) with a slender abdomen (width 1.8 mm). General colour dark rusty-red with white sports on the legs, the meso- and metafemora each having two conspicuous white spots sub-basally. Abdominal segments II–VII each with a bold pale green marking. Basitarsi are pale green.

Eggs (Figs. 97–98). Of moderate size, strongly angular and with distinct parallel longitudinal keels, two dorso-laterally and three ventrally. Capsule about 1.8x longer than wide, the dorsal and lateral surfaces flattened, the dorsal surface tectiform; polar-area slightly concave. Almost entire capsule surface irregularly covered with moss or hair-like appendages; these particularly numerous and most prominent along the longitudinal keels of the capsule and on operculum. Capsule otherwise set with several deep circular pits of variable sizes, roughly arranged in longitudinal rows. Micropylar plate elongate, about ¾ the length of capsule and tapered towards both ends; outer margin set with hairy structures. Micropylar cup placed slightly below centre of plate. Operculum roundly conical, almost circular in cross-section and displaced towards ventral egg surface; opercular angle about 20°. Lateral surfaces with several deep circular impressions. Colouration pale to dark brown, the moss-like structures slightly paler than rest of capsule.

Measurements [mm]: length (including operculum) 4.6–4.8, length 4.1–4.3 mm, width 2.4–2.6 mm, height 3.0– 3.2 mm, length of micropylar plate 3.2–3.3 mm.

Variation: This species shows considerable variation in the colouration, length of the tegmina and shape of the profemora and abdomen. In ♀ the colouration usually varies from very pale through mid to dull green, but more rarely yellow or pale brown specimens occur some of which may be attractively speckled with darker brown. Green specimens are mostly plain in colouration, rather rarely possessing brown speckles or markings on the tegmina and along the outer margins of the legs and abdominal segments. ♂♂ are usually plain pale to mid green, occasionally with more or less numerous and distinct brown speckles on the legs and along the exterior margins of the abdomen. Considerable variation is seen in the shape of the abdominal segments VI and VII of ♀. These may be either roundly narrowed (♀ ST from South Andaman, Fig. 6 ) or widely rounded (e.g. the ♀ from Lamphun and Chiang Mai, coll. FH & OC, Fig. 7 ). Other specimens have segment VI parallel-sided and VII roundly angular (e.g. the ♀ illustrated by Wood-Mason, 1875, pl. 17) or even posteriorly protruded into a rounded lobe which slightly extends over the posterior margin of segment VIII ( Fig. 8 ). In ♂♂ the abdomen (excluding median segment) ranges from being 2x to 3x the longer than wide. The shape of the exterior lobe of the profemora is strongly variable as well, in ♀ ranging from widely rounded (♀ ST from South Andaman) over semi-circular ( Fig. 20 ) to roundly angular ( Fig. 21 ) but always being> 90°. In general ♀ with a slender abdomen also have a slender exterior lobe of the profemora and vice versa. The number of teeth on the pars stridens of antennomere III in ♀ ranges from 50–56 ( Grösser, 2001: 17).

Comments: Wood-Mason (1875: 218) originally described Phyllium westwoodii based on a ♀ from South Andaman (Port Blair) and a ♂ from Myanmar (Salween County, Pahpoon). Wood-Mason (1875, pl. 17) provided an illustration of the ♀ and of the ♂ subsequently ( Wood-Mason, 1877, pl. 3: 3). Both syntypes are believed to have been originally deposited in NZSI, but only one has been traced in this institution and the other specimen must hence be regarded lost.

In the second publication Wood-Mason (1877: 351) stated to have examined a series of specimens of both sexes including nymphs from Malewoon in the Mergui District of Central Myanmar, which the author said were “…proving that I had correctly paired my insects on structural grounds alone”. The ♀ and ♀ nymph from Karen County ( Myanmar) which Wood-Mason (1875: 218, pl. 16) believed to be Phyllium celebicum de Haan, 1842 merely represent a variety of Ph. (Ph.) westwoodii , which has the exterior lobes of the profemora and abdominal segments VI and VII more widely expanded, than the ♀ ST of Ph. westwoodii from South Andaman (1875, pl. 17). In fact, examination of further material and captive breeding has shown these features lie within the range of variability of this species and the specimens that Wood-Mason had at hand represented the two opposite extremes, the ♀ ST from South Andaman being a very slender specimen and the ♀ from Karen County, Myanmar a very broad one.

Redtenbacher (1906: 176) erroneously interpreted Ph. westwoodii as a variety of Ph. siccifolium (Linné, 1758) , which was revised by Klante (1976: 64). The latter author well recognized the distinguishing features that separate Wood-Mason’s species from Ph. (Ph.) siccifolium and recorded specimens from Sumatra (Bokri- Deli) and the Riouw Islands south of Singapore. Subsequently, Ph. (Ph.) westwoodii has been frequently mentioned as a valid species in all comprehensive studies or catalogues of the genus ( Grösser, 2001 & 2008; Zompro & Grösser, 2003; Otte & Brock, 2005), but almost all available material (mainly cultured specimens originating from Thailand) was erroneously attributed to Ph. (Ph.) celebicum de Haan, 1842 , a result of the misinterpretation by Wood-Mason (1875).

Careful comparison of specimens from Thailand, Laos and Kamputchea leave no doubt that this species is not Ph. (Ph.) celebicum . This is seen in e.g. the relatively longer alae, longer and more acute subgenital plate, smaller and less angulate exterior lobe of the profemora, and shorter, differently structured antennae which have 50–56 teeth on the pars stridens (38–44 in celebicum ). In fact, captive reared ♂♂ match perfectly in every aspect with Wood-Mason’s ♂ ST from the Salween County in S-Myanmar ( Wood-Mason, 1877, pl. 3: 3), and the ♀ from Lamphun in N-Thailand (coll. FH) matches almost perfectly with the ♀ ST from South Andaman. Concerning the shape of the profemora and abdomen, captive reared ♀ are usually similar to the variety that Wood-Mason (1875: 218 , pl. 16) described and illustrated as “ Phyllium celebicum ”.

Grösser (1990) discussed the defensive glands of this species, and other papers (e.g. Hennemann, 1992) have dealt with the biology and captive breeding including brief descriptions and illustrations of the insects and eggs. Numerous colour photographs of various live insects were presented by Grösser (2001 & 2008), however all these publications erroneously refer to “ Phyllium celebicum ”.

* according to Klante (1976: 64)

Distribution ( Fig. 114 ): South Andaman Island (Port Blair [type-locality]); Myanmar (Salween County: Papun [type-locality], Mergui District: Malewoon [ Wood-Mason, 1877: 351], Karen County [ Wood-Mason, 1875: 218, as “ celebicum ”]); N-Thailand (River Ping, Lamphun [coll. FH] & Chiang Mai [coll. FH] Chiang Rai [coll. MG]); Laos (Luangprabang [ Redtenbacher, 1906: 176, as “ celebicum ”, NHMW & MNHN]); S- Kamputchea (“ Cochinchina ” [MNCN]); Vietnam (Bang-Taxeng [ Redtenbacher, 1906: 176, as “ celebicum ”]); S-China (Yunnan Province 1000 m [ Liu, 1993: 206]; Sumatra (Bokri-Deli [ Klante, 1976: 64, RMNH]); St. John’s Island near Singapore [ Klante, 1976: 64, FRIM] and Riouw Archipelago (Benton-Riouw (= Bintan) Island near Singapore [ Klante, 1976: 64, RMNH]).

The record from Vietnam by Redtenbacher (1906: 176) is doubtful and since omitted from the distribution map ( Fig. 114 ). “Malabar”, which refers to the southeast coast of India, for a specimen in MNHU is doubtful and here regarded erroneous, hence also omitted from the distribution map. “Bang Taxeng” is in fact a village situated in Ka’s County, N-Myanmar. The Sumatran record “Bokri-Deli” could not be found and is hence indicated on the map by an ellipse, as is the inexact “ Cochinchina ” [= Viet Nam].

Figures

FIGURES 6–10. Phyllium (Ph.) westwoodii Wood-Mason, 1875 [scale = 10 mm]

FIGURES 13–27. Left profemur and genitalia of members of the “celebicum-group” [scale = 2 mm].

FIGURES 85–94. Right antenna of ♀, interior view [scale = 1 mm]

FIGURES 137–140. Live Insects

FIGURES 113–118. Maps showing the distribution of Phyllium spp.