Centruroides koesteri Kraepelin, 1911

de Armas, Luis F., 2019, Identity of the Central American scorpion Centruroides mahnerti Lourenço, 1983 (Scorpiones: Buthidae), Euscorpius 293, pp. 1-4 : 1

Centruroides koesteri Kraepelin, 1911

( Figures 1–4, 8)

Centruroides koesteri Kraepelin, 1911: 72 ; Fet & Lowe, 2000: 111 (complete references list); Teruel & Stockwell, 2002: 114.

= Centruroides mahnerti Lourenco, 1983: 763 (syn. by Armas & Maes, 2001: 16).

COMMENTS. The Central American scorpion Centruroides mahnerti Lourenço, 1983 , named in honour of Dr. Volker Mahnert (1943–2018), was described on the basis of a female holotype (not a male as appears in Fet & Lowe, 2000: 112) and two female paratypes from Momotombo Volcano (12°25’N 86°33’W; 80 m a. s. l.), León Department, Nicaragua. This species was downgraded by Armas & Maes (2001) to a junior synonym of C. koesteri Kraepelin, 1911 ; however,Teruel & Stockwell (2002: 114) argued that description and figures given for C. mahnerti are also referable to juveniles of C. edwardsii (Gervais, 1843) . Unfortunately, neither Armas & Maes (2001) nor Teruel & Stockwell (2002) examined the type specimen of C. mahnerti ; additionally, the habitus of this species was illustrated on the basis of two poorly defined photos (dorsal and ventral aspects) of a paratype ( Lourenço, 1983: 764, figs. 1–2). Taking in account such uncertainty, Borges et al. (2012: 131, 132, table 1) preferred retaining C. mahnerti as a valid species.

To elucidate this problem, photogaphs of the type specimen of C. mahnerti ( Figs. 1–4) were examined and now is possible to confirm that, as stated by Armas & Maes (2001), this species is really a junior synonym of C. koesteri . Juvenile specimens of C. edwardsii (Figs. 5–7) clearly differ from those of C. koesteri , among other characters, by having a darker general pattern, the pedipalps very densely hirsute and metasomal segments II-IV with stronger spinoid granules on dorsal carinae and having three or four pairs of ventrolateral macrosetae (only two pairs in C. koesteri ). On the other hand, the holotype of C. mahnerti is a subadult female, perhaps of two instars less than the adult female holotype of C. koesteri , as inferred from measurements given by Francke & Stockwell (1987: 10); also, its pedipalp chela is slender than the pedipalp patella, whereas in the adults of C. koesteri it is other way round ( Francke, 1978; Teruel & Stockwell, 2002).

As pointed out by Lourenço (1983: 767) and Francke (1978: 70), C. koesteri and C. edwardsii (misidentied as C. margaritatus by authors previous to Armas et al., 2011) are sympatric species, but the former appears to be arboreal in habits ( Francke, 1978: 70), although in the Momotombo Volcano area both species were found inside buildings. From the same area, Lourenço (1983) and Armas (1995) also recorded the diplocentrine scorpion Didymocentrus krausi Francke, 1978 .

According to present-day data (Francke & Stockwell, 1987; Armas & Maes, 2000; Teruel & Stockwell, 2002), C. koesteri ranges from the Fonseca Gulf (southern Honduras) to northwestern Costa Rica ( Fig. 8), mainly in tropical semiarid environments.