06 July, 2018

A surprise from Crete - A second Mesobuthus species discovered

Mesobuthus gibbosus (Brulli, 1832) (Buthidae) has been well known from the Greek island Crete, but very recently Eric Ythier has published an article describing a second species from the Lassithi Plateau in Crete.

Mesobuthus gallianoi Ythier, 2018

A new species of scorpion belonging to the genus Mesobuthus Vachon, 1950 (family Buthidae C. L. Koch, 1837) is described on the basis of one specimen collected on the Lassithi Plateau, in Crete (Greece). The new species is characterised by a high number of rows of granules on mobile (14 rows) and fixed fingers (13 rows), lateromedian carinae vestigial on metasomal segment IV, an interspace between median carina and each paramedian carina 1.2-1.7 times as wide as the paramedian carina on tergites IV-VI, and a rather high pectinal tooth count with 26-27 teeth in female. This is the second species of the genus Mesobuthus reported from Crete.

Ythier E. A new species of Mesobuthus Vachon, 1950 (Scorpiones: Buthidae) from Crete (Greece). Revista Iberica de Arachnologia. 2018(32):87-92.

Thanks to Eric for sending me his new article!

Family Buthidae

04 July, 2018

Environmental variation and seasonal changes as determinants of the spatial distribution of scorpion in Neotropical forests

Andre Lira and co-workers have recently published a new article on the population dynamics of scorpions in Neotropical forests. They found 12 species in the study area and collected data on microhabitat preferences, foraging activity, spatial distribution, seasonal changes effects etc.

Their main conclusion is that spatiotemporal resource partitioning and refuge sharing are important drivers of the population dynamics and spatial distribution of scorpion species in Neotropical forests. See abstract or article for more details.

Habitat selection and seasonal changes are key drivers of the population dynamics of many species. We analyzed how the environmental structure influences species establishment in an area by comparing microhabitat preference and functional richness of scorpions (Arachnida: Scorpiones) in wet (Atlantic forest) and semiarid (Caatinga) areas. Variations in superficial foraging activity and microhabitat colonization during dry and rainy seasons were evaluated as an indication of the climatic impact on population dynamics. We collected twelve scorpion species using ultraviolet light lamps. We found that differential patterns in spatial distribution were independent of forest type, and we provide evidence for partial niche partitioning among scorpion species based on age class and climatic conditions. Foraging activity was also seasonally influenced. Functional richness was higher in wet forests than in dry forests, whereas taxonomical richness exhibited an opposite pattern. We conclude that spatiotemporal resource partitioning and refuge sharing are important drivers of the population dynamics and spatial distribution of scorpion species in Neotropical forests.

Lira A, DeSouza A, Albuquerque C. Environmental variation and seasonal changes as determinants of the spatial distribution of scorpion (Arachnida: Scorpiones) in Neotropical forests. Can J Zool. 2018;In Press. [Subscription required for full text]

Thanks to Andre Lira for sending me their article!

03 July, 2018

The response to edge effects in two sympatric litter-dwelling scorpions in a Brazilian Atlantic forest

The edge effects in ecology are changes in population or community structures that occur at the boundary of two or more habitats (Wikipedia). Welton Dionisio-da-Silva and co-workers have recently published a study on how the abundance of two sympatric scorpion species (Tityus pusillus Pocock, 1893 and Ananteris mauryi Lourenço, 1982 (Buthidae)) and their potential prey varied as a function of microhabitat changes from edge to interior forest habitats.

The results show a different response to the edge effects in the two species, A. mauryi being not so much influenced by edge effects as T. pusillus. Se abstract and article for more details.

Edge effects have drastically affected species living in tropical forests. However, understanding how species respond to edge effects remains a challenge, owing to the many factors involved and different responses of each species thereto. Here, we analyzed how the abundance of two sympatric scorpion species (Tityus pusillus and Ananteris mauryi) and their potential prey varied as a function of microhabitat changes (litter depth, dry mass, and leaf shape) from edge to interior forest habitats. We further analyzed the contribution of potential prey to scorpion abundance and reproductive periods. Data were collected monthly at three 300-m² transects/site at distances of 10, 100, and 200 m from the forest edge in a fragment of the Atlantic forest in northeastern Brazil, between April 2016 and March 2017. Scorpions responded differentially to edge effects, with A. mauryi abundance being similar along the edge-interior gradient, whereas T. pusillus had a higher abundance in the interior. As T. pusillus inhabit the top layer of the leaf litter, this species will possibly be more influenced by edge effects. In contrast, being a humicolous scorpion and inhabiting the bottom layers of leaf litter, A. mauryi would not be influenced by edge effects as much as T. pusillus. The reproductive period also was distinct between the two species, with T. pusillus reproducing in the dry season and A. mauryi in the rainy season. The oscillation in the abundance of different groups of prey at different periods maintained the overall prey abundance at a relatively constant level throughout the year, mitigating the effects of prey availability on the abundance and reproductive period of the scorpions. These results suggest that microhabitat exploitation is a key factor to sustain litterdwelling scorpions in disturbed forest remnants and that T. pusillus can be an ecological indicator of edge effects.

Dionisio-da-Silva W, de Araujo Lira AF, de Albuquerque CMR. Distinct edge effects and reproductive periods of sympatric litter-dwelling scorpions (Arachnida: Scorpiones) in a Brazilian Atlantic forest. Zoology. 2018;129:17-24. [NB! Open Access until 17.08.18, then subscription required for access]

Thanks to Welton Dionisio da Silva and Andre Lira for informing me about their article!

Family Buthidae

02 July, 2018

A revision of the cryptic genus Microbuthus and the description of a new species

Graeme Lowe and co-workers have recently published a review of the cryptic genus Microbuthus Kraepelin, 1898 (Buthidae) from western and eastern coasts of North Africa and the southern coast of the Arabian Peninsula. A new species is also described.

Microbuthus satyrus Lowe, Kovarik, Stockmann & Stahlavsky, 2018 (Oman, Yemen)

The taxonomy of the genus Microbuthus is reviewed, and a new species from Oman and Yemen, M. satyrus sp. n., is described and fully illustrated with color photographs of live and preserved specimens, as well as of its habitat. It is compared to the closely similar species M. litoralis, which we also illustrate. Synonymy of the type species M. pusillus Kraepelin, 1898 with M. litoralis (Pavesi, 1885) is confirmed, and the species is recorded for the first time from Yemen. Hemispermatophores of M. satyrus sp. n., M. gardneri Lowe, 2010, and M. kristensenorum Lowe, 2010 are illustrated and compared, and we also describe the karyotypes of these three Microbuthus species. The number of chromosomes is the same in all analyzed species (2n=26).

Lowe G, Kovarik F, Stockmann M, Stahlavsky F. Review of Microbuthus with description of M. satyrus sp. n. (Scorpiones, Buthidae) from Oman and Yemen. Euscorpius. 2018(263):1-22. [Open Access]

Family Buthidae

27 June, 2018

A revision of three vaejovid genera and three new Thorellius species

Edmundo González-Santillán and Lorenzo Prendini have recently published a systematic review of the three North American genera Balsateres González-Santillán and Prendini, 2013, Kuarapu Francke and Ponce-Saavedra, 2010 and Thorellius Soleglad and Fet, 2008 (Vaejovidae). Three new species is described and one taxa is synonymized.

New species:

Thorellius tekuani Gonzalez-Santillan & Prendini, 2018 (Mexico)
Thorellius wixarika Gonzalez-Santillan & Prendini, 2018 (Mexico)
Thorellius yuyuawi Gonzalez-Santillan & Prendini, 2018 (Mexico)


Thorellius atrox (Hoffmann, 1931) is synonymized with Thorellius cristimanus (Pocock, 1898).

The article present new distributional data and an identification key for the genus Thorellius.

Four genera formed a monophyletic group, referred to as the Kochius clade, in the phylogeny of the North American vaejovid scorpion subfamily Syntropinae Kraepelin, 1905: Balsateres González-Santillán and Prendini, 2013; Kochius Soleglad and Fet, 2008; Kuarapu Francke and Ponce-Saavedra, 2010; and Thorellius Soleglad and Fet, 2008. In the present contribution, all except Kochius, treated elsewhere, are revised. The monotypic Balsateres and Kuarapu are redescribed. Thorellius cristimanus (Pocock, 1898) and Thorellius intrepidus (Thorell, 1876) are redescribed and their type localities discussed and clarified. Three new species of Thorellius are described: Thorellius tekuani; Thorellius wixarika; and Thorellius yuyuawi. Vaejovis intrepidus atrox Hoffmann, 1931, is newly synonymized with T. cristimanus based on examination of the type material. A key to identification of the species of Thorellius is presented, and new locality records and updated distribution maps provided for all species covered.

Gonzalez Santillan E, Prendini L. Systematic revision of the North American syntropine vaejovid scorpion genera Balsateres, Kuarapu, and Thorellius, with descriptions of three new species. Bulletin of the American Museum of Natural History. 2018(420):1-81. [Open Access]

Thanks to Edmundo González-Santillán for informing me about their article!

Family Vaejovidae

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!