21 June, 2018

Scorpion fear

Arachnophobia actually means fear for arachnids, but in most cases this term is used for spider fear or phobia. There haven't been many studies investigating the presence of fear of scorpions or other arachnids. In a recent study, Richard Vetter and co-workers studied the presence of scorpion fear compared to fear of spiders in 850 university students from five different campuses in USA.

The results were surprising. The researchers expected expected a higher fear for spiders than for scorpions, but they found the opposite - a higher fear for scorpions that for spiders. The authors provide to explanation for this result and recommend that more research should be done into this interesting topic.

No abstract available.

Vetter RS, Draney ML, Brown CA, Trumble JT, Gouge DH, Hinkle NC, et al. Spider Fear Versus Scorpion Fear in Undergraduate Students at Five American Universities. American Entomologist. 2018;64(2):79-82. [Subscription required for full text]

08 June, 2018

A desert scorpion can smell its enemies

Avoid being eaten or killed is one of the fundamental drives in all animals and an impressive range of anti-predator tactics have been described. Scorpions have their powerful claws and a venomous sting, but other tools are also available.

Zia Nisani and co-workers have now published a very interesting article showing that the desert scorpion Paruroctonus marksi (Haradon, 1984) (Vaejovidae) can actually smell the proximity of a potential predator (in this case the much larger scorpion Hadrurus arizonensis (Ewing, 1928) (Caraboctonidae)) and then avoid approaching it. This is the first evidence of airborne chemoreception as an anti-predator strategy in scorpions.

One of the experiments in this study point to a special constellation array of sensilla (or a yet unidentified structure) on the pedipalps as the "sense organ" used to detect the odors of predators.

Chemically induced predator avoidance behaviors exist in many arthropods. In this paper, we examined the behavioral responses of the desert scorpion, Paruroctonus marksi (Haradon, 1984), to airborne chemical cues from a natural predator, the larger scorpion Hadrurus arizonensis (Ewing, 1928). We used a Y-shaped, dual-choice olfactometer to test for avoidance behavior in the presence of a known predator, H. arizonensis. Prior to this study there has been little research done on chemically induced predator avoidance behaviors in scorpions. The results of this study suggest that P. marksi is capable of detecting a predator’s airborne cues, though the nature and identity of these cues remain unknown, and it appears that the constellation array of the fixed finger does function in detecting these cues. We also discuss the importance of adaptive predator avoidance behaviors.

Nisani Z, Honaker A, Jenne V, Loya F, Moon H. Evidence of airborne chemoreception in the scorpion Paruroctonus marksi (Scorpiones: Vaejovidae). Journal of Arachnology. 2018;46:40-4. [Open Access]

Thanks to Matt Simon for informing me about this article!

07 June, 2018

An interesting study on prey capture behavior in Bothriurus bonariensis

I'm always happy to read new studies on scorpion behavior. There are not that many of them, and my background is in animal behavior and I did my master thesis on sting use and prey capture behavior in two species of Parabuthus Pocock, 1890.

Yuri Simone and co-workers have now published an interesting study on prey capture behavior in female Bothriurus bonariensis (C.L. Koch, 1842) (Bothriuridae). The study describes the consumption, subduing time, feeding strategy and stinger use against different types of prey from the scorpions habitat (the prey differed in size, morphology and/or defense capabilities).

The main conclusion is that Bothriurus bonariensis is able to use different predatory strategies which might allow it to include prey with diverse defensive strategies in its diet. I refer to the abstract and the articles for further details on the results and discussion.

Scorpions are dominant predators in some environments. Nevertheless, most studies of predatory behavior in scorpions have focused on diet composition whereas some other relevant aspects, such as predatory strategy, have been poorly explored. Herein we evaluate the prey acceptance and predatory strategy of the scorpion Bothriurus bonariensis against sympatric prey with different defenses. As prey, we selected earwigs (Forficula cf. auricularia) which use pincer-like defensive appendages, hard-bodied isopods (Armadillium vulgare) known for their conglobation defensive strategy, soft bodied isopods (Porcellio cf. scaber), which secrete noxious substances as defense mechanisms, cockroaches with limited defensive mechanisms (Blatta cf. orientalis.) and spiders (Lycosa cf. poliostoma) which possess venomous fangs. Prey were offered to 21 adults of B. bonariensis in random order until all prey had been offered to all scorpions. Prey consumption and the number of attempts needed for capture were recorded. We also evaluated the effect of sting use on immobilization time as well as the prey capture strategies on the most consumed prey. We found that despite using a similar number of attempts for capturing all prey, spiders and armadillid isopods were less consumed than other prey. Immobilization times were longer for earwigs than for armadillid isopods and cockroaches. Scorpions used alternative predatory strategies against these aforementioned prey, although the stinger was used against all of them. These results show that scorpions are able to use different predatory strategies which might allow them to include prey with diverse defensive strategies in their diet.

Simone Y, Garcia LF, Lacava M, van der Meijden A, Viera C. Predatory Versatility in Females of the Scorpion Bothriurus bonariensis (Scorpiones: Bothriuridae): Overcoming Prey with Different Defensive Mechanisms. Journal of Insect Behavior. 2018;First Online 01 June 2018. [Subscription required for full text]

06 June, 2018

The scorpion fauna of French Guiana and description of four new species

Eric Ythier has just published a synopsis of the scorpion fauna of French Guiana. In the paper, four new species are described.

Ananteris kalina Ythier, 2018

Auyantepuia aluku Ythier, 2018*
Auyantepuia aurum Ythier, 2018*
Hadrurochactas cristinae Ythier, 2018

*The genus Auyantepuia was synonymized with other genera by Soleglad & Fet. 2005. Lourenço & Qi (2007) and Eric Ythier have chosen not to accept this synonymization, and described the new species in Auyantepuia, but no justifying the revalidation of the genus have been provided. The taxonomy of The Scorpion Files follows Soleglad & Fet (2005), but it is impossible for me to know where to put the new species. I have chosen to reinstate Auyantepuia in The Scorpion Files for this species until a new revision on the family Chactidae is published. Auyantepuia is not counted in the number of genera for the family, but the species are included.

The articles has habitat description and pictures. The species list for French Guiana is updated and an identification key for the 30 species in the country is provided.

A synopsis is provided for all scorpion species collected in French Guiana, including thorough diagnoses and additional distributional records for each documented species. Four new species are also described in this paper (one Ananteris from northeastern Guiana, two Auyantepuia from central and northeastern Guiana and one Hadrurochactas from western Guiana), raising the total number of species described from French Guiana to 30. Most of the species are illustrated, geographical distribution maps are presented, and a key to the species is proposed.

Ythier E. A synopsis of the scorpion fauna of French Guiana, with description of four new species. ZooKeys. 2018(764):27-90. [Open Access]

Thanks to Eric Ythier for sending me his article!

Family Buthidae
Family Chactidae

05 June, 2018

A new Vaejovis from Arizona, USA

Richard Ayrey has recently described a new species of Vaejovis C. L. Koch, 1836 (Vaejovidae) from the Patagonia Mountains, Southern Arizona.

Vaejovis patagonia Ayrey, 2018

A new scorpion species, Vaejovis patagonia sp. nov. is described and placed in the “vorhiesi” group. This small, dark brown species is found near Patagonia, Arizona. It is geographically closest to V. troupi Ayrey & Soleglad, V. grahami Ayrey & Soleglad and V. vorhiesi Stahnke. Those three species are found in a triangle surrounding the Patagonia Mountains, the locality of Vaejovis patagonia. The pedipalp fixed finger has 5 ID denticles and the movable finger has 6, like most, but not all, of the other southern Arizona Vaejovis. Carapace of female is shorter than metasomal segment V.

Ayrey RF. A New Species of Vaejovis from the Patagonia Mountains, Southern Arizona (Scorpiones: Vaejovidae). Euscorpius. 2018(262):1-12. [Open Access]

Family Vaejovidae

31 May, 2018

A new scorpion book has been published in Dutch

Dutch scorpion enthusiast Jeroen Kooijman has recently authored a scorpion book written in Dutch. Kooijman is an experienced scorpion enthusiast that has been keeping and breeding scorpions for more than 20 years. He has also given lectures, courses and more about scorpions in The Netherlands for many years. This is the first scorpion book in Dutch, complimenting the books already available in English and German.

I haven't seen the book yet, but based on my knowledge of Jeroen and the Dutch scorpion community I'm quite sure that this will be an important information source about scorpions in captivity and in general.

The book is published by the Dutch Scorpion Society and can be ordered from info@schorpioen.org.

29 May, 2018

A new species of Vaejovis from Sonora, Mexico

Diego A. Barrales-Alcalá and co-workers have recently published an article describing a new species of Vaejovis C. L. Koch, 1836 (Vaejovidae) from Sonora, Mexico.

Vaejovis islaserrano Barrales-Alcalá, Francke, Van Devender & Contreras-Félix, 2018

Vaejovis islaserrano sp. n. is described from the Sierras Elenita and La Mariquita, Municipio de Cananea, Sonora, Mexico. This species belongs to the “vorhiesi” group of the genus Vaejovis and inhabits pine-oak forests in northern Mexico. This species is compared to its most similar species. This new species presents an interesting morphological difference from the rest of the species in the species-group: the absence of a subaculear tubercle or spine.

Barrales-Alcalá DA, Francke OF, Van Devender TR, Contreras-Félix GA. A new Sky Island species of Vaejovis C. L. Koch, 1836 from Sonora, Mexico (Scorpiones, Vaejovidae). ZooKeys. 2018(760):37-53. [Open Access]

Thanks to Oscar Francke for sending me this article!

Family Vaejovidae