Buthus prudenti, Lourenço & Leguin, 2012

Lourenço, Wilson R. & Leguin, Elise-Anne, 2012, A new species of the genus Buthus (Scorpiones: Buthidae) from northern Cameroon, Euscorpius 152, pp. 1-9 : 3-8

Buthus prudenti sp. n. ( Figs. 1–14)

Type material: Cameroon, Region of Sanguéré-Djoi (9°23.229’N 13°500.68’E), 1 male holotype, 7 males and 8 females paratypes (P. Prudent leg.), August- November 2011. Cotton field, scorpions collected with Barber traps. Holotype and 11 paratypes deposited in the Muséum national d’Histoire naturelle, Paris, France. 4 paratypes deposited in the collections of the CIRAD, UMR CBGP ( INRA /IRD/Cirad/Montpellier SupAgro).

Etymology: patronym in honor of Dr. Patrick Prudent, CIRAD / IRAD, Garoua, Cameroon, who collected the material described as the new species.

Diagnosis

Scorpions of medium to large size, in relation to the species of the genus, reaching a total length of 63 mm for males and 62 mm for females. General coloration yellow to reddish-yellow; in some specimens tergites and sternites can be darker, more to brownish. Pedipalps and legs yellow. Chelicerae yellow with fingers’ teeth almost blackish. Carinae and granulations strongly marked on carapace and tergites; moderately marked on metasomal segments. Furrows on carapace strongly marked and deep. Fixed and movable fingers with 12 rows of granules in males and 11 on females. Pectines with 27 to 29 teeth in males, 25 to 29 in females. Male pectines just touching, but not overlapping in their proximal region.

Description (based on male holotype and one female paratype; measurements see Table 1).

Coloration. Basically yellow to reddish-yellow; in some specimens, tergites and sternites are darker, more to brownish. Prosoma: carapace reddish-yellow; eyes surrounded by black pigment. Mesosoma: tergites reddish-yellow with the carinae and granulations slightly darker. Metasomal segments and vesicle yellowish; aculeus yellowish at its base and dark reddish at its extremity. Venter reddish-yellow. Chelicerae yellowish without any variegated spots; fingers yellowish with blackish teeth. Pedipalps: yellowish with some carinae slightly reddish; chela fingers with the oblique rows of granules blackish. Legs yellowish with some vestigial infuscate spots.

Morphology. Carapace strongly granular; anterior margin slightly convex on male and almost straight on female. Carinae strongly marked; anterior median, central median and posterior median carinae strongly granular; ‘lyre’ configuration well marked. All furrows strong and deep. Median ocular tubercle almost in the centre of carapace. Eyes separated by almost three ocular diameters. Four pairs of lateral eyes: the first three of moderate size, the last one only vestigial. Sternum triangular, wider than long. Mesosoma: tergites with strong and intense granulation. Three longitudinal carinae strongly crenulate in all tergites; lateral carinae reduced in tergite I. Tergite VII pentacarinate. Venter: genital operculum divided longitudinally and formed by two semi triangular plates. Pectines: pectinal tooth count 27-28 in male holotype and 28- 28 in female paratype; middle basal lamella of the pectines not dilated; male pectines just touching but not overlapping in their proximal region. Sternites smooth, with elongated spiracles; four carinae on sternite VII; sternite VI with two weak carinae next to the spiracles; other sternites without carinae and with two moderately marked furrows. Metasomal segments I to III with 10 moderate carinae; segment IV with 8 moderate carinae; intermediate carinae incomplete on segments II and III; ventral carinae more strongly marked on segments II to IV, particularly in female; segment V with five carinae; the ventrolateral carinae crenulate with 2–3 lobate denticles posteriorly; ventral median carina only slightly divided posteriorly; anal arc composed of 8–9 ventral teeth, and two lateral lobes. All segments with a smooth dorsal depression; intercarinal spaces weakly granular, except for the ventral aspect of segment V which presents a thin intense granulation and some larger granules. Telson almost smooth on male and with some granulations on female; aculeus strongly curved, slightly shorter than the vesicle; subaculear tooth absent. Cheliceral dentition as defined by Vachon (1963) for the family Buthidae ; external distal and internal distal denticles of approximately the same length; basal denticles of movable finger small but well distinct; ventral aspect of both fingers and manus covered with long dense setae. Pedipalps: femur pentacarinate; patella with eight carinae; chela smooth with only vestigial carinae; all faces weakly granular to smooth. Fixed and movable fingers with 12-12 oblique rows of granules in most males, 11- 11 in females; some males may present also 11-11 rows. Internal and external accessory granules present and moderate; three accessory granules on the distal end of movable finger next to the terminal denticle. Legs: tarsus with two longitudinal rows of 8-10 long setae ventrally; tibial spur strong on legs III and IV; prolateral spurs moderate to strong on legs I to IV. Trichobothriotaxy: trichobothrial pattern of Type A, orthobothriotaxic as defined by Vachon (1974). Dorsal trichobothria of femur arranged in β- configuration (Vachon, 1975).

Relationships

Buthus prudenti sp. n. can be associated with the “ Buthus occitanus ” complex of species. It can be distinguished from other Buthus species and in particular from Buthus elhennawyi , the most geographically close species, by the following characters: (i) Much bigger total size and different morphometric values; see Table 1 and Lourenço (2005c); (ii) male pectines in B. prudenti sp. n., do not overlap in their proximal region, whereas they overlap strongly in males of B. elhennawyi ; the number of pectinal teeth in B. prudenti sp. n. is also lower than in B. elhennawyi ; (iii) furrows in carapace are more strongly marked in the new species; (iv) male telson of B. prudenti sp. n., is almost smooth without any subaculear tooth.

Habitat of the New Species

The area in which Buthus prudenti sp. n. was collected is the transitional zone between the Sahel and savannah formations ( Fig. 15–17). Most of these natural formations have been replaced in recent years by agriculture activities. The new species was collected in cotton fields, with the help of Barber traps used to test the efficacy of seed treatment. In present days, most of the area of the Senguéré-Djoi is used for agriculture, but some parcels can also be replaced by others composed of bushes ( Figs. 16–17).

Two other scorpion species have also been collected in the northern Cameroon, but in older times when large parcels of the natural environment were yet present: Leiurus savanicola Lourenço, Qi et Cloudsley-Thompson, 2006 and Scorpio savanicola Lourenço, 2009 (Lourenço et al., 2006; Lourenço, 2009). It is quite possible, however, that with increasing anthropic action on the environment, most scorpion species will know an important regression of their populations. Only more opportunistic species, what seems to be the case of Buthus prudenti sp. n., will see their populations expand and colonize most of the area (Lourenço, 1991).