Pterinoxylus crassus Kirby HT 1889
Creators: name: Hennemann, Frank H.
name: Conle, Oskar V.
name: Valero, Pablo
name: Nishida, Kenji
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Phasmida
Phasmatidae
Pterinoxylus
Pterinoxylus crassus

description: Pterinoxylus crassus Kirby, 1889
Figs. 4–6, 21B, 22A–B, 23, 24A, 31
Pterinoxylus crassus Kirby, 1889: 502. HT, ♀: La Plume, Dominica, March 1889, 89 23; Pterinoxylus crassus, type; Pterinoxylus crassus Kirby; Pterinoxylus crassus Kirby HT; BMNH(E) #844938 [NHMUK].
Kirby, 1904: 362.
Redtenbacher, 1908: 428.
Moxey, 1972: 155, pl. 15: 25 (♀, HT).
Langlois, Lelong, Rastel, Polidori, & Dorel, 2000: 50, figs. 20a–g (♂, ♀, nymph) & photos 19–22 (egg).
Lelong, Langlois, Rastel, & Dorel, 2003: 26a–g (♂, ♀, nymph) & photos 35–38 (egg).
Lelong & Langlois, 2005: 268, figs. 25–39 (♂, ♀), 43–46 (egg).
Otte & Brock, 2005: 294.
Simoens, 2005: 7. (Rearing)
Langlois, Lelong & Dorel, 2006: 47, figs. 20a–g (♂, ♀, nymph), photo 7 (live ♀) & 30–33 (egg).
Langlos & Lelong, 2010: 67.
Harman, 2013: 13. [Notes on origin of culture stock]
Hennemann, Conle & Perez–Gelabert, 2016: 27, figs. 37–44.
Brock, Marshall, Beccaloni & Harman, 2016: 166. (Type data)
Material examined (35 ♂♂, 36 ♀♀, 3 nymphs, eggs):
DOMINICA:
1 ♀: Domenica, 89–99 [NHMUK].
SAINT LUCIA:
1 ♂: St. Lucia, Mtn. Forest, 12.I.1936, H.E. Box.; Pres. By Com. Inst. Ent. B. M. 1952–302; Diapherodes gigantea (Drury) det. Moxey 1972 [NHMUK]; 1 ♀: Pterinoxylus crassus, Millet Forest Trail, 01.XI.2003, Alt. 230–260 m, Sainte–Lucie, SL03–095; Collection ASPER, Col. E. Dorel, F. Langlois & P. Lelong [MNHN]; 4 ♂♂, 3 ♀♀, 25 eggs: ex Zucht: F. Hennemann, Herkunft: Saint Lucia [coll. FH, No's 0588–25 to 31, E2].
MARTINIQUE:
1 ♀: Montane du Vauclin, 7.XI.1998, réf. MAR 98–017 [MNHN, coll. ASPER]; 1 ♂: Morne Aca, 6.XI.1998, réf. MAR 98–014 [MNHN, coll. ASPER]; 2 ♂♂, 3 ♀♀, 3 ♂♂ (nymphs), 4 ♀♀ (nymphs), eggs: Ex Zucht: F. Hennemann, urspr.: Martinique, 2006–2007 [coll. FH, No's 0588–1 to 11 & E1]; 2 ♂♂, 2 ♀♀: Ex Zucht: R. Krijns (Maastricht) 2008, Herkunft: Martinique (PSG No. 281) [coll. FH, No's 0588–12, 14, 18, 21]; 1 ♂: Ex Zucht: R. Galunder (Nümbrecht) 2008, Herkunft: Martinique, PSG No. 281 [coll. FH, No. 0588–15]; 4 ♂♂, 3 ♀♀: Ex Zucht: I. Morisse 2009, Herkunft: Martinique, Montagne de Vauclin (PSG No. 281) [coll. FH, No's 0588–16, 17, 19, 20, 22–24]; 21 ♂♂, 22 ♀♀: Ex Zucht O. Conle 2004–2005, PSG 281, Martinique: Montagne de Vauclin, leg. ASPER Team 11.1998 [coll. OC, No's 0279–1 to 47].
Diagnosis: Females are similar to the Central American P. perarmatus (Redtenbacher, 1908) with which they share the strongly convex basal portion of the subgenital plate (Fig. 6A). They are however readily distinguished by the more flattened head and lack of the prominent pair of auriform cephalic lobes seen in P. perarmatus as well as having the anal region of the alae irregularly tessellated instead of striped radially. Furthermore, the subgenital plate is shorter and projects beyond the apex of the abdomen by noticeably less than the combined length of abdominal terga VIII–X. Males are most similar to those of P. spinulosus Redtenbacher, 1908 but readily differ by the more convex and more prominently spinose vertex (Fig. 6H), less spinose mesonotum, slender protibiae and lack the characteristic, dentate dorsal apical lobe of the meso- and metatibiae seen in P. spinulosus. The eggs of P. crassus differ from those of all other species in the genus by the very prominently raised ridges of the capsule as well as the open and net-like polar and opercular excrescences (Figs. 22A–B)
Description. The colouration is described mostly from colour photographs of numerous live wild and captive reared specimens.
♀♀ (Figs. 4, 6A–C, 6G, 23A, 23C): Medium sized to large for the genus (body length incl. subgenital plate 131.0– 170.5 mm), form twig –like and moderately stocky with a rather short and broad, basally convex subgenital plate. General colouration different shades of reddish or greyish mid to dark brown with irregular paler speckles and markings. Often with an elongate central whitish marking on mesonotum and a large whitish marking on abdominal tergum V. Sometimes body with several longitudinal dark markings that vaguely indicate dark longitudinal streaks or lines (e.g. ♀ from Saint Lucia in MNHN, Fig. 4B). Head usually with a white marking between the eyes, which has two black spots in its centre. Occasionally with further whitish markings on body and legs. Antennae pale brown, the antennomeres with a blackish dorsal spot at apical margin. Eyes yellowish brown with darker speckles. Tegmina plain mid to dark brown, occasionally with the anterior margin blackish. Costal region of alae reddish mid brown with paler spots and a pale reddish tympanal area sub-basally. Anal region transparent pale brown with irregular dark brown or black markings; the markings darkest along the anal veins.
Head: Oval in cross-section, parallel-sided and about 1.4x longer than wide. Between the eyes with two low transverse humps. Vertex somewhat raised in centre and with two pairs of distinct blunt spines, which are surrounded by various smaller spines or spiniform tubercles (Fig. 6G); a further pair of prominent spines at posterior margin. Vertex and genae otherwise irregularly tuberculose. Eyes of moderate size, circular and convex; their diameter contained 2.2x in length of genae. Antennae reaching about two-thirds along mesothorax, consisting of 25–27 segments. Scapus indistinctly longer than wide, compressed dorsoventrally, deflexed laterally and broadly oval in dorsal aspect. Pedicellus subcylindrical and about half the length of scapus. Third antennomere 1.5x longer and narrower than pedicellus.
Thorax: Pronotum about as long but slightly narrower than head, 1.5x longer than wide, rectangular and gently constricted medially. Median transverse sulcus distinct, gently curved and reaching lateral margins of segment; anterior half with a slightly impressed median line. Surface otherwise irregularly set with small, spine-like tubercles and granules, a ± enlarged and spiniform pair of tubercles near posterior margin and slightly enlarged pair at anterior margin (Fig. 6G). Mesothorax moderately slender and about 4x longer than pronotum; sometimes slightly swollen pre-medially. Mesonotum with a very fine longitudinal median carina and complete surface irregularly rugulose and rather sparsely set with obtuse tubercles of variable sizes; sometimes with a small hump or cluster of spiniform tubercles pre–medially. Meso- and metapleurae and mesosternum irregularly set with longitudinally directed rugulae, some of which are partially raised to form tubercle-like humps. Metasternum sparsely granulose and with a few scattered nodes. Tegmina broadly oval with a small, rounded central hump and reaching about halfway along median segment. Alae variable in length and at best reaching to posterior margin of abdominal tergum II.
Abdomen: Median segment 1.5x longer than metanotum, rectangular, longer than wide and smooth. Complete surface of remaining terga to a variable degree rugulose and aerially granulose; II–IX with a pair of closely placed, irregular longitudinal median carinae. These usually terminating in a small tubercle at posterior margin (often a spiniform projection on VII–IX). A further, irregularly shaped lateral carina present, which in some specimens terminates in a ± distinct spiniform projecting at posterior margin (e.g. ♀ from Saint Lucia in MNHN, Fig. 4B). Segments II, VI and VII roughly equal in length and somewhat shorter than III–V; II–III increasing in width, IV–VII gradually decreasing in width; all longer than wide. Tergum VII with lateral margins moderately deflexed to form an irregularly sub-angular lobe in posterior half; the lobe laterally projecting by less than width of segment (Fig. 6B). Sterna II–VII with a pair of short but notably raised carinae or ridges near posterior margin; otherwise unevenly rugulose. Praeopercular organ formed by a distinct, peg-like median tubercle near posterior margin of sternum VII (Fig. 6C). Terga VIII–X narrower than all previous and roughly uniform in width. VIII about 3/5 the length of VII strongly convex, slightly constricted medially and about 1.3x longer than wide. Anal segment as long as IX, flattened and gently narrowed towards the apex; posterior margin with a small but distinct median indention. Epiproct very small, roughly triangular, transverse and with a distinct dorsal keel (Fig. 6B). Cerci very small, subcylindrical, somewhat tapered towards the tip and just reaching posterior margin of anal segment. Subgenital plate of moderate length for the genus and extending beyond apex of abdomen by more than the length of the anal segment; basal half strongly convex, obtusely keeled and boat-shaped, then angled upwards post-medially and from there on increasingly flattened and scoop-like with the apex rounded to obtusely triangular (Figs. 6A–B).
Legs: All relatively short and stocky; profemora two-thirds the length of mesothorax, mesofemora somewhat more than half the length of mesothorax and hind legs reaching to posterior of abdominal tergum VI. Profemora with anterodorsal carina raised and forming 4–5 large and obtuse tooth–like lobes, the posteroventral carina just weakly expanded, unarmed and merely with a broad, roughly triangular lobe sub-apically (Fig. 6G). Anterodorsal carina of protibiae moderately deflexed and forming four obtusely triangular lobes; the most apical one being largest. Posteroventral carina lamellate and increasing in width until just slightly before the apex, then abruptly narrowing; slightly wavy but unarmed. Posterodorsal carina of mesofemora with a prominent, rounded sub-apical lobe and 2–3 much smaller, occasionally toothed lobules or teeth in basal half; anterodorsal carina smooth except or a prominent, rounded sub-apical lobe. Antero- and posteroventral carinae with an enlarged, triangular tooth-like lobe sub-apically and usually three smaller teeth in basal half. Dorsal carinae of metafemora smooth or with three very indistinct tooth-like swellings in basal half and a prominent, triangular sub-apical lobe on posterodorsal carina. Antero- and posteroventral carinae with 4–9 indistinct, obtuse teeth which increase in size towards the apex of femur and may become almost obsolete towards the base. Medioventral carina of meso– and metafemora indistinct. Ventral carinae of meso- and metatibiae smooth, the anterodorsal carina with a prominent toothed lobe near the apex and a small, rounded sub-basal lobe; the latter less distinct on metatibiae. Probasitarsus almost as long as following two tarsomeres combined; dorsal carina strongly raised and forming a distinct foliaceous lobe; a smaller dorsal lobe present on tarsomeres II and III. Meso- and metabasitarsus slightly longer than following tarsomere and with a small, triangular (sometimes bi-dentate) dorsal lobe.
♂♂ (Figs. 5, 6D–F, 6H, 21B, 24A). Of average size for the genus (body length 94.0– 106.5 mm), form moderately slender and stick-like with well-developed alae (length 43.0–54.0 mm) and rather slender protibiae. General colouration of body different shades of mid to dark or almost blackish brown, sometimes with a slight reddish wash. Head with a pair of small black markings between the eyes. The largest cephalad and thoracic tubercles and spines usually buffy to reddish brown. Tegmina of same colour as body and often with a distinctive white diagonal streak in interior half, which forms a V-shaped white marking when the wings are closed. Costal region of alae with a reddish hue and dull red ventrally. Anal region dark grey with numerous smaller and larger transparent patches; all anal veins dark greyish brown with interruptions at the transparent patches. Antennae dull ochre to mid brown dorsally and black ventrally.
Head: Basically as in ♀♀, central portion of vertex more strongly convex (Fig. 6H) and eyes more prominent and projecting hemispherically from head capsule, their diameter contained only 1.4x in length of genae. Entire cephalad armature much more pronounced, with all tubercles rather spiniform and acutely pointed; the largest cephalad pair occasionally with a bifid apex. Tubercles of genae however much less developed to obsolete. Antennae reaching posterior margin of tegmina and with 29–30 segments; otherwise as in ♀♀ but scapus less prominently dilated.
Thorax: Pronotum as in ♀♀ but tubercles less pronounced; a more prominent pair of spiniform tubercles present near posterior margin (Fig. 6H). Mesothorax elongate, slender, cylindrical and 4.5x longer than pronotum; complete surface very slightly and unevenly rugulose. Mesonotum with a faint longitudinal median carina and set with a variable number of distinct spiniform tubercles of variable sizes (Fig. 6H); these gradually decreasing in size towards posterior of mesonotum. Meso- and metapleurae with a longitudinal row of nodes. Meso- and metasternum set with a variable number of scattered nodes or obtuse tubercles. Tegmina sub-oval on outline, slightly projecting over posterior margin of metanotum and with a fairly flat, gently rounded central hump. Alae reaching about half way along abdominal tergum V.
Abdomen: Median segment 1.2x longer than metanotum, almost 3x longer than wide and smooth. Segment II very slightly longer than median segment, II to VII slightly decreasing in length; II about 3x, VII only 2.6x longer than wide. II–VII parallel-sided and of uniform width. Terga II–IX with a pair of closely placed fine longitudinal median carinae, surface otherwise very weakly rugulose; V–IX with a further more pronounced lateral carina. All sterna rugulose and sparsely granulose; the rugulae roughly forming two irregular longitudinal carinae. Tergum VIII three-quarters the length of VII, strongly convex and very slightly widening towards the posterior. IX three-quarters the length of VIII, almost 2x longer than wide and parallel-sided. Anal segment two-thirds the length of IX, subrectangular in dorsal aspect but slightly narrowed in posterior portion; the posterior margin with a shallow median indention and the outer portions broadly and weakly rounded (Fig. 6E); ventral surface of outer portions of posterior margins armed with a few small denticles. Epiproct very small, transverse and almost fully hidden under anal segment. Cerci small, strongly compressed basally and the apex slightly club-shaped; somewhat projecting beyond posterior margin of anal segment. Vomer broadly triangular in shape, the terminal hook slightly dextrad-directed, acutely pointed and strongly upcurved (Fig. 20B). Poculum strongly convex with a bluntly conical basal hump and slightly projecting over posterior margin of tergum IX (Fig. 6D); the posterior half carinate longitudinally (Fig. 6F) and the posterior margin bi-lobed with a deep median incision (Fig. 21B).
Legs: Relatively longer and slenderer than in ♀♀; profemora almost equal in length to mesothorax, mesofemora three-quarters the length of mesothorax and hind legs reaching to posterior margin of abdominal segment VI. Anterodorsal and posteroventral carina of profemora moderately lamellate, the former gently wavy and usually forming about four tooth-like lobules, the latter with a variable number of small teeth (Fig. 6H). Anterodorsal carina of protibiae slightly deflexed and irregularly undulate, the posteroventral carina somewhat more distinctly lamellate with the margin sometimes forming an indistinct, rounded lobe sub-apically. Armature of mid and hind legs generally as in ♀♀ but much less pronounced. Probasitarsus as long as following two tarsomeres combined and with a distinct roundly triangular dorsal lobe; second tarsomere with a much smaller dorsal lobe (Fig. 6H). Meso- and metabasitarsus almost as long as following two tarsomeres combined, dorsal carina slightly raised and rounded.
Nymphs (Fig. 23B): Newly hatched nymphs have a body length of about 30.0 mm and are ochraceous mid brown with the frons greyish and a distinctive pale grey transverse sub–basal band on the meso– and metatibiae. The sex can be determined from 2 nd instar onwards. Later instars have the leg armature much more strongly developed than the adult insects with the legs in general being much stockier in relation to the body. Female nymphs often exhibit attractive white markings on the mesonotum, median segment and abdominal tergum V (Fig. 22B), whilst a pale marking is only present on abdominal tergum V in ♂♂.
Variability: Both sexes show notable variability in colouration, size as well as the head and thoracic armature. Whilst some degree of variability is seen within the individual island populations, some variations appear to be peculiar to each of these populations. P. crassus has so far been recorded from the islands of Dominica, Martinique and Saint Lucia. Specimens from Dominica and Saint Lucia are considerably larger than specimens from Martinique (♀♀ 151.0– 170.5 mm compared to 131.0–144.0 mm; see table 2 below) and are slightly stockier in shape. The Dominican specimens differ from the other two populations by having the alae slightly longer with the anal region more conspicuously tessellated with hyaline markings. The population from Martinique has the cephalic armature more pronounced than specimens from either Dominica or Saint Lucia. Whilst ♂♂ from Martinique mostly have a distinctive white diagonal stripe on the inner portion of the tegmina, this is very rarely seen in specimens from Saint Lucia. Unfortunately, no ♂♂ are so far known from the type-locality Dominica.
Eggs (Figs. 22A–B): Very large, alveolar, capsule slightly more than 3x longer than wide, almost cylindrical in cross-section. Surface of capsule minutely granulose, distinctly pitted and with several irregular, longitudinal raised ridges. Polar-area with a hollow, crest- and net-like excrescence; the outer margin irregularly crenate. Micropylar plate small, covering less than one-quarter of capsule, oval and gently tapered towards anterior end. Medially with two longitudinal, parallel ridges and a central, longitudinal impression in between. Micropylar cup distinct, cup-like and at posterior margin of plate; dark brown. Outer margin faint and darker brown than capsule. Median line protruded as a distinct longitudinal keel which almost reaches the posterior end of capsule. Operculum almost circular, with a high and slender central spine and outer margin with a prominent, hollow crest-like excrescence which has the anterior margin irregularly crenate; anterior two-thirds open and of net–like structure. Height of operculum about two-fifths the length of capsule. General colouration plain dull beige to dark brown, micropylar plate slightly darker. Measurements [mm]: Overall length 9.3–9.6, capsule length 7.8–8.2, width 2.6–2.8, height 2.8–3.0, length of micropylar plate 1.7–1.8, height of operculum 1.9–2.0.
Comments: Kirby (1889: 502) originally described Pterinoxylus crassus based on a single ♀ from Dominica in the collection of NHMUK (Fig. 4A). In addition to the holotype there is another ♀ from Dominica in the NHMUK collection, which appears to have been collected along with the holotype possibly from same locality. Like the holotype it seems to have been provisionally preserved in spirits. It is slightly shorter, bears the same data label and is mounted on the same kind of pin. Certainly, this second ♀ was overlooked by Kirby when he described P. crassus.
P. crassus is successfully cultured in Europe from stocks originating from Martinique and imported in 1998 as well as from Saint Lucia imported in 2003. The insects develop well in moderately humid conditions with good ventilation and plenty of fresh food. In captivity the following alternative food plants are accepted to a variable degree: oak (Quercus robur & Q. petraea, Fagaceae), bramble (Rubus fruticosus, Rosaceae), raspberry (Rubus idaeus, Rosaceae), hypericum (Hypericum patulum & H. calycinum, Hypericaceae), eucalyptus (Eucalyptus gunnii, Myrtaceae) and guava (Psidium guajava, Myrtaceae). In the wild Langlois, Lelong, Rastel, Polidori, & Dorel, (2000: 51), Lelong, Langlois, Rastel & Dorel (2003: 75) and Lelong & Langlois (2005: 47) reported P. crassus feeding on guava, Coccoloba sp. (Polygonaceae) and Hibiscus elatus (Malvaceae). Hatching rates of the eggs are high (80–95 %) and the mortality of the newly hatched nymphs very low. The duration of incubation for the eggs is between 6–9 months and nymphs grow fairly slow, taking 5–6 months to reach maturity.
Distribution (Fig. 31): Lesser Antilles. Dominica (La Plume). Martinique (Montane de Vauclin & Morne Aca). Saint Lucia (Mountain forest; Edmond Forest Reserve 472–579 m; Forestiere 183–305 m; Millet Forest Trail 229–259 m).
description: Published as part of Hennemann, Frank H., Conle, Oskar V., Valero, Pablo & Nishida, Kenji, 2022, Studies on Neotropical Phasmatodea XXV: Revision of Pterinoxylus Serville, 1838, with the descriptions of two new species from Costa Rica. (Phasmatodea: Oriophasmata: Cladomorphinae: Pterinoxylini), pp. 1-72 in Zootaxa 5208 (1) on pages 15-22, DOI: 10.11646/zootaxa.5208.1.1, http://zenodo.org/record/7318962