Phyllium (Pulchriphyllium) Griffini, 1898

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 : 62-66

Phyllium (Pulchriphyllium) Griffini, 1898

According to table 10 above Pulchriphyllium (s. str.) differs from Phyllium Illiger by: the presence of exterior lobes on the tibiae of both sexes; triangular cross-section of antennomeres IV–VIII of ♀; shorter tegmina which at best reach to the posterior margin of abdominal segment II and ventrally pectinate or apically angulate antennomeres of ♂♂, as well as the lack of raised hairy or feather-like structures, conically raised operculum and distinct longitudinal lamellae in the eggs.

Based on morphological features of the insects and eggs as well as the geographic distribution four species-groups can be recognized within this subgenus. Only those species here comprised in the bioculatum species-group and schultzei species-group belong in Pulchriphyllium (sensu stricto). As already discussed above and emphasized in table 10 the systematic position of the closely related frondosum and brevipenne species-group is problematic, since they generally key out as Chitoniscus Stål, 1875 . They do hence not belong in Pulchriphyllium (s. str.) but are here provisionally attributed to this subgenus since their members share more features with this than they do with Phyllium .

1. Bioculatum species-group. Members of this group differ from all other species in the entire genus Phyllium by the prominent and broad exterior (dorsal) lobe of the tibiae, triangular cross-section of antennomeres IV–VIII of ♀, ventrally pectinate antennae of ♂♂ as well as the prominently conically raised operculum and lamellate longitudinal carinae of the eggs. The distribution extends from the Seychelles over India, Sri Lanka and the Andamans to S-China, Myanmar, Thailand, Laos, Vietnam, Peninsular Malaysia, Borneo and the Greater Sunda Islands. The only species contained are: Ph. bioculatum Gray, 1833 (including the doubtful synonyms from different localities – see comments below), Ph. giganteum Hausleithner, 1984 [Peninsular Malaysia] and Ph. sinense Liu, 1993 [S-China].

Some of the numerous synonyms of Ph. bioculatum Gray, 1833 established by various previous authors (see Otte & Brock, 2005: 275) and based on material from far distant and well separated localities appear unjustified and very doubtful. Hence, the present treatment of the “ bioculatum -complex” seems highly inaccurate and the systematics of this species-complex are obviously still poorly understood. In fact, several of the current synonyms of Ph. bioculatum appear to be well defined sub-species, which constantly differ from the typical form found in Peninsular Malaysia, Singapore and Sumatra by morphological features of the insects and eggs and are furthermore well separated geographically. Although the type-locality of Ph. bioculatum is unknown, the ♂ HT best matches with material from the mentioned regions. Some of the differences were illustrated and summarized by Grösser (2001 & 2008), but the author has unfortunately not drawn any consequences from his observations. For instance, the distinctive form described as Ph. pulchrifolium Audinet-Serville, 1838 (= Ph. magdelainei Lucas, 1857 ) and found on Java and Sumatra, differs from all other known varieties of Ph. bioculatum by: the very broad abdomen (only about 1.3x longer than wide); very broadly rounded, excavated and posteriorly extending abdominal segment VIII; two small transparent eye-like spots at the anterior margin of abdominal segment IX; broad and transverse mesopraescutum (see table 12) and acutely pointed apex of the subgenital plate of ♀, as well as very broad and acutely angular (angle ca. 90°), basally irregularly excavated exterior lobe of the profemora, and shape of the abdomen of ♂♂ with segments V–VI gradually widening, VII widest and VIII prominently rounded, excavated and extending posteriorly. So, at least this form may rank as a well defined sub-species.

Four possible sub-species of Ph. (Pu.) bioculatum Gray, 1833 are: 1) Ph. bioculatum bioculatum Gray, 1833 [Peninsular Malaysia, Singapore], 2) Ph. bioculatum agathyrsus Gray, 1843 [ Sri Lanka and SE-India], 3) Ph. bioculatum pulchrifolium Audinet-Serville, 1838 [Java & Sumatra] and 4) Ph. bioculatum crurifolium Audinet-Serville, 1838 [ Seychelles]. Although constant morphological differences are present in the insects and eggs, DNA-analyses might become necessary for any broader discussion and hopefully such forthcoming data will help solving the status of these synonyms or sub-species respectively.

2. Schultzei species-group. The only species contained are the New Guinean Ph. schultzei Giglio-Tos, 1912 and Ph. exsectum Zompro, 2001 , whose ♀ share the presence of two rounded exterior lobes on the protibiae and shortened tegmina which merely reach to abdominal segment V. The only features which place these two distinctive species in the subgenus Pulchriphyllium are the presence of exterior lobes on the protibiae and apically angulate club-like (not distinctly pectinate ventrally as stated by former authors) antennomeres of ♂♂ of Ph. (Ph.) schultzei (those of Ph. (Ph.) exsectum are not known).

Both species differ from representatives of the bioculatum species-group by the presence of two (!) small rounded exterior lobules on the protibiae (a single large lobe in the bioculatum species-group), and conspicuously shortened tegmina of ♀ which project no further back than abdominal segment V. Furthermore, both sexes at best have one or two small, tooth-like exterior (dorsal) lobes on the meso- and metatibiae (a single large lobe in the bioculatum species-group). The short tegmina of ♂♂ which hardly reach the posterior margin of abdominal segment II are shared with the bioculatum species-group. Although both species in several aspects resemble representatives of the frondosum species-group, they differ by the considerably larger size (♀> 80 mm) and strongly trapezoidal meso-praescutum, which is roughly equal in length to the width of the anterior margin (distinctly wider than long in the frondosum species-group). The shape of abdominal segments VI–VIII in ♂♂ of Ph. (Ph.) schultzei is seen to be strongly variable, a ♂ in DEIC having them distinctly excavated and lobed (see Grösser, 2008: 133, fig. 156) while they are not excavated in a ♂ in MNHU.

FIGURES 95–112. Eggs [scale = 1 mm]

95–96. Ph. (Ph.) celebicum de Haan, 1842 , 95. dorsal, 96. lateral

97–98. Ph. (Ph.) westwoodii Wood-Mason, 1875 , 97. dorsal, 98. lateral

99–100. Ph. (Ph.) ericoriai n. sp., 99. dorsal, 100. lateral

101–102. Ph. (Ph.) gantungense n. sp., 101. dorsal, 102. lateral

103–104. Ph. (Ph.) mindorense n. sp., 103. dorsal, 104. lateral

105–106. Ph. (Ph.) hausleithneri Brock, 1999 , 105. dorsal, 106. lateral

107–108. Ph. (Ph.) jacobsoni Rehn & Rehn, 1933 , 107. dorsal, 108. lateral

109–110. Ph. (Ph.) mabantai n. sp., 109. dorsal, 110. lateral

111–112. Ph. (Ph.) philippinicum n. sp., 111. dorsal, 112. lateral

Eggs of the schultzei species-group are not known.

3. Frondosum species-group. Members of this group are well distinguished from those of the two previous ones, the bioculatum and schultzei species-groups, by the distinctly transverse meso-praescutum and lack of a distinct, broad dorsal lobe on the meso- and metatibiae (at best with a single, small triangular tooth). The eggs differ by lacking longitudinal lamella-like extensions of the capsule and have the operculum at best slightly conical. All species are rather small with ♀ ranging from 57.0–79.0 mm in body length. The six closely related species that fall into this group are: Ph. asekiense Grösser, 2002 [New Guinea], Ph. chitoniscoides Grösser, 1992 [New Guinea] n. comb., Ph. frondosum Redtenbacher, 1906 [New Guinea] n. comb., Ph. groesseri Zompro, 1998 [ Solomon Islands], Ph. keyicum Karny, 1914 [Key Islands] n. comb. and Ph. suzukii Grösser, 2008 [ Moluccas]. Although they lack exterior lobes on the tibiae Ph. chitoniscoides , Ph. frondosum and Ph. keyicum are here transferred from the subgenus Phyllium , since they are without any doubt very closely related to the other two species contained and match with these in all key-features.

Ph. insulanicum Werner, 1922 was described from Toeal Island (Key Islands) the type-locality of Ph. keyicum Karny, 1923 . Unfortunately, the type of the latter species is presumed lost ( Otte & Brock, 2005: 274), but comparison of the HT of Ph. insulanicum with a good number of specimens of Ph. keyicum in NHMW, SMNS and the first author’s collection (coll. FH) leave no doubt it is the same species (n. syn., n. stat.). As in other species of the genus there is considerable variation in the shape of the abdomen, but segments VII–IX in particular, is seen in ♀. Klante (1976: 61) erroneously synonymised Ph. insulanicum with the smaller and sufficiently distinct New Guinean Ph. frondosum Redtenbacher, 1906 , a mistake that has remained unrecognized by all subsequent workers. It is here removed from synonymy with Ph. frondosum and synonymised with Ph. keyicum . Apart from a well separated distribution in the Key Islands (Wallacea) ♀ of Ph. keyicum differ from Ph. frondosum by: the larger dimensions (body length 70–79 mm compared to 62–66 mm for frondosum ); less angulate and not posteriorly extending exterior lobe of the profemora which has the outer margin almost unarmed (with distinct teeth in frondosum , Fig. 124 ); much more slender meso- and metafemora ( Fig. 125 ), which have the interior (ventral) lobe more slender and not as roundly expanded as in frondosum ; less granulose posterior portion of the head and slightly more slender antennae ( Fig. 129 ).

Due to the distinctly transverse meso-praescutum and presence of a prosternal swelling all six species in fact key out as Chitoniscus Stål, 1875 , if the keys provided by Zompro & Grösser (2003: 131) are strictly followed. The close relation between representatives of the frondosum species-group and Chitoniscus is even more strikingly emphasized by Ph. chitoniscoides , whose ♀ strongly resemble certain species of Chitoniscu s and also have the prosternal swelling conically raised and spiniform as in Chitoniscus . Using the keys provided by these authors Ph. chitoniscoides would directly key out as Chitoniscus , but the broad and angulate exterior lobes of the profemora and very broad interior (ventral) lobe of the mesofemora clearly indicate close relation to species in the frondosum species-group and place Ph. chitoniscoides therein. This is also confirmed by the angular eggs, which very well match with other known eggs of the frondosum speciesgroup. In general, the eggs are very similar to those of Chitoniscus and again emphasize the close relation to this genus, being rather small, angular and having a just slightly conical or knob-like operculum. All lack hairy structures on the capsule or operculum.

A further indication for a close relation to Chitoniscus is represented by the eastern but rather nearby geographic distribution of the six species here contained. They are restricted to New Guinea and neighbouring islands in the Wallacea ( Moluccas and Key-Islands) and Melanesia ( Solomon Islands), while Chitoniscus is distributed more east and southward in the Polynesian subregion ( Fiji, New Hebrides and New Caledonia).

4. Brevipenne species-group. This only contains the remarkable Ph. brevipenne Grösser, 1992 described from the Komba District, New Guinea. The transverse meso-praescutum and broad anteroventral lobes of the meso- and metafemora show very close relation to the frondosum species-group, but it is at once distinguished from these and all other species in the entire genus Phyllium by the strongly reduced, scale-like and almost circular tegmina (diameter only 9.0 mm) as well as the long abdomen of ♀. ♂♂ and eggs are not known.

113. Ph. (Ph.) celebicum de Haan, 1842

114. Ph. (Ph.) westwoodii Wood-Mason, 1875

115. Ph. (Ph.) ericoriai n. sp.

116. Ph. (Ph.) gantungense n. sp.

117. Ph. (Ph.) jacobsoni Rehn & Rehn, 1933

118. Ph. (Ph.) hausleithneri Brock, 1999

Figures

FIGURES 124–130. Species of the frondosum species-group and the genus Chitoniscus Stål, 1875 124. Ph. (Pu.) frondosum Redtenbacher, 1906, ♀ (PNG, Morobe Prov.) [coll. FH, No. 0413-1]