Centruroides bicolor (Pocock, 1898)

Figures: 1; 7 A, B; 10 A, C; 11 A; 14 A; 16 A, B; 19 A, B.

Tables: 1, 6, 7.

References subsequent to Fet & Lowe (2000: 101): Borges et al., 2012; Quintero & Esposito 2014; Miranda et al., 2014; Miranda et al., 2015; Salazar et al., 2018; Armas & Miranda, 2019: 53, figs. 6–7; Escudero-Sanjur et al., 2022; Lezcano et al., 2022; Morán-González et al., 2025; Youngs-Mitre et al., 2025, Samudio et al., 2025.

Type material: Female holotype: Costa Rica, Pozo Azul de Piris, (NHMUK), lost or destroyed. A male from Panama, without precise locality, was designated as the neotype by Francke & Stockwell (1987: 8), but there is no collector’s name or date (NHMUK).

Material examined.

BOCAS DEL TORO: Changuinola: Manila, intradomiciliary, 1 male, 20 June 2019, coll. B. Jaén (CoZEMICGES); Deborah, under stone, 1 female, 16 May 2012, coll. L. Nuñez (MIUP). CHIRIQUÍ: Alanje: Alanje, on the banks of the river, 2 males, 3 females, 1 juv., 20 September 2019, coll. R. Serrano (CoZEM-ICGES); 2 juv., 22 September 2019, coll. J. Lezcano (CoZEM-ICGES); on a log, 1 female, 26 June 2014, coll. S. Chavez (MIUP). Barú: Baco, San Valentín, 1 male, 11 February 2019, coll. F. Acosta (CoZEM-ICGES). Boquerón: Boquerón, 1 female, 8 October 2010, coll. R. Miranda, S. Bermúdez; Ojo de Agua, 2 males, 1 female, 28 January 2009, coll. R. Miranda, S. Bermúdez (CoZEM-ICGES); Santa Rita, 1 male, 15 July 2007, coll. F. Guerra. Boquete: Boquete, 1 female, 20 February 2007, coll. D. Correa (MIUP); Boquete, under wood, 1 female (with 50 juv.), 5 November 2010, coll. R. Gabriel (MIUP); Boquete, inside a house, 1 male, 1 female, 3 juv., 2 May 2015, coll. D. Atencio (MIUP); Alto Boquete, El Francés, inside a house and a warehouse. 2 males, 19 July 2012, coll. M. Guarnizo (MIUP); Caldera, 1 ind., 5 July 2014, coll. G. García (CoZEM-ICGES); Caldera, 1 male, 15 March 2021, coll. C. Pittí (CoZEM-ICGES); Palmira Abajo, 1 female, 19 November 1995, coll. I. Sanjur (MIUP). Bugaba: Bugaba, under bed, 1 male, 28 August 2012, coll. M. Herrera (MIUP); Río Mula, near Bugaba cemetery, 1 juv., 2 November 1985, coll. D. Quintero, R. Cambra (MIUP); Bugaba, 2 males, 2 females, 5 juv., 2 November 1985, coll. D. Quintero, R. Cambra (MIUP); Bugaba, inside a dry macano trunk, 3 males, 2 females, 1 juv., 13 May 1984, coll. M. Ríos (MIUP); Bugaba, 2 males, 2 juv., 1 April 2004, coll. R. Miranda (MIUP); Bugabita, 2 males, 22 August 2010, coll. A. Estribí; Bugabita, on the porch of a house, 1 male, 19 July 2014, coll. C. Pinto (MIUP). El Bongo, inside a dry macano trunk, 1 male, 6 July 2014, coll. A. Santamaría (MIUP); La Concepción, 1 male, 1 female, 1 juv., 2 November 1978, coll. M. Guerra (MIUP); La Concepción, 1 male, 20 June 2007, coll. S. Bermúdez (MIUP); La Estrella, 1 male, 21 July 2012, coll. J. Espinosa (MIUP); San Andrés, 1 male, 28 March 2008, coll. R. Cambra (MIUP); San Andrés, among the shoes inside the house, 1 male, July 2012, coll. M. Estribí (MIUP). David: Chirigagua, 1 male, 18 March 2019, coll. A. Rodríguez (CoZEM-ICGES). David, 2 females, 1 juv., October 1975, coll. D. Quintero (MIUP). Las Lomas: 1 female, 29 March 2004, coll. R. Miranda (CoZEM-ICGES); Las Lomas, 1 female (with 9 juv.), 1 April 2004, coll. R. Miranda (CoZEM-ICGES); Las Lomas, 1 juv., 23 January 2009, coll. R. Miranda (CoZEM-ICGES). Puerto Pedregal, 1 male, 1 female, 9 December 1979, coll. D. Vinda (MIUP); San Pablo, on wall, 1 male, 1 female, 9 January 2014, coll. A. Miranda (MIUP); Terronal, in rotten tree, 19 November 2012, coll. C. González (MIUP). Dolega: Balita: 1 male, 2 females, 11 January 2010, coll. A. Araúz (MIUP); Balita, 1 male, 3 juv. 29 May 2010, coll. A. Araúz (MIUP); Balita, 1 male, 2 females, May 2010, coll. A. Araúz (MIUP); Balita, 1 female, 31 December 2011, coll. A. Araúz (MIUP); Balita, 1 male, 21 January 2012, coll. A. Araúz (MIUP); Balita, 1 female, 12 November 2012, coll. A. Araúz (MIUP). Balita, Tinajas, 1 female, 22 April 2012, coll. A. Araúz (MIUP). Balita: on the wall of an abandoned bathroom, next to a sugarcane mill, 1 male, 17 March 2012, coll. A. Araúz (MIUP); Balita, on the bathroom wall and adjacent to the bedroom, 2 males, 18 March 2012, coll. A. Araúz (MIUP); on the external wall of the house, 2 males, 24 March 2012, coll. A. Araúz (MIUP); Balita, under dry tree bark, 1.5 m from the ground, near to Quebrada Sábalo, 1 male, 31 March 2012, coll. A. Araúz (MIUP); Balita, under dry tree bark, 1 male, 1 female, 8 April 2012, coll. A. Araúz (MIUP); Balita, in a warehouse, 2 males, 1 juv., 8 April 2012, coll. A. Araúz (MIUP); Balita, on the internal wall of the house, 1 female, 18 November 2012, coll. A. Araúz (MIUP); Potrerillos Abajo, 1 female, 14 April 2012, coll. A. Araúz (MIUP); Potrerillos Abajo, 1 juv. 22 April 2012, coll. A. Araúz (MIUP); Potrerillos Abajo, under saddle, 1 male, 24 November 2012, coll. A. Araúz (MIUP); Potrerillos Abajo, at the base of a dry trunk, 1 male, 1 female. 15 March 2015, coll. A. Araúz (MIUP); Potrerillos Arriba, in an abandoned beehive, 1 female, 24 February 1986, coll. M. Tem (MIUP); Potrerillos Arriba, Alto Candanedo, 1 male, 28 March 2011, coll. P. Candanedo (CoZEM-ICGES); Potrerillos Arriba, 1 individual, 24 July 2012, coll. S. Arizala. Gualaca: Gualaca, in trunk, 1 male, 1 female, 25 August 2012, coll. A. Miranda, M. Alvarado (MIUP); Gualaca, inside a traditional stove, 1 male, 1 female, 25 August 2012, coll. J. Valdés, M. Quirós (MIUP); Hornito, Valle de Las Minas, 1 female, 14 January 2013, coll. R. Gabriel (MIUP). Puerto Armuelles: Monteverde, 1 male, 5 August 1996, coll. A. Rodríguez (MIUP; Puerto Armuelles, 1 male, 1 juv., 29 July 2012, coll. M. Caballero (MIUP). Remedios: Sur de Remedios, 1 male, 2 females, 15 August 1982, coll. D. Quintero (MIUP). Renacimiento: Caizán, 1 female, 31 August 2012, coll. B. Lezcano (MIUP); Caizán, in logs, May 2014, coll. J. Araúz (MIUP); Caizán, behind drawers, 1 female, 22 June 2014, coll. C. Navarro (MIUP); Caizán, 1 female, 25 July 2014, coll. D. Ortega (MIUP); Caizán, La Primavera, 1 juv., 4 July 2016, coll. M. Amador (MIUP). Los Planos, 1 individual, October 2017, coll. D. Araúz (CoZEM-ICGES). Río Sereno, 1 female, 30 June 2018, no collector name (MIUP). San Félix: San Félix, on a stick in a pasture, 1 male. 1 female, 15 August 1982, coll. D. Quintero (MIUP); San Félix, 2 males, 25 June 2007, coll. E. Adames (MIUP); Hospital de San Félix, 2 males, 4 July 2017, coll. A. Concepción (CoZEM-ICGES, DIEM2017-0020). San Juan: San Juan, 1 female, 22 July 2017, no collector name (MIUP). San Lorenzo: El Jobo, 1 male, 19 October 1984, coll. T. De Gracia (MIUP). Tierras Altas: Cerro Punta, in a warehouse, 1 female, 28 June 2014, coll. E. González (MIUP). Paso Ancho, inside a house, 1 male, 15 June 2012, coll. J. Araúz (MIUP); Volcán, 2 males, 1 juv., 3 May 2010, coll. M. Valdez (MIUP); El Valle, 1 male, 27 June 2012, coll. I. Zapata (MIUP); El Valle, 1 male, 1 female, 14 July 2012, coll. J. Beitía (MIUP); Brisas del Norte, in the living room of a house, 1 female, 14 October 2013, coll. K. Wing (MIUP); Brisas del Norte, in the yard, 1 female, 5 July 2014, coll. D. Samudio (MIUP). Tolé: Tolé, 1 male, November 1979, coll. E. Adames (MIUP); Las Meregildas, in a shirt inside the house, 1 male, 14 August 2012, coll. A. Miranda (MIUP). COCLÉ: Aguadulce: in a dry, rotten trunk, 1 female, November 1982, coll. D. Ramos (MIUP). COLÓN: Colón: Sabanitas, Barriada Champion, 1 male, 17 January 1988, coll. M. Mitre (MIUP). COMARCA NGÄBE-BUGLÉ: Besikó: Boca de Remedio, on wooden wall (house), 1 female, 30 June 2014, coll. D. Zurdo (MIUP); Nämnoní, Altos de Piedra, on wall of house, 1 female, 16 August 2012, coll. I. Montezuma (MIUP); Soloy, on trunk, 1 female, 1 July 2014, coll. A. Palacios (MIUP). HERRERA: Los Pozos: La Arena de los Pozos, piece of tree trunk, 13 June 2008, coll. M. Ávila (Control de vectores) (CoZEMICGES). Ocú: El Tijeras, under leaf litter, 1 male, 9 September 2020, coll. M. Ávila (Control de vectores) (CoZEMICGES); Limón de Tijeras, under leaf litter, 1 male, 9 September 2020, coll. J. B. Navarro (CoZEM-ICGES); Ocú, under wood, 1 juv., 8 September 2020, coll. J. B. Navarro (CoZEM-ICGES). PANAMA: Panamá: San Martín, Carriazo, inside the bathroom, dead due to fumigation, 1 male, 19 December 2017, coll. A. Castro (CoZEM-ICGES). La Exposición, ICGES, Infrastructure department staff, 1 male, 15 March 2016, coll. Sr. David (CoZEM-ICGES). Ancón, Clayton, inside a house, 1 juv., 27 August 2007, coll. Prof. Murillo (MIUP). Chilibre: Calzada larga, Barriada Las Albinas, 1 female, 1 male, 20 April 2002, coll. N. Rosas (CoZEM-ICGES); Juan Díaz, Costa del Este, stung a young person, 1 female, 21 June 2010, coll. Dr. Sosa (CoZEM-ICGES). VERAGUAS: La Mesa: La Mesa, 1 juv., 23 February 2009, coll. R. Fuentes (CoZEM-ICGES). Atalaya: Atalaya, in living room, crushed, 1 male, 03 April 2018, coll. L. Abrego (CoZEM-ICGES); La Carrillo, 1 male, 12 January 2017, coll. M. Rodríguez. Cañazas: San Juan, 1 female, 22 August 1987, coll. D. Quintero (MIUP); Río Rita, road to Los Panamaes, 1 male, 18 July 1982, coll. D. Quintero (MIUP); Palo Verde, 7 km from the Inter-American Highway towards Cañazas, under a rotten trunk, 1 male, 1 female, 4 to 6 August 1982, coll. D. Quintero (MIUP). Las Palmas: under the bark of trunks, pasture fences and rotten trees, 7 females, 2 males, 2 juv., 2–5 August 1982, coll. D. Quintero (MIUP). Mariato: Parque Nacional Cerro Hoya, 1 individual, 13 April 2011 (CoZEM-ICGES). Montijo: El Bongo, under logs in a pasture, 2 juv., 20 June 1982, coll. D. Quintero (MIUP); Coiba Island, 1 female, 3 December 1998, coll. R. Cambra (MIUP); Isla Coiba, 1 male, April 1995, coll. I. De La Riva (MIUP); Coiba Island, in the root of a mango tree, 1 male, 1 female, 23 January 1994, coll. J. L. Nieves (MIUP); Coiba National Park, Coiba Island, Campamento central, 1 male, 27 November 2010, coll. R. Miranda (CoZEM-ICGES); Coiba National Park, Coiba Island, 1 female, 27 February 2011, coll. R. Miranda (CoZEM-ICGES); Coiba National Park, Coiba Island, 29 November 2010, coll. R. Miranda (CoZEM-ICGES); Coiba National Park, Coiba Island, 1 female, 16 April 2012, coll. R. Miranda (CoZEMICGES); Coiba National Park, Coiba Island, 1 female, 16 April 2012, coll. R. Miranda (CoZEM-ICGES); Coiba National Park, Coiba Island, 1 male, 16 April 2012, coll. R. Miranda, J. Cleghorn (CoZEM-ICGES); Coiba National Park, Coiba Island, 1 female, 21 February 2011, coll. R. Miranda (CoZEM-ICGES); Coiba National Park, Coiba Island, 1 juv., 27 November 2010, coll. R. Miranda (CoZEM-ICGES); Coiba National Park, Coiba Island, Ministerio de Ambiente Station, 3 females, April 2012, coll. R. Miranda (CoZEM-ICGES); Coiba National Park, Coiba Island. 1 female, May 2012, coll. R. Miranda (CoZEM-ICGES); Coiba National Park, Coiba Island, Los Monos trail, 1 female, 12 February 2019, coll. J. Lezcano, S. Muñoz, S. Bermúdez (CoZEM-ICGES); Coiba National Park, Ranchería Island, 2 males, 2 juv., 11 February 2019, coll. J. Lezcano, S. Muñoz, S. Bermúdez (CoZEM-ICGES); Coiba National Park, Ranchería Island, 1 male, 12 February 2019, coll. J. Lezcano, S. Muñoz, S. Bermúdez (CoZEMICGES); Coiba National Park, Ranchería Island, 1 juv. 12 February 2019, coll. J. Lezcano, S. Muñoz, S. Bermúdez (CoZEM-ICGES); Coiba National Park, Ranchería Island, among the rocks, 1 juv., 11 February 2019, coll. J. Lezcano, S. Muñoz, S. Bermúdez (CoZEM-ICGES); 1 juv., 12 February 2019, coll. J. Lezcano, S. Muñoz, S. Bermúdez (CoZEM-ICGES); Coiba National Park, Ranchería Island, 1 juv., 12 February 2019, coll. J. Lezcano, S. Muñoz, S. Bermúdez (CoZEM-ICGES); Coiba National Park, Ranchería Island, 1 female, November 2019, coll. L. Domínguez, S. Bermúdez (CoZEM-ICGES); Coiba National Park, Jicarón Island: beach edge, 1 male, 29 March 2017, coll. C. Monteza (MIUP); Puerto Mutis, at the sawmill, northwest of Puerto Mutis, under planks near the mangroves, 1 juv., 28 June 1982, coll. D. Quintero (MIUP). Ponuga: Cirbulaco, in pastures, under fallen logs, 1 male, 6 females, 2 juv., 8–13 November 1982, coll. J. Palavicini (MIUP); El Suay, Carretera Ponuga-El Suay, under a trunk and stones, 1 female, 2 juv., 01 August 1982, coll. D. Quintero (MIUP). Río de Jesús: Río de Jesús, 1 female, 11 April 2018, coll. M. Jordan (CoZEM-ICGES); Río de Jesús, under a rotten palm tree trunk on the ground, 1 male, 7 June 1982, coll. D. Quintero (MIUP); Las Huacas, 1 male, 7 September 2018, coll. A. Pineda (CoZEM-ICGES). San Francisco: Carabalí, Carretera Santiago- Santa Fe, 1 juv., 24 March 2005, coll. R. Miranda (MIUP). Santa Fe: Santa Fe, 1 female, 10 December 1982, coll. D. Quintero (MIUP); Santa Fe, on sticks in pastures, under the bark of rotten trunks and inside houses, 7 females, 2 juv., 14–17 July 1982, coll. D. Quintero (MIUP); Santa Fe, 7 females, 10 December 1982, coll. D. Quintero (MIUP); Santa Fe, 2 females, 1 male, 2 juv., 1–3 December 1982, coll. D. Quintero (MIUP): Santa Fe, on the walls of a house, 2 individuals, 22 February 2006, coll. F. Ríos (control de vectores) (CoZEM-ICGES); Santa Fe, was used for DNA extraction, December 2014, coll. R. González (CoZEMICGES); Santa Fe, on the way to Cerro Tute, under tree bark, 1 male, 1 female, 26 March 1999, coll. A. Aizprúa (MIUP); Santa Fe, on the way to Cerro Tute, under tree bark, 1 female, 26 March 1999, coll. A. Aizprúa (MIUP); Santa Fe, El Pantano, El Palmar, intradomiciliary, 1 female, 10 May 2017, coll. D. Archibold (CoZEM-ICGES); in palm, 2 individuals, 3 September 2008, coll. R. Torres (CoZEM-ICGES); Santa Fe, El Pantano, 1 male, 6 May 2017, coll. D. Archibold (CoZEM-ICGES); Santa Fe, peridomiciliar, 1 female, 22 May 2017, coll. D. Archibold (CoZEMICGES); Santa Fe, Altos de los Pinedas, 1 September 2006, coll. R. Torres (CoZEM-ICGES); Carretera El Alto, 1 male, 21 June 2017, coll. R. Miranda, J. Lezcano, S. Bermúdez (CoZEM-ICGES); Carretera El Alto, 1 female, 24 June 2017, coll. R. Miranda, J. Lezcano, S. Bermúdez (CoZEM-ICGES); Carretera El Alto, on tree, 1 male, 24 June 2017, coll. R. Miranda, J. Lezcano, S. Bermúdez (CoZEM-ICGES); Carretera El Alto, on a tree 1 meter above the ground, 1 female, 24 June 2017, coll. R. Miranda, J. Lezcano, S. Bermúdez (CoZEM-ICGES); Carretera El Alto, on a tree 1.70 meters above the ground., 1 female, 24 June 2017, coll. R. Miranda, J. Lezcano, S. Bermúdez (CoZEMICGES); Carretera El Alto, on a tree 1 m above the ground., 1 female, 24 June 2017, coll. R. Miranda, J. Lezcano, S. Bermúdez (CoZEM-ICGES); in palm, 1 juv., 3 September 2008, coll. R. Torres (CoZEM-ICGES); inside a house, 22 February 2008, coll. F. Pineda (control de vectores) (CoZEM-ICGES); Alto de Piedra, Parque Nacional Santa Fe, 1 female, 2 June 1014, coll. D. Correa (MIUP); Estación Alto de Piedra, 1 male, 2 June 2014, coll. D. Correa (MIUP); Estación Alto de Piedra, 1 juv., 13 November 1999, coll. A. Santos (MIUP); Las Lajas, 1 female, 7 September 2018, coll. A. Pineda (CoZEM-ICGES). Santiago: La Huaca, Santa María, 1 juv., 15 November 2015, coll. T. Sosa (CoZEM-ICGES); Urracá, Tierra Hueca, in palm, 1 male, 17 February 2017, coll. F. Pineda (Control de vectores) (CoZEM-ICGES); Santiago, 1 male, 17 February 2017, coll. F. Pineda (Control de vectores) (CoZEMICGES). Soná: walls and patio of three ranches, 5 males, 3 females, 4 juv., 2 to 4 May 1984, coll. R. Abrego (MIUP); La Soledad, 1 male, 23 April 2008, coll. V. Martínez (MIUP); La Soledad, 1 male, 23 to 24 April 2008, coll. V. Martínez (MIUP); La Soledad, 1 juv., 23 to 24 April 2008, coll. V. Martínez (MIUP); 1 male, 23 to 24 April 2008, (MIUP); Bahía Honda, Lerén, in epiphyte, 1 juv., 12 December 2001, coll. R. Miranda, R. Cambra, A. Santos (MIUP); Bahía Honda, Isla Canales de Tierra, 2 juv., 14 December 2001, coll. R. Miranda, R. Cambra, A. Santos (MIUP); Bahía Honda, Isla Canales de Tierra, 1 male, 2 females, 14 December 2001, coll. R. Cambra, A. Santos (MIUP); Bahía Honda, 1 male, 1–4 March 2002, coll. A. Santos, P. González (MIUP); Bahía Honda, Playa Limón, 1 juv., 7 August 2001, coll. D. Quintero (MIUP); Bahía Honda, Playa del Sol, 1 male, 6–18 December 2001, coll. R. Miranda, R. Cambra, A. Santos (MIUP); Bahía Honda, 2 males, 3 juv., 28 May–2 June 2002, coll. R. Miranda, R. Cambra, A. Santos (MIUP); Bahía Honda, 3 males, 2 females, 3 juv., 8 August 2001, coll. A. Santos (MIUP); Bahía Honda, in epiphyte, 2.5 m from the ground, 1 juv., 9 December 2001, coll R. Cambra, A. Santos (MIUP); Bahía Honda, 3 males, 2 juv., 28 May–2 June 2002, coll. R. Miranda, R. Cambra, A. Santos (MIUP); Bahía Honda, Salmonete, 1 male, 1 female, 13 August 2001, coll. A. Santos, F. Cedeño (MIUP); Santa Catalina, 1 male, 1 female, August 1982, coll. K. Myers (MIUP).

Diagnosis. Follows Francke & Stockwell (1987), Quintero & Esposito (2014) and own data.

Large scorpions, total body length between 92 and 160 mm. Colouration: Colour pale yellow in the legs, femur and patella of pedipalp and segments I-IV of metasoma, other parts black: carapace, tergites I-VI, segment V of the metasoma and telson, granules of the metasomal carinae, apex of the pedipalp patella, and chela of the pedipalp. Carapace: moderately granular.Anterior margin with coarse, blunt granules; small, pointed granules on the posterior margin. Lateral ocular tubercles with three macro-ocelli each. ocular tubercle with granular superciliary carinae (costate granular in female); lateral ocular carinae present and moderate granular; posteromedian carinae present and crenate; anterior median furrow wide and moderately deep, posterior median furrow narrow and posteriorly deep; posterior marginal furrow shallow and wide. Pectines: pectinal tooth count 23–29 (mode= 26) in females and 25–28 (mode= 27) in males; basal plate rectangular. Mesosoma: tergites moderately granular, posterior margin with small conical granules; median carina crenate, present on all tergites; tergite VII pentacarinate, with crenate carinae. Pedipalp: orthobothriotaxic, type A, sparsely hirsute. Femur and patella with carinae granulate, internal faces tuberculate. The chela is 4.5 to 5 times longer than it is wide and 1.1 to 1.2 times wider than the patella, in both females and males. Chela with six distinct carinae: dorsal marginal carina moderately granular; dorsal secondary carina densely granular and smooth; digital carina vestigial to obsolete; dorsal internal carina vestigial with scattered very small granules; ventroexternal carina weakly, smooth or granular; ventrointernal vestigial, granular. Fixed and movable digits of the pedipalp chela with nine primary rows of denticles; fixed finger with shallow notch; mobile finger with moderately developed basal lobe. Metasoma: metasomal segments exhibit 10-8-8-8-5 well-developed carinae, moderately granulose; segment V between 2.3 to 2.6 times longer than wide in females, and between 3 to 3.5 times in males; segments II-IV with two pairs of ventrolateral macrosetae. Intercarinal spaces coriaceous and fine granular denser in the IV segment. Telson with vesicle ovate in females and oblong in males, with the aculear tubercle moderate and spiniform, directed toward the apex of the aculeus.

Distribution: Costa Rica (Puntarenas) and Panama. In Panama, C. bicolor is widely distributed in the provinces of Chiriquí and Veraguas, with populations confirmed on some islands of the Gulf of Chiriquí (Coiba, Jicarón and Ranchería) and some peripheral populations in the provinces of Herrera and Coclé. Isolated records from the provinces of Bocas del Toro and Colón on the Caribbean coast of the country, as well as from the scattered data from Panama Province are likely due to accidental human transport from sites where they are abundant and do not represent established populations.

Variation: Quintero and Esposito (2014) mention that males of this species can measure up to 160 mm. Quintero & Esposito (2014) and Armas & Miranda (2019) report the discovery of some darker specimens in populations near the Volcán Barú and on Coiba Island (Pacific).

Remarks: This species was described from Pozo Azul de Piris, Santo Domingo de Golfo Dulce, Costa Rica (Pocock, 1898). Lourenço & Méndez (1984) did not review the type material of this species, but instead reviewed two specimens from Panama deposited at the NHMUK, and stated the probability that it was a race of C. gracilis. The neotype designated by Francke & Stockwell (1987) was not examined for this study.

Natural history: This species is primarily associated with the bark and holes of large fallen logs (Miranda, 2011). They have also been found inside and around houses (Quintero, 2005; Quintero & Esposito, 2014). It is sympatric with Centruroides panamensis (Quintero & Esposito, 2014). They have been observed feeding on insects and reptiles (Miranda et al., 2015). Among their predators are reptiles (Squamata) such as Stenorrhina degenhardtii (Berthold, 1846) (Solórzano, 2018) and Thecadactylus rapicauda (Houttuyn, 1782) (Cubas-Rodríguez & Armas, 2024).

Reproductive biology: Births have been registered in March, July–August, and October in conditions of laboratory. Average litter size of 25 ± 12 offspring by parturitions in Panama (Lezcano et al., 2022) and 40 ± 5 offspring by parturitions in Costa Rica (Triana & Bonilla, 2023). However, in field observations, there may be up to 50 offspring (Quintero & Esposito, 2014).

Venom and scorpionism: Salazar et al. (2018) analysed the venom of several Buthidae scorpions from Panama using HPLC technique, including that of C. bicolor. These researchers found that several components of C. bicolor venom exhibited moderate to lethal effects when tested on mice and insects. Samudio et al. (2025) characterized C. bicolor venom through transcriptomic (venom gland) and proteomic (crude venom) analyses, discovering that many venom components were detected with both methods, including neurotoxins that target Na+ and K+ channels, hyaluronidase, CRISP proteins, and metalloproteinases; however, some components were identified only through the transcriptomic approach for the first time and had not been previously detected in the proteome, such as nucleobindin and angiotensin-converting enzymes. Morán-González et al. (2025) evaluated the effect of venom from Panamanian scorpions of the genera Centruroides and Tityus. These researchers injected five scorpion venoms intravenously into mice (CD-1 strain; 18–20 g) individually, at doses ranging from 0.5 to 1.5 LD50 for each venom. They found that, among the venoms tested, C. bicolor venom caused the greatest increase in glucose and amylase levels, suggesting potential damage to the pancreas. Among the material reviewed, there was one record of C. bicolor involved in a case of scorpionism, which occurred in Panama City without serious consequences.