Tisamenus draconinus ( Westwood, 1848 )

Hennemann, Frank H., 2025, A taxonomic review of Philippine Obrimini stick insects: The genus Tisamenus Stål, 1875 (Insecta: Phasmatodea: Heteropterygidae: Obriminae), Faunitaxys 13 (24), pp. 1-85 : 33-36

Tisamenus draconinus ( Westwood, 1848)

( Fig. 17-19, 46 K-L)

Phasma (Pachymorpha) draconinum Westwood,1848:78 ,pl.38:5(♀).

LT, ♀: Philippine islands , 42-22 (Purch. Mr. Cuming); Co-Type Westwood, Phasma (Pachymorpha) draconinum ; Type Orth: 493, Phasma (Pachymorpha) draconinum Westw. [UMO, No.493];

PLT, ♂: Co-Type Westw.; Philippine islands , 42-22 (Purch. Mr. Cuming);

Phasma Acanthoderus draconinus Westw. ; Type Orth:493, Phasma (Pachymorpha) draconinum Westw. [UMO, No. 493].

Acanthoderus draconinus, Westwood, 1859: 52 .

Hoploclonia draconina, Stål, 1875: 93 .

- Redtenbacher, 1906: 45.

- Rehn & Rehn, 1939: 468. ( Draconinus Group)

- Cai, 1987: 26.

Tisamenus draconina, Bruner, 1915: 230 .

- Zompro, 2004: 206.

- Otte & Brock, 2005: 335.

- Brock & Büscher, 2022: 521.

- Hennemann, 2023b: 128.

Tisamenus draconinus, Kirby, 1904: 399 .

Hoploclonia draconia, Bragg, 1995: 27 . (Lectotype designation - Misspelling of draconinus ).

[Not: Hoploclonia draconina, Matsumura & Hirayama, 1932 : fig. Misidentification relating to T.napalaki n. sp.]

[Not: Hoploclonia draconina, Shiraki, 1935: 24 (Remark: Identification doubtful). Misidentification relating to T.napalaki n. sp.]

[Not: Hoploclonia draconina, Chen & He, 2008: 360 , pl. 4: 4. Misidentification relating to T. napalaki n. sp.]

[Not: Hoploclonia draconia, Huang, 2002: 84 , figs (Misspelling of draconinus ). Misidentification relating to T. napalaki n. sp.]

[Not: Hoploclonia draconia, Xu, 2005:335 (Misspelling of draconinus ). Misidentification relating to T.napalaki n. sp.]

Material examined

1 ♀, 1 ♂: Philippinen, Ost Luzon Island, Provinz Aurora, Sierra Madre , Dingalan , 230 m, local collector, IV.2012 [ FH 1104-1 & 2] ;

1 ♀, 2 ♂, 1 egg: Philippinen, O Luzon Id., Prov. Isabela, Sierra Madre, Cagayan Valley, Palanan, local collector II.2011 [ FH, No’s 1104-3 to 5, E1] ;

1 ♀, 1 egg: Philippinen, Polillo Island , local collector III.2011 [ FH, No. 1104-6, E2] ;

2 ♂ (immature): Coll. R.I.Sc.N.B., Philippines, E Luzon, Isabela, San Pablo , IX.2014, local collector, I. Lumawig [ RBINS] ;

1 ♀, 2 ♂: Coll. R.I.Sc. N.B., Philippines, Luzon , Cagayan, leg. T. Heitzmann [ RBINS] ;

18 ♀, 23 ♂, 12 egg (ex ovipositor):ex Zucht F. Hennemann 2024,Herkunft: Philippinen, N-Luzon, Prov. Cagayan, Peñablanca Munip., nr. Callao Cave [ FH, No’s 1104-7 to 47 & E3] ;

5 ♂, 1 ♀, 2 ♀ (immature): Ripang, Apayo, Luzon Island , P.I.; W. Boettcher Feb. 1918 [ ANSP] ;

1 ♂: Philippinen, Eastern Visayas, Prov. Leyte, Leyte Island , Mahaplag Munip., local collector VI.2012 [ FH, No. 1104-48] .

Differentiation. – This new species shows the closest affinity to T. napalaki n. sp. with which it shares the four large mesopleural spines. It is however distinguishable by the notably smaller dimensions and slightly stockier shape of both sexes and generally having the body armature less pronounced with all the major spines comparatively shorter and stouter and having only one metapleural lateral instead of two like in napalaki ( Fig. 17A, 19A). Males may also be distinguished from those of napalaki by the more evident mesothoracic constriction at the 3 rd mesopleural lateral, lack of the characteristic gibbous dorsal swelling of abdominal terga II-V and much smaller pair of posteriors on terga II-III as well as the more distinct ventro-basal swelling of the meso- and metafemora ( Fig. 19 HI) and having only three rather uniformly spaced teeth on the two ventralcarinae of the metatibiae ( Fig.19H).The eggs ( Fig. 46 K-L) are smaller but bulgier than those of napalaki , and readily differ by the much less sculptured capsule surface and larger but more overall narrower micropylar plate, which is about seven-eighths the length of the capsule (only about three-quarters the length of capsule in napalaki ) and has all three extensions notably longer and slenderer than in napalaki .

Variability. – This species shows noteworthy variability in aspect of the size, basically all elements of head and body armature as well as the colouration. The general colour ranges from rather uniformly dark brown (e. g. the lectotype ( Fig. 17I) and ♀ from Palanan and Polillo ( Fig. 17 D-E)) over various tones of brown, buff and ochre. Some ♀ are buff or ochre dorsally with only the thoracic pleurae and lateral surfaces of the abdomen darker brown, a colour pattern that is not seen in ♂. Usually, the medio-longitudinal keel of the thoracic nota is contrastive ochre to orange (e. g. lectotype, Fig. 17I) and quite often there is a dark longitudinal line or streak lateral of the keel. Occasionally, the medio-longitudinal streak is continued but mostly just faintly indicated on the basal abdominal terga. The legs range from plain brown to being unevenly flecked with ochre to clay. Quite frequently, the mesosternum has the three mesosternals marked by a black spot and the meso- and metasternum are notably lighter in colour than the dorsal body surface, being mostly ochre, clay or strawcoloured. The largest elements of the body armature are mostly dark brown to back at the base and tipped with ochre to orange.

Almost all elements of cephalic, thoracic and abdominal armature are subject to quite striking variability, which in particular concerns to the antero-lateral crests of the mesonotal triangular area as well as the meso- and metanotal inter-posterior medials, mesopleurals and metapleural supra-coxals. From the specimens at hand for examination, the ♀ from Dingalan (coll. FH, No. 1104-1, Fig. 17E) and Polillo (coll. FH, No. 1104-6, Fig 17D) best match the lectotype ( Fig. 17I) in colour and armature of the head and body.The example A. Dorsal view (captive reared from Callao Cave, Cagayan Province, North Luzon – arrow pointing to the single metapleural that distinguishes T. draconinus from the very similar T. napalaki n. sp.) [FH 1104-10]. B. Dorsal view (captive reared from Callao Cave, Cagayan Province, North Luzon) [FH 1104-9]. C. Dorsolateral view (captive reared from Callao cave, Cagayan Province, North Luzon) [FH 1104-9]. D. Dorsolateral view (Polillo Island) [FH 1104-6]. E. Dorsolateral view (Palanan, Cagayan Valley, Isabella Province, East Luzon) [FH 1104-3]. F. Lateral view (Palanan, Cagayan Valley, Isabella Province, East Luzon) [FH 1104-3]. G. Lateral view (captive reared from Callao Cave, Cagayan Province, North Luzon) [FH 1104-9]. H. Ventral view (captive reared from Callao Cave, Cagayan Province, North Luzon) [FH 1104-9]. I. Lectotype, dorsal view [UMO © Paul D. Brock].

A. Terminalia of ♀ in lateral view. B. Terminalia of ♀ in dorsal view. C. Terminalia of ♀ in dorsal view. D. Terminalia of ♀ in ventral view. E. Closeup of head, pro- and mesonotum of ♀ from Palanan, Cagayan Valley, Isabella Province, East Luzon [ FH 1104-3 ]. F. Closeup of head, pro- and mesonotum of ♀ from Polillo Island [ FH 1104-6 ]. G. Closeup of head, pro- and mesonotum of captive reared ♀ from Callao Cave , Cagayan Province, North Luzon [ FH 1104-9 ]. H. Closeup of pro-, meso- and metasternum of captive reared ♀ from Callao Cave , Cagayan Province, North Luzon [ FH 1104-11 ]. I. Live captive reared ♀ from Callao Cave , Cagayan Province, North Luzon. J. Live captive reared ♂ from Callao Cave , Cagayan Province, North Luzon .

from Palanan in particular is the one that has all the elements of armature most prominent, while these are least developed in the specimens from Cagayan ( Fig. 17 A-B, G). The Polillo ♀ has the inter-posterior mesonotals and metanotals very prominent and bifid ( Fig. 18F) and the mesopleurals and metapleurals supplied with several smaller spines and tubercles around the base, whereas these latter pleural elements are merely simple spines in all of the specimens from Cagayan. While the lectotype shows the same compound mesopleurals and metapleurals, the inter-posteriors of the meso- and metanotum are rather small and simple, paired spines ( Fig. 17I). The inter-posteriors are represented by multi-tuberculate, compound but rather low conical tubercles in the samples from Cagayan ( Fig. 17G) and at the other extreme are protruded into large and prominent, compound spinose swellings in the ♀ from Dingalan ( Fig. 17F). While the Cagayan specimens and lectotype have the posterior mesal of abdominal terga II-IV small and tubercular, it is represented as a prominent and long spine in the ♀ from Palanan and Polillo , that is scarcely shorter than the huge second paired posteriors;moreover, it is also present on tergum V in these two specimens but merely tubercular. The anterolateral crests of the mesonotal triangular show numerous varieties, being basically trifid but with a variable number of much smaller intercalated spikes ( Fig. 18 E-G). The range of variability of the head and body armature is notably smaller in ♂, all of which are at hand lack any additional basal tubercles at the mesopleurals or metapleurals. The ♂ from Leyte in the author’s collection (coll. FH, No. 1104-48) differs slightly from all other Luzonian specimens by having some smaller intercalated teeth between the three major ventral teeth of the metatibiae and the comparatively somewhat more deeply excavated posterior margin of the anal segment .

Westwood (1848: 78) noted body lengths of 57.0 mm for the ♀ lectotype and 38.5 mm for the ♂ paralectotype in the collection of UMO, thus these two specimens being on the smaller side of the size range of draconinus . The full ranges of body lengths of all examined specimens are 55.0- 63.8 mm for ♀ and 38.0- 47.5 mm for ♂. Due to the morphological differences between populations from different localities partly summarized above, some full sets of measurements are here given in tables 1 and 2 below.

Egg ( Fig. 46 K-L)

Large for the genus; capsule ovoid, slightly constricted just below anterior margin with the dorsalsurface distinctly bulgier than ventral surface and the polar-area with a flattening to very shallow indention dorsally; oval in cross-section and notably higher than wide with capsule 1.5x longer than wide. Surface densely but unevenly covered by smallirregularly clustered wart-like protuberances; these missing anteriorly to leave a smooth rim just below the minutely granular anterior margin. Micropylar plate large and about 0.8x as long as capsule; rather narrowly Y-shaped with the median portion large, almost uniform in width and approaching the lower margin of the unarmed rim at anterior margin of capsule; the two posterolateral extensions gradually tapering towards a fairly narrow tip that notably surpassing the axis of the egg if seen laterally. Posterior portion 90° but roundly V-shaped with a fairly distinct bowl-shaped micropylar cup in centre.Outer margin of plate somewhat raised and marked by about three parallel rows of fringe-like excrescences, the interior portion raised and sculptured like capsule and a fairly broad and indented rim in between the outer margin and sculptured inner portion of the plate smooth. Median line indistinct and seen to be a shallowly raised and rather short carina. Operculum almost round in outline and weakly convex; near outer margin with a collar of irregular fringy to peg-like excrescences as well as a broad inner rim of similar but gradually prolonging excrescences; only the centre unarmed. Colour dark brown with all the protuberances of the capsule and micropylar plate ochraceous to pale grey; the operculum rather blackish brown with the fringy excrescences grey. The example from Polillo (coll.FH, No.1104-E2) is slightly more elongate in shape than all other examined eggs and almost black with the sculpturing of the capsule less contrasting in colour and comparatively less developed. Measurements [mm]: Length incl. operculum 4.2, length 4.0, width 2.7, height 3.1, length of micropylar plate 3.3.

Remarks. – This species was originally described upon a ♀ and a ♂ from an unspecified locality in the collection of UMO, of which (Bragg, 1995: 27) designated the ♀ as the lectotype ( Fig. 17I). Westwood (1848, plate 38: 5) only illustrated the ♀ and therefore detailed illustrations, also showing the noteworthy intraspecific variability, of both sexes are presented herein. The egg is here described and figured for the first time ( Fig. 46 K-L).

Matsumura & Hirayama (1932) illustrated an immature ♀ identified as “ Hoploclonia draconina ” from Kotosho Island southeast of Taiwan basedon a unique specimen in the collection of NTUC. The identity of the specimen was doubted by Shiraki (1935: 24) and illustrations of the specimen were provided by Huang (2002) as well as Chen & He (2008). These clearly show the specimen to be misidentified and to represent T. napalaki n. sp. instead. The record is very doubtful, since Tisamenus is an endemic of the Philippines, and thus can be regarded as not natural. However, it is not be entirely ruled out that a specimen was floated to Kotosho Island during a typhoon, usually northing storms that come from the Philippines and hit the south-eastern regions of Taiwan. The Luzon Strait, that separates the Philippines to the South and Taiwan to the north, is merely about 300 kilometres wide and within it lie the Babuyan Islands and Batanes Islands that might act as a land connection. Moreover, T. napalaki n. sp. is distributed in the very northeast of Luzon and on the island of Palaui, although no records are yet known from the Babuyan or Batanes Islands.

A ♂ in the author’s collection (coll. FH, No. 1104-48) from the island of Leyte, one of the Eastern Visayas islands, fully matches with Luzonian specimens of T. draconinus , except for the slight traits mentioned above. However , since all other known records suggest this species to be restricted to northern Luzon , a distribution on Leyte appears fairly doubtful and thus, the locality data might be erroneous .

This species is commonly reared in Europe originating from two very differently coloured ♀ that were collected by Thierry Heitzmann ( Philippines) and Albert Kang ( Singapore) close to Callao Cave, Cagayan Province, North Luzon in November 2015. This sexual culture stock has since been distributed as Tisamenus sp. ‘Cagayan’ and is the perhaps most widespread of all Tisamenus spp. Among European cultures. This is mainly due this species has proven exceedingly productive and fast developing. Although very common and widely spread throughout European breeders no culture number has yet been attributed by the Phasmid Study Group.

Distribution. – “ Philippines ” [UMO – type locality]). N-Luzon: Province Aurora (Sierra Madre, Dingalan, 230 m [FH]); Province Isabela (Sierra Madre, Cagayan Valley, Palanan [FH]; San Pablo [RBINS, TB]; Province Cagayan (Peñablanca Municipilatity, near Callao Cave [FH]); Province Quezon (Polillo Island [FH]); Mountain Province (Apayao, Ripang [ANSP]). Leyte: Province Leyte (Mahaplag [FH]).