Strigamia Gray, 1843

Bonato, Lucio, Dányi, László, Socci, Antonio Augusto & Minelli, Alessandro, 2012, Species diversity of Strigamia Gray, 1843 (Chilopoda: Linotaeniidae): a preliminary synthesis, Zootaxa 3593, pp. 1-39 : 3-7

Strigamia Gray, 1843

Diagnosis. Geophilomorphs with body distinctly narrowing towards both the anterior and the posterior end ( Fig. 1 ). Head about as long as wide ( Fig. 2 ). Antenna about uniform in width or slightly tapering ( Fig. 3 ); club-like sensilla (sensilla basiconica) only on the terminal article; apical sensilla (sensilla brachyconica) without projections. Clypeus uniformly areolate, without clypeal areas ( Fig. 2 ). Labrum without anterior alae and without obviously distinct lateral parts; margin concave, lined with short denticles. Epipharynx with bilobate border between clypeal and labral parts. Mandible with a single pectinate lamella. First maxillae with distinct, entire coxosternite and bi-articulate telopodites, without elongate lappets ( Fig. 2 ). Second maxillary coxosternite uniformly sclerotized, the anterior margin concave, without inner processes; telopodite composed of three articles, bearing a subconic bent claw ( Fig. 2 ). Forcipular metatergite subtrapezoid, posteriorly as wide as the subsequent tergite, the lateral margins converging anteriorly. Forcipular coxosternite wider than long, without anterior denticles; coxopleural sutures complete, entirely ventral, sinuous and distinctly diverging anteriorly; chitin-lines indistinct ( Fig. 4 ). Forcipule relatively short, the trochanteroprefemur without denticles, two distinct intermediate articles, the tarsungulum with one large basal denticle ( Fig. 4 ). Leg-bearing segments without paratergites and without carpophagus pits; metasternites with two paired subovoid posterior pore-fields, usually also two smaller paired anterior pore-fields. Leg claws bearing two slender accessory spines. Ultimate leg-bearing segment with subtrapezoid metasternite; coxal pores present, on the ventral side only ( Figs 5–6 ). Telopodites of the ultimate pair approximately as long as those of the penultimate pair, composed of six articles, swollen in male in comparison with the female, bearing a claw ( Figs 7–8 ). Bi-articulated gonopods in the male, short bilobate gonopodal lamina in the female; a pair of anal pores.

Type species: Strigamia fulva Sager, 1856 , by subsequent monotypy (I.C.Z.N. 1999: art. 69.3).

Synonyms: Linotaenia C.L. Koch ; Scolioplanes Bergsøe & Meinert, 1866 ; Tomotaenia Cook, 1895; Diplochora Attems, 1903 ; Paraplanes Verhoeff, 1933 ; Leptodampius Chamberlin, 1938 (new synonymy); Korynia Chamberlin, 1941 (new synonymy).

Notes on synonymies. All nominal genera listed above are either confirmed or recognized for the first time as synonyms of Strigamia because their type species match the diagnosis of Strigamia given above. For the species that are known only from the literature, this evaluation was obviously limited to the characters described or illustrated; however, we found no evidence of major differences that justify recognizing these species in distinct genera. In the following, the history of taxonomic opinions is summarized, and arguments for the new synonymies are discussed.

The name Strigamia was first introduced by Jones (1843), who acknowledged J.E. Gray as its author. The name was explicitly adopted for the genus that had been previously called Geophilus Leach , but without providing reasons for the substitution. When introduced, Strigamia was accompanied by a very vague diagnosis that fits the concept of the entire Geophilomorpha , and no species were included in it. The concept of Strigamia and the identity of its type species remained unclear for about a century, with different students elaborating different opinions. Some authors considered Strigamia merely a junior synonym of Geophilus ( Gervais 1847; Newport 1856; Latzel 1880; Cook 1895). Instead, Wood (1862, 1865, 1867) adopted Strigamia as a valid genus name, with a concept much broader than the current one. Conversely, other influential authors introduced and adopted different generic names for species that are now in Strigamia ( C.L. Koch 1847; Bergsøe & Meinert 1866; Cook 1895; Attems 1903, 1929). Such nomenclatural and taxonomic uncertainties were debated between Crabill (1953, 1954a, 1954b, 1962a) and Chamberlin (1954, 1963). The confusion surrounding the type species of Strigamia was eventually clarified by Crabill (1953), who pointed to the fact that S. fulva was the first species included in the genus. Only after that, Strigamia began to be adopted broadly, in a concept broadly corresponding to the one here defined.

Linotaenia was introduced by C.L. Koch (1847) to include four species, namely Geophilus crassipes C.L. Koch (currently Strigamia crassipes ), Geophilus subtilis C.L. Koch and Linotaenia rosulans C.L. Koch (both currently regarded as junior synonyms of Geophilus acuminatus Leach , currently Strigamia acuminata ), and Geophilus nemorensis C.L. Koch (currently Schendyla nemorensis , in the Schendylidae ), but without selecting a type species. Because of the heterogeneous original circumscription of Linotaenia, Meinert (1870) and other authors considered it as corresponding partly to Scolioplanes (currently regarded as a synonym of Strigamia ) and partly to Schendyla Bergsøe & Meinert. L. rosulans was selected validly as the type species by Pocock (1890), whereas other designations are invalid either because they are subsequent or because the selected species was not originally included in the genus. Linotaenia was adopted with a concept approximately corresponding to our concept of Strigamia , by some of the most active American authors (including C.H. Bollman and R.V. Chamberlin), whereas most European authors rejected it for Scolioplanes . Linotaenia was also adopted by Crabill (1953) as a subgenus of Strigamia but later synonymized under Strigamia by Crabill himself (1960a). The latter opinion was followed by most subsequent authors.

Scolioplanes was introduced by Bergsøe & Meinert (1866) to include three species, namely Geophilus acuminatus Leach , Geophilus crassipes C.L. Koch and Geophilus maritimus Leach (all currently under Strigamia ), without selecting a type species. G. maritimus was selected validly as the type species by Cook (1895). Scolioplanes was used as a valid genus, with a concept approximately corresponding to our concept of Strigamia , by most European and Japanese authors (including C. Attems, H.W. Brölemann, F. Meinert, A. Seliwanoff, Y. Takakuwa, and K.W. Verhoeff), while other students regarded Scolioplanes as a junior synonym of Linotaenia ( Pocock 1890; Bollman 1893a, 1893b; Cook 1895; Silvestri 1905; Crabill 1953; Chamberlin 1954). Scolioplanes was first synonymized under Strigamia by Crabill (1960a), followed by most subsequent authors.

Tomotaenia was introduced by Cook (1895) by designating Strigamia parviceps Wood as type species and including tentatively another twelve species, namely S. bidens Wood , S. bothriopus Wood , S. chionophila Wood , S. fulva Sager , S. laevipes Wood , S. maculaticeps Wood , S. walkeri Wood , Linotaenia branneri Bollman and Scolioplanes exul Meinert (both currently included in Strigamia ), Scolioplanes robustus Meinert and Scolioplanes ruber Bollman (both synonymized under Strigamia species), and Scolioplanes longicornis Meinert (of uncertain identity). Tomotaenia was used as valid only by a few other authors ( Crabill 1954a; Kevan & Scudder 1989; Bonato et al. 2011), but it was rejected or at least ignored by most other authors. It was listed explicitly among the synonyms of Scolioplanes by Attems (1929) and among those of Strigamia by Matic (1972). As it is dubious if the type species S. parviceps actually belongs to the genus Strigamia as diagnosed here (see below under “Uncertain species”), the synonymy of Tomotaenia under Strigamia is followed here only provisionally.

Diplochora was introduced by Attems (1903) for the single species D. fusata Attems , which is the type species by monotypy. No other species were assigned to Diplochora , which was merely cited by other authors. Diplochora was synonymized under Tomotaenia by Crabill (1962a, 1962b), followed by Chamberlin (1963), who also synonymized the type species of the two genera. Diplochora was first regarded as a synonym of Strigamia by Mercurio (2010).

Paraplanes was introduced by Verhoeff (1933) for the single species P. svenhedini Verhoeff , which is thus the type species by monotypy. Verhoeff (1938a) subsequently included another species, P. californicus Ve rh o eff (currently a synonym of Strigamia fusata ). Paraplanes was synonymized under Tomotaenia by Chamberlin (1941), but it has been cited as valid also later ( Shinohara 1981a; Wang & Mauriès 1996). It was first listed among the synonyms of Strigamia by Mercurio (2010).

Leptodampius was introduced by Chamberlin (1938) for the single species L. lamprus Chamberlin , which is the type species by original designation. The validity of the genus was never questioned. As to its taxonomic position, Chamberlin (1938) did not assign it explicitly to any family but described it as a “geophiloid”, Crabill (1962b) recognized it as belonging to Dignathodontidae under a concept including also Linotaeniidae , but recent catalogues listed it as a member of the family Geophilidae ( Kevan 1983; Mercurio 2010). Leptodampius is recognized here as a synonym of Strigamia because the original description of L. lamprus matches Strigamia in major diagnostic features such as the elongation of the head and the forcipules, the shape of the forcipular tarsungula, the absence of chitin-lines, and the size of the ultimate legs; additionally, Chamberlin (1938) acknowledged that Leptodampius is similar to Agathothus Bollman (which is close to Strigamia ; see below under “Similar genera”) and differs from it mainly for a large basal denticle on the forcipular tarsungulum and the narrower metasternite of the ultimate leg-bearing segment, two characters that are found in Strigamia but not in Agathothus .

Korynia was introduced by Chamberlin (1941) to include three species, namely K. carmela Chamberlin , K. texensis Chamberlin and K. tripora Chamberlin , among which K. carmela was designated originally as the type species. Another species, K. auxa Chamberlin , was later described under the genus ( Chamberlin 1954). Crabill (1954a) treated Korynia as a subgenus of Tomotaenia, and assigned to it also D. fusata and his new species T. (K.)

urania Crabill. However , Crabill’s classification was not followed by other authors, and Korynia was often ignored although not rejected formally ( Mercurio 2010). Korynia is recognized here as a synonym of Strigamia because, based on the accounts by Chamberlin (1941, 1954), it matches Strigamia in major diagnostic features such as the shape of the head, the forcipules and the ultimate legs in the male. However, the ventral pore-fields were not mentioned by Chamberlin (1941), while they were described as “not detected” by Chamberlin (1954) in K. texensis , but we agree with Crabill (1954a) that this should not be construed as a reliable indication by Chamberlin that the pores are actually absent in the Korynia species. Actually, Crabill (1954a) found that, in another species recognized by him as representative of Korynia , the pores are present, at least in the anterior part of trunk, although detectable with difficulty. Supporting our opinion is also the fact that Chamberlin acknowledged explicitly that Korynia resembles Linotaenia specifically in the head shape, the labrum, the mouth parts, and the basal denticle of the forcipular tarsungulum ( Chamberlin 1941), and that it resembles Tomotaenia specifically in the pattern of coxal pores ( Chamberlin 1954).

Similar genera. Strigamia is most similar to the genera Agathothus Bollman, 1893 , Araucania Chamberlin, 1955 , Damothus Chamberlin, 1960 , and Zantaenia Chamberlin, 1960 . These are all small genera, including one or two species each. To the exclusion of Araucania , which is endemic to a small region in the central-southern Andes, all others inhabit North America within the range of Strigamia . With the exception of Damothus , the morphology of these genera is not known at a satisfactory level, and they have been recorded very rarely. As far as known, most of them differ from Strigamia in the basal denticle of the forcipular tarsungulum, which is completely wanting in Agathothus and Zantaenia , and double in Damothus . Additionally, the labrum is lined with many projections besides the medial tubercles in Araucania , the legs of the ultimate pair are distinctly longer than the penultimate pair at least in Agathothus and Damothus , the ventral glandular pores are putatively lacking in Damothus , and the ultimate legs of the male lack claws in Zantaenia .

Other genera have been considered in the past as closely related to Strigamia or even as its synonyms, and thus often classified in the same family Linotaeniidae . This is the case of Horonia Chamberlin, 1966 , Javaenia Chamberlin, 1944 , Malochora Chamberlin, 1941 and Pagotaenia Chamberlin, 1915 . However, based on their original descriptions, they are most probably much more distant from Strigamia , if not misplaced at all.

Included species. The species we recognize in Strigamia are listed below in alphabetic order. Main morphological features are given in Table 1 . An asterisk (*) indicates the species whose taxonomic validity is tentative only. Original combinations, type localities and information about type specimens are given in Appendix 2.

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Figures

FIGURE 1. A female Strigamia crassipes at rest on the soil (Dolomiti Bellunesi, Italy; photo by L. Bonato).

FIGURES 2 – 4. Morphology of adult Strigamia. (2) Head, ventral view, of a female S. platydentata from Tokashiki island, Japan. (3) Right antenna, dorsal view, of a male S. acuminata from Passo San Boldo, Italy. (4) Forcipular segment, ventral view, of a male S. crassipes from Dolomiti, Italy. Full data of specimens in Appendix 1.

FIGURES 5 – 6. Morphology of adult Strigamia. (5) Ultimate pleuropretergite, dorsal view, of a male S. acuminata from Malabotta, Italy. (6) Ultimate leg-bearing segment without telopodites, ventral view, of a male S. bicolor from Taroko, Taiwan. Full data of specimens in Appendix 1.

FIGURES 7 – 8. Morphology of adult Strigamia. (7) Ultimate leg-bearing segment and postpedal segment, ventral view, of a female S. bothriopus from near Gatlinburg, Tennessee. (8) Ultimate leg-bearing segment and postpedal segment, ventral view, of a male S. crassipes from Dolomiti, Italy. Full data of specimens in Appendix 1.

Tables

TABLE 1. Main characters of the species of Strigamia recognized here as valid. An asterisk (*) indicates species whose taxonomic distinction is tentative only. The number of specimens upon which body length and number of legs have been evaluated (n) is given in three classes (1 – 2 specimens, 3 – 10 specimens, more than 10 specimens), because sometimes the number is known only approximately.

species	n	direct obs.	max. length [mm]	Ƥ leg pairs	3 leg pairs	ultimate pleuropretergite entire	ultimate metaster nite	coxal pores	distribution
S. acuminata	>10	x	40	39–43	37–41	yes	narrow	scattered	W Palaearctic
S. alokosternum	3–10	x	40	59–67	51–61	no	broad	scattered	E Palaearctic
S. auxa *	1–2	–	38	?	73	no	broad	all close to metasternite	Nearctic
S. bicolor	3–10	x	35	45–53	41–49	no	narrow	scattered	E Palaearctic
S. bidens	>10	x	64	67–81	65–77	yes	narrow	scattered	Nearctic
S. bothriopus	>10	x	60	47–53	43–51	yes	narrow	scattered	Nearctic
S. branneri *	>10	x	37	41–43	39–41	no	narrow	scattered	Nearctic
S. carmela	1–2	–	16	?	53	no	broad	all close to metasternite	Nearctic
S. caucasia	1–2	–	28	?	47	no	narrow	scattered	W Palaearctic
S. chionophila	>10	x	25	37–47	35–45	no	narrow	scattered	Nearctic
S. cottiana	3–10	x	42	59–65	61–65	yes	narrow	scattered	W Palaearctic