Euscorpius latinus, Tropea & Parmakelis, 2022

Tropea, Gioele & Parmakelis, Aristeidis, 2022, Reconsideration of some populations of Euscorpius concinnus complex (Scorpiones, Euscorpiidae), ZooKeys 1100, pp. 117-164 : 117

Euscorpius latinus sp. nov.

Figs 6 , 7 , 8 , 9 , 10 , 11 , 12

Type material.

Holotype: ♂, Italy, Latium, Lepini Mts, near Montelanico (RM), 470 m a.s.l., 41.631314°N, 13.026798°E, 20 June 2013, leg. G. Tropea (GTC).

Paratypes: Italy: Latium: Lepini Mts, near Montelanico (RM), 470 m a.s.l., 41.631314°N, 13.026798°E, 20 June 2013, leg. G. Tropea, 2 ♂♂, 4 ♀♀ (GTC paratypes); same data but 444 m a.s.l., 41.63219°N, 13.02634°E, 1 ♂, 5 ♀♀ (GTC paratypes); same data but 456-467 m, 41.63118°N, 13.02580°E, 41.63092°N, 13.02530°E, 41.63156°N, 13.02547°E, 12 August 2020, leg G. Tropea, 4 ♂♂, 3 ♀♀ (GTC paratypes); Castel Fusano, Rome, 8 April 2012, leg. G. Tropea, 6 ♂♂, 7 ♀♀ (GTC paratypes); Castel Fusano, Rome, ~ 9 m a.s.l., around to 41,73064°N, 12,31516°E, 22 June 2014, leg. G. Tropea, 3 ♂♂, 4 ♀♀ (GTC paratypes); Near Sabaudia (LT), 18 August 2009, leg. G. Tropea, 3 ♂♂ (GTC paratypes); same data but 5 May 2012, leg. G. Tropea, 3 ♀♀ (GTC paratypes); surroundings of Anticoli Corrado (RM), under stones, 42.012665°N, 12.970851°E, May 2014, leg. A. Massimiani, 2 ♀♀ (GTC paratypes); Near Monterotondo (RM), 109 m a.s.l., 42.06871°N, 12.64305°E, 18 April 2014, leg. G. Tropea, 2 ♂♂, 1 ♀ (GTC paratypes); Simbruini Mts., near Trevi nel Lazio (FR), 1 August 1976, leg. R. Argano, 1 ♂, 1 ♀ (GTC paratypes). Molise: Near SP Carovillense, Villa San Michele (IS), 41.74463°N, 14.23146°E, 14 July 2012, leg. G. Tropea, S. Tropea, 5 ♂♂, 1 ♀ (GTC paratypes).

Other examined specimens

(not included in type series). Italy: Latium: Mt. Gennaro, Lucretili Mts., (RM), ~ 1000 m a.s.l., 24 August 2009, G. Tropea, 2 ♂♂, 2 ♀♀ (GTC).

Etymology.

The specific epithet means Latin, due to its range which includes the first area in which the Latins and the Latin language spread, namely the Latium vetus.

Known geographic range.

Italy: Latium (left of the Tiber River; Fig. 32 ).

Diagnosis.

A medium-small, Euscorpius species, total length 25-34 mm. Colour of adults mostly dark brown with darker marbling on most of the body, including chelicerae, but with rare blackish or medium brown specimens. The number of trichobothria on the pedipalp manus ventral surface is four (V 1-3 + Et 1). Trichobothria est and dsb on fixed finger are respectively located distally and proximally to the notch of the fixed finger. The number of trichobothria on the pedipalp patella ventral surface is usually eight and seven (seven in 39.68% of the pedipalps examined). The number of trichobothria on pedipalp patella external surface is usually: eb = 4, eba = 4, esb = 2, em = 4, est = 4, et = 6 (5-7). Trichobothrium i of the femur is slightly proximal to or at the same level of d. The pectinal teeth number in males usually is eight (7-9) and in females usually is seven (6-8). Dorsal spur well developed. Femur is slightly shorter than the patella. Carapace tends to be shorter than long. Carinae V1 follows an external direction to the trichobothria Et1, without forming a Y-shape. Spinules on legs ending with a Y-shape. Ventrolateral and ventromedian carina on metasomal segment V well formed by small, spaced and slightly serrulated granules.

Trichobothrial and pectinal teeth count variation.

The variation observed in 63 examined specimens (29 ♂♂ and 34 ♀♀) is given below (left/right asymmetry not specified).

Pectinal teeth in males (n = 58): 7/7 (1), 7/8 (2); 8/8 (20), 8/9 (2), 9/9 (4); in total, 7 in 6.90% (4), 8 in 77.59% (45), and 9 in 17.24% (10); mean = 8.10, SD = 0.48.

Pectinal teeth in females (n = 67): 5/6 (1), 6/6 (2), 6/7 (7),?/7 (1), 7/7 (15), 7/8 (6), 8/8 (2); in total, 6 in 17.91% (12), 7 in 65.67% (44), and 8 in 14.92% (10); mean = 6.94, SD = 0.62.

Pedipalp patella trichobothria Pv (n = 126): 7/7 (15), 7/8 (20), 8/8 (28); in total, 7 in 39.68% (50), and 8 in 60.32% (76); mean = 7.60, SD = 0.49.

Pedipalp patella trichobothria Pe (n = 81): et = 5/4 (1), 5/5 (3), 5/6 (5), 6/1 (1), 6/6 (29), 4/7 (1); in total, 4 in 2.46% (2), 5 in 17.28% (14), 6 in 79.01% (64), and 7 in 1.23% (1); mean = 5.79, SD = 0.49;

est = 4/3 (1), 4/4 (38), 4/5 (2); em = 3/4 (7), 4/4 (33), 4/5 (1); esb = 2/2 (41); eba = 4/4 (41); eb = 4/4 (39), 4/5 (2).

Description of the male holotype.

Colouration. A general dark brown base colour with more or less marked lighter marbling or reticulation, reddish brown, in the less granulated areas, especially of the metasoma, legs, pedipalps and chelicerae; telson mostly dark brown with two ventrally longitudinal pale brown stripes and one for each side, with reddish brown distal part of the sting; pale brown chelicerae with dark brown reticulation; chelae with fingers ranging from pale yellowish brown to dark reddish brown with dark blackish brown reticulation; legs with most ivory tarsus, the basitarsus and tibia are mostly pale brown, but with dark blackish brown marbling externally, almost pale brown internally, the patella and femur are mostly dark with paler spot externally, and mostly pale brown with dark reticulation internally; pectines and genital operculum whitish ivory; sternites are mostly very pale brownish but the most distal is laterally dark blackish brown with the central part pale brown.

Carapace. Almost completely covered by dense fine granules, especially on the dark marbling. The granules in the lateral anterior part are larger; anterior edge is straight with some granules; deep posterior lateral furrows; two pairs of lateral eyes, and a pair of median eyes; length from centre of median eyes to anterior margin is 40.48% of carapace length.

Mesosoma. The tergites are densely covered with a fine granulation; sternites glossy and finely punctuated; small spiracles inclined to ~ 40° downward towards outside.

Metasoma. Dorsal carinae on segments I-IV with spaced granules; ventrolateral carinae on segment I absent, on segment II and III smooth or obsolete, on segments IV, little marked with some small and spaced granule, with small slightly serrulated granules on segment V; ventromedian carinae absent on segment I-III, little marked smooth or obsolete on segment IV, on segment V it consists of small, slightly serrulated granules, which expands like a fan in the most distal part; dorsal and lateral intercarinal surfaces on segments I-IV are mostly finely granulated, especially on dark marbling, while the ventral surfaces are mostly smooth, the V segment is mostly finely granulated.

Telson. Vesicle with a few small granules, with ventral setae of different size, especially near the vesicle/aculeus juncture.

Pectines. Teeth number 8/8; middle lamellae number 5-5; several microsetae on proximal area of teeth, marginal lamellae, and middle lamellae.

Genital operculum. The genital operculum is formed by two longitudinally devised subtriangular sclerites with genital papillae protruding.

Sternum. Pentagonal shape, type 2; slightly wider than long, with a deep posterior emargination.

Pedipalps. Coxa and trochanter with tuberculated carinae. Femur: dorsal internal and external and ventral internal carinae tuberculated; irregular ventral external carinae formed by tubercles just on 1/3 or 1/4 of femur length; external median carinae formed by lightly serrulated tubercles; anterior median carinae formed by some spaced conical tubercles; intercarinal spaces granulated. Patella: dorsal and ventral internal carinae tuberculated; ventral external carinae crenulated; dorsal external carinae slightly crenulated to rough; intercarinal surfaces finely granulated, especially on the dark reticulations near the internal carinae. Dorsal patellar spur well developed. Chela: chelal carina D1 is distinct, strong, dark and smooth with a few tubercles; D4 is rounded with a few spaced granules; V1 is distinct, strong, dark, from rough to smooth, following an external direction to the trichobothria Et1; V3 is rounded with scattered granules; external carina granulated; intercarinal tegument granulated; the fixed and movable fingers with medium notch and lobe, respectively.

Finger dentition. In the most distal part is present a DD on the tip; MD is formed by very small denticles closely spaced forming an approximately straight line, discontinued at level of the OD; fixed finger has 5/5 OD and 11/10 ID; movable finger has 7/7 OD and 13/15 ID.

Trichobothria. Chela: trichobothria on the pedipalp manus ventral surface V = 2*/3 (V1-3) (*the trichobothrium V3 of the left chela is vestigial) + Et 1 = 1/1; trichobothrium V4 situated on the external surface of the chela, near the carina V1; trichobothrium ratio of et-est/est-dsb is ~ 0.95 and 0.87. Trichobothrium est is distal to the centre of the notch of the fixed finger and dsb is proximal. Patella: Pv = 8/7; et = 6/6, est = 4/4, em = 4/4, esb = 2/2, eba = 4/4, eb = 4/4. Femur: trichobothrium d is slightly proximal to i, while trichobothrium e is well distal to both d and i, and situated on dorsal surface on dorsal external carina.

Legs. Two pedal spurs present; no tarsal spur; ventral row of tarsus with a total of 12/10 spinules on leg III, of increasing size from proximal to distal, ending with two spinules to form a Y-shape; three main flanking tarsal setae present. Tubercles present on ventral and dorsal surface of all leg femora.

Chelicerae. Typical of the genus Euscorpius .

Description of the hemispermatophore.

Type A. It has a well-developed lamina tapered distally; well-developed basal constriction present; truncal flexure present; median projection with lde, ldi, and lb; internal projection distally with 9-11 tines in its crown. The number and the shape of tines of the crown varied between specimens and between the right and the left hemispermatophores.

Comments.

Euscorpius latinus sp. nov. is the southernmost species of the E. concinnus group. The geographically closest species of the E. concinnus group is E. trejaensis sp. nov., which seems to be divided from Euscorpius latinus sp. nov. by the Tiber River. However, in terms of both phylogeny and of DNA sequence divergences, these two species do not seem to be more closely related compared to the others. In fact, according to the concatenated phylogenetic tree 16S rDNA + COI presented herein (Fig. 31 ), E. latinus sp. nov. is placed between E. concinnus , which is more basal to it, and the other species, which are apical to it. Regarding the sequence divergence in 16S marker, between E. latinus sp. nov. and E. trejaensis sp. nov., it ranges from 2.7% to 3.1%, as with E. niciensis stat. nov., from 3% to 2.7% with E. concinnus and from 3.8% to 4.2% with E. stefaniae sp. nov. Morphologically, like the other species of the E. concinnus group and the many cryptic species complex that have been described in recent years, E. latinus sp. nov. is difficult to identify without reference to the locality of origin or with a limited number of specimens. As for the trichobothrial and pectines teeth values, E. latinus sp. nov., together with E. trejaensis sp. nov., has the lowest average of Pv, which is 7.60 and 7.62, respectively, having the highest percentage of Pv = 7, i.e., 39.68%, vs. percentages ranging from 2.78% to 13.33% in E. concinnus , E. niciensis stat. nov. and E. stefaniae sp. nov. and a very similar percentage in E. trejaensis sp. nov., 34.07. While the percentage of Pv = 8 is very similar to both E. concinnus and E. trejaensis sp. nov. (from 60.32%-65.25%), it is very different from that of E. niciensis stat. nov. and E. stefaniae sp. nov. (25% and 81.67, respectively). Dp in males is also quite similar to E. concinnus and E. trejaensis sp. nov. and very different from E. niciensis stat. nov. and E. stefaniae sp. nov. As for Pe-et, E. latinus sp. nov. has the largest percentage of et = 5, i.e., 17.28%, vs. percentages ranging from 5.93% to 10.69%.

Euscorpius latinus sp. nov. is the southernmost species of the E. concinnus group and its known distribution includes central southern Lazio, on the left bank of the Tiber River, and north-western Molise. Regarding the latter location, this is the first time that a member of the E. concinnus group is reported from this region. This could be due to an accidental introduction, but we cannot dismiss the possibility of this area belonging to the natural distributional range of the species. The Apennines in this area are less elevated and more fragmented, and this may have facilitated the colonisation of that region. It remains to be seen if this species continues its distribution to the left of the Tiber River until it reaches Umbria, or if the latter region is inhabited by another species of the E Euscorpius concinnus group, as well as whether the species is also present in Campania.

Euscorpius latinus sp. nov. was found from almost the sea level (e.g., in Castel Fusano, near Ostia (RM)), up to ~ 900 m a.s.l. on the Lucretili Mountains. It was always found in woodlands, mostly mesophilic, but also hygrophilous. It is evident that the species prefers very humid habitats and microhabitats. In these environments, E. latinus sp. nov. behaves as a lapidicolous and corticolous species, since it mainly occurs under stones, but also under branches, trunks, and bark, often rotting, as well as inside pine cones. Euscorpius latinus sp. nov. has not been found in sympatry with other species of scorpions, but it cannot be excluded that rare encounters may occur with T. flavicaudis or Euscorpius italicus (Herbst, 1800) which prefer more rural and less humid habitats than completely natural and very humid ones as E. latinus sp. nov.

Figures

Figure 6. Dorsal and ventral views of Euscorpius latinus sp. nov. male holotype. Scale bar: 4.20 mm.

Figure 7. Dorsal and ventral view of Euscorpius latinus sp. nov. female paratype. Scale bar: 4.20 mm.

Figure 8. Euscorpius latinus sp. nov. male holotype except C and N, that are of a female paratype A carapace B external view of chela of adult male C external view of chela of adult female D ventral view of pedipalp patella E dorsal view of pedipalp patella F external view of pedipalp patella G ventral view of chela H dorsal view of chela I ventral view of metasomal segment V J lateral view of metasomal segment V K telson of adult male L telson of adult female.

Figure 9. Pregnant Euscorpius latinus sp. nov. found under the bark of a trunk.

Figure 10. Euscorpius latinus sp. nov. photographed in its habitat with first instar litter on its back.

Figure 11. Example of the habitat of Euscorpius latinus sp. nov.

Figure 12. Pregnant specimen of Euscorpius latinus sp. nov. found inside a pine cone.

Figure 31. Phylogenetic tree based on the concatenated 16 S rDNA and COX 1 mtDNA loci. Posterior probabilities of nodes are shown (as percentages) on the branches. Different colours are used to indicate the newly described species. Scale bar corresponds to substitutions per site.

Figure 32. Maps of the known geographic ranges of the species treated herein.