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Juan Carlos Valenzuela-Rojas
Programa de Licenciatura en Ciencias Naturales y Educación Ambiental. Facultad de Educación. Universidad Surcolombiana. Neiva, Huila, Colombia

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Journal article
Published: 01 June 2020 in The Journal of Arachnology
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Phoneutria Perty, 1833 is considered one of the most toxic spider genera in the world; however, the natural history and biology of these spiders is still largely unexplored. The objective of this study was to determine the natural diet of the medically important species Phoneutria boliviensis (F.O.P.-Cambridge, 1897) based on prey records from Colombia, and supplemented by published records found in electronic databases as well as photographic records from the internet. We found that P. boliviensis is an euryphagous predator with a broad diet made up predominantly of arthropods (orders Araneae, Blattodea, Coleoptera, Hymenoptera, Lepidoptera, Mantodea, Orthoptera, and Phasmatodea) and to a lesser extent of small vertebrates (Gekkonidae, Hylidae, and Sphaerodactylidae). These results support previous evidence suggesting that P. boliviensis is a generalist predator that includes both invertebrates and small vertebrates in its diet.

ACS Style

Juan Carlos Valenzuela-Rojas; Julio César González-Gómez; Giovany Guevara; Lida Marcela Franco; Gladys Reinoso-Flórez; Luis Fernando García. Notes on the feeding habits of a wandering spider, Phoneutria boliviensis (Arachnida: Ctenidae). The Journal of Arachnology 2020, 48, 43 -48.

AMA Style

Juan Carlos Valenzuela-Rojas, Julio César González-Gómez, Giovany Guevara, Lida Marcela Franco, Gladys Reinoso-Flórez, Luis Fernando García. Notes on the feeding habits of a wandering spider, Phoneutria boliviensis (Arachnida: Ctenidae). The Journal of Arachnology. 2020; 48 (1):43-48.

Chicago/Turabian Style

Juan Carlos Valenzuela-Rojas; Julio César González-Gómez; Giovany Guevara; Lida Marcela Franco; Gladys Reinoso-Flórez; Luis Fernando García. 2020. "Notes on the feeding habits of a wandering spider, Phoneutria boliviensis (Arachnida: Ctenidae)." The Journal of Arachnology 48, no. 1: 43-48.

Journal article
Published: 18 November 2019 in Biological Journal of the Linnean Society
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Morphological differences between the sexes are a common feature in many groups of animals and can have important ecological implications for courtship, mating, access to prey and, in some cases, intersex niche partitioning. In this study, we evaluated the role of sexual dimorphism in the performance of the two structures that mediate the ability to access prey, the pinchers or chelae and the venomous stinger, in two species of scorpions with contrasting morphologies: Chactas sp., which has marked sexual dimorphism in the chelae, and Centruroides sp., which does not have such marked dimorphism in the chelae. We evaluated aspects such as chela pinch force, toxicity to prey (LD50) and the volume of venom in males and females of each species. We found significant differences between males and females of Chactas sp. in the chela pinch force, volume of venom and LD50. In contrast, for Centruroides sp., no differences between males and females were found in any of these traits. We discuss several potential selective regimes that could account for the pattern observed.

ACS Style

Julio César González-Gómez; Juan Carlos Valenzuela-Rojas; Luis Fernando García; Lida Marcela Franco Pérez; Giovany Guevara; Sandra Buitrago; Allison Cubillos; Arie Van Der Meijden. Sexual dimorphism in the biomechanical and toxicological performance in prey incapacitation of two morphologically distinct scorpion species (Chactas sp. and Centruroides sp.). Biological Journal of the Linnean Society 2019, 1 .

AMA Style

Julio César González-Gómez, Juan Carlos Valenzuela-Rojas, Luis Fernando García, Lida Marcela Franco Pérez, Giovany Guevara, Sandra Buitrago, Allison Cubillos, Arie Van Der Meijden. Sexual dimorphism in the biomechanical and toxicological performance in prey incapacitation of two morphologically distinct scorpion species (Chactas sp. and Centruroides sp.). Biological Journal of the Linnean Society. 2019; ():1.

Chicago/Turabian Style

Julio César González-Gómez; Juan Carlos Valenzuela-Rojas; Luis Fernando García; Lida Marcela Franco Pérez; Giovany Guevara; Sandra Buitrago; Allison Cubillos; Arie Van Der Meijden. 2019. "Sexual dimorphism in the biomechanical and toxicological performance in prey incapacitation of two morphologically distinct scorpion species (Chactas sp. and Centruroides sp.)." Biological Journal of the Linnean Society , no. : 1.

Journal article
Published: 27 October 2019 in Toxins
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Spiders rely on venom to catch prey and few species are even capable of capturing vertebrates. The majority of spiders are generalist predators, possessing complex venom, in which different toxins seem to target different types of prey. In this study, we focused on the trophic ecology and venom toxicity of Phoneutria boliviensis F. O. Pickard-Cambridge, 1897, a Central American spider of medical importance. We tested the hypothesis that its venom is adapted to catch vertebrate prey by studying its trophic ecology and venom toxicity against selected vertebrate and invertebrate prey. We compared both trophic ecology (based on acceptance experiments) and toxicity (based on bioassays) among sexes of this species. We found that P. boliviensis accepted geckos, spiders, and cockroaches as prey, but rejected frogs. There was no difference in acceptance between males and females. The venom of P. boliviensis was far more efficient against vertebrate (geckos) than invertebrate (spiders) prey in both immobilization time and LD50. Surprisingly, venom of males was more efficient than that of females. Our results suggest that P. boliviensis has adapted its venom to catch vertebrates, which may explain its toxicity to humans.

ACS Style

Juan Carlos Valenzuela-Rojas; Julio César González-Gómez; Arie Van Der Meijden; Juan Nicolás Cortés; Giovany Guevara; Lida Marcela Franco; Stano Pekár; Luis Fernando García. Prey and Venom Efficacy of Male and Female Wandering Spider, Phoneutria boliviensis (Araneae: Ctenidae). Toxins 2019, 11, 622 .

AMA Style

Juan Carlos Valenzuela-Rojas, Julio César González-Gómez, Arie Van Der Meijden, Juan Nicolás Cortés, Giovany Guevara, Lida Marcela Franco, Stano Pekár, Luis Fernando García. Prey and Venom Efficacy of Male and Female Wandering Spider, Phoneutria boliviensis (Araneae: Ctenidae). Toxins. 2019; 11 (11):622.

Chicago/Turabian Style

Juan Carlos Valenzuela-Rojas; Julio César González-Gómez; Arie Van Der Meijden; Juan Nicolás Cortés; Giovany Guevara; Lida Marcela Franco; Stano Pekár; Luis Fernando García. 2019. "Prey and Venom Efficacy of Male and Female Wandering Spider, Phoneutria boliviensis (Araneae: Ctenidae)." Toxins 11, no. 11: 622.

Journal article
Published: 22 March 2017 in Zootaxa
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We describe a new scorpion species in the troglomorphic genus Troglotayosicus Lourenço, 1981 from Colombia. Troglotayosicus meijdeni sp. nov. inhabits the forest leaf litter at Rivera municipality, on the western slope of the Eastern Andes. The male of the new species remains unknown; however, this species can be distinguished from other species in the genus by the female (and juvenile) morphology. The type locality of T. meijdeni sp. nov. represents the northernmost known record for a population of Troglotayosicus, further extending the known limits of distribution of this genus, and shedding more light on the distributional range of this group of scorpions in northwestern South America. With this description, the number of known species of Troglotayosicus is raised to four; three of them are endogean species living in forested areas in the Andean region of Colombia, whereas one is a hypogean species from a cave in Ecuadorian Amazonia.

ACS Style

Ricardo Botero-Trujillo; Julio César González Gómez; Juan Carlos Valenzuela-Rojas; Luis Garcia. A new species in the troglomorphic scorpion genus Troglotayosicus from Colombia, representing the northernmost known record for the genus (Scorpiones, Troglotayosicidae). Zootaxa 2017, 4244, 568 -582.

AMA Style

Ricardo Botero-Trujillo, Julio César González Gómez, Juan Carlos Valenzuela-Rojas, Luis Garcia. A new species in the troglomorphic scorpion genus Troglotayosicus from Colombia, representing the northernmost known record for the genus (Scorpiones, Troglotayosicidae). Zootaxa. 2017; 4244 (4):568-582.

Chicago/Turabian Style

Ricardo Botero-Trujillo; Julio César González Gómez; Juan Carlos Valenzuela-Rojas; Luis Garcia. 2017. "A new species in the troglomorphic scorpion genus Troglotayosicus from Colombia, representing the northernmost known record for the genus (Scorpiones, Troglotayosicidae)." Zootaxa 4244, no. 4: 568-582.

Short communication
Published: 31 August 2016 in Insectes Sociaux
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Prey capture is a determinant aspect in arachnid sociality, since cooperative hunting allows the individuals access to very large prey. Although this behavior has been extensively studied in some spiders, the knowledge about some minor groups such as pseudoscorpions is still scarce. The aim of this study was to analyze diet composition, prey selectivity and prey size in Colombian populations of the social pseudoscorpion Paratemnoides nidificator. We collected prey captured by 112 colonies of P. nidificator as well as their potential prey. We found that hymenopterans (Formicidae) were the most consumed prey, while other items found in the diet included dipterans, embiopterans, hemipterans, mantids, neuropterans and spiders. When comparing prey composition, we found a low similarity between actual and potential prey. Paratemnoides nidificator showed a positive selectivity towards ant species which lacked strong defensive mechanisms, while avoiding potentially dangerous species which possess stingers or behaved aggressively. When evaluating size, we found that P. nidificator is able to prey on arthropods up to eight times larger than itself. These results suggest that by hunting in groups, P. nidificator is able to capture not only larger prey, but also prey which could be potentially dangerous for solitary individuals such as some ant species.

ACS Style

Luis Garcia; Julio César González Gómez; Juan Carlos Valenzuela-Rojas; E. Tizo-Pedroso; Mariangeles Lacava. Diet composition and prey selectivity of Colombian populations of a social pseudoscorpion. Insectes Sociaux 2016, 63, 635 -640.

AMA Style

Luis Garcia, Julio César González Gómez, Juan Carlos Valenzuela-Rojas, E. Tizo-Pedroso, Mariangeles Lacava. Diet composition and prey selectivity of Colombian populations of a social pseudoscorpion. Insectes Sociaux. 2016; 63 (4):635-640.

Chicago/Turabian Style

Luis Garcia; Julio César González Gómez; Juan Carlos Valenzuela-Rojas; E. Tizo-Pedroso; Mariangeles Lacava. 2016. "Diet composition and prey selectivity of Colombian populations of a social pseudoscorpion." Insectes Sociaux 63, no. 4: 635-640.

Journal article
Published: 01 October 2015 in Ethology Ecology & Evolution
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ACS Style

Mariangeles Lacava; Julio César González Gómez; Juan Carlos Valenzuela-Rojas; C. Moncayo; L. Cardozo; Everton Tizo-Pedroso; L.F. García. New cases of social parasitism among pseudoscorpions from Colombian populations. Ethology Ecology & Evolution 2015, 28, 452 -461.

AMA Style

Mariangeles Lacava, Julio César González Gómez, Juan Carlos Valenzuela-Rojas, C. Moncayo, L. Cardozo, Everton Tizo-Pedroso, L.F. García. New cases of social parasitism among pseudoscorpions from Colombian populations. Ethology Ecology & Evolution. 2015; 28 (4):452-461.

Chicago/Turabian Style

Mariangeles Lacava; Julio César González Gómez; Juan Carlos Valenzuela-Rojas; C. Moncayo; L. Cardozo; Everton Tizo-Pedroso; L.F. García. 2015. "New cases of social parasitism among pseudoscorpions from Colombian populations." Ethology Ecology & Evolution 28, no. 4: 452-461.