23 November, 2009

A new species of Compsobuthus from Mali

Wilson Lourenco has recently described a new species of Compsobuthus from Mali.

The Compsobuthus (Scorpiones, Buthidae) population previously recorded from Mali, and successively identified by Vachon as Compsobuthus acutecarinatus (Simon) and Compsobuthus werneri (Birula) is now confirmed as a new species from Western Africa.

Lourenco WR. A new species of Compsobuthus Vachon, 1949 from Mali (Scorpiones, Buthidae). Acta Biológica Paranaense. 2009;38(1-2):1-8. [Free fultext]

Family Buthidae

20 November, 2009

Reproductive traits in Paruroctonus boreus

James Barron and Amy L. Weidlich have recently published a research note on reproduction in the Northen Scorpion, Paruroctonus boreus (Vaejovidae), which is one of the most widespread species in North America (and also the most northern species, ranging into southern Canada).

Despite its large geographic range, little is known about reproductive traits in the northern scorpion (Paruroctonus boreus). We analyzed reproductive traits for 36 females from a population near Billings, Montana. All data were collected within a single year. Litter size, offspring mass, total litter mass (TLM), and relative litter mass (RLM) were within the ranges of values reported for other species in the Vaejovidae. Female size (length or mass) was not correlated with any reproductive trait. Litter size and offspring mass were each positively correlated with RLM, suggesting that females investing relatively larger amounts of energy in reproduction increase both size and number of offspring. Finally, the within-litter coefficient of variation in offspring mass was negatively correlated with RLM, TLM, and mean offspring mass, suggesting that females investing more energy in reproduction produce more-uniformly sized offspring, an observation that appears common in scorpions.

Barron JN, Weidlich AL. Reproductive traits in the northern scorpion (Paruroctonus boreus). West North Am Naturalist. 2009 Sep;69(3):399-402. [Free fultext]

Family Vaejovidae

18 November, 2009

Inter- and intrapopulational genetic variability of Tityus serrulatus

Ronaldo Carvalho Scholte and co-workers have recently published a study on the genetic variability of different populations of Tityus serrulatus (Buthidae) in Brazil. T. serrulatus is a parthenogentic species of medical importance that has an increasing distribution in Brazil, and knowledge of its genetics and reproductive mechanisms is of great interest.

In Brazil, there are near 20 genera and almost 120 species of scorpions of which 95% reproduce sexually. Parthenogenetic reproduction, however,may also take place. To gain insight into useful molecularmarkers in parthenogenetic scorpion species, we studied DNA polymorphism using two molecular approaches: simple sequence repeat anchored polymerase chain reaction (SSR-PCR) and sequencing of the cytochrome C oxidase subunit I of the mitochondrial genome,mtDNA(COXI), of Tityus serrulatus. Three different groups were used: group 1, composed of 1 female and 14 descendants; group 2 with 1 female and 17 descendants, both from the city of Uberlândia, State of Minas Gerais (MG), Brazil, and the third group that consisted of three adult scorpions from the city of Belo Horizonte, MG.

The profiles generated by SSR-PCR were identical for all specimens, while partial sequencing of COXI showed the presence of SNPs. After aligning COXI contigs, one of the groups presented 18 SNPs and the second 8 SNPs. The two groups were differentiated by two diagnostic SNPs. We did not find evidence of mitochondrial recombination.

The results are in agreement with the parthenogenetic mode of reproduction of this species and sequencing of the COXI gene enabled the separation of scorpions groups.

Scholte RGC, Caldeira RL, Simoes MCM, Stutz WH, Silva LL, Carvalho OD, et al. Inter- and intrapopulational genetic variability of Tityus serrulatus (Scorpiones, Buthidae). Acta Trop. 2009 Nov;112(2):97-100. [Subscription required for fulltext]

Family buthidae

17 November, 2009

Chemical scorpion control in Brazil

Scorpions constitutes a public health problem in many parts of Brazil. This is specially a problem in many urban areas where the effects of human activity and expansion into the scorpions natural habitats have increased the number of human-scorpion contacts. Some species has also adapted well to urban environments.

Chemical control of scorpions by the use of insecticides is common in Brazil, in addition to community involvement and education. The effects of insecticides against scorpions are controversial and not documented properly. Some insecticides actually may have an irritant effect on scorpions by increasing their activity and aggression, and thereby causing an increased risk of sting incidents.

Cleide Maria Ribeiro de Albuquerque and co-workers have now published a very interesting study on the effects of chemical control on the medical important species Tityus stigimurus (Buthidae) and the importance of community knowledge of scorpionism.

In this study, the events following application of the insecticide Demand 2.5 concentrated solution (CS) in the field, to control Tityus stigmurus, were investigated. Data on attitudes and practices relating to scorpionism were collected using a questionnaire. During the months of May to July 2005, 69 premises were monitored on different days following insecticide treatment, focusing on scorpion frequency and mortality. According to the results, 42% of the premises showed scorpion incidence, with an average of three specimens per house. The highest incidence was recorded during the first week following the treatment. Only 7% of the specimens were found dead. Most (72%) of the population showed knowledge about prevention and control measures. Despite this, 100% of the premises presented breeding sites, mainly in debris (79.7%). These results indicate that the scorpion control method used by health agents during this investigation was not efficient, and the results suggest that the method may have had a dispersive effect on these animals.

De Albuquerque CMR, Barbosa MO, Iannuzzi L. Tityus stigmurus (Thorell, 1876) (Scorpiones; Buthidae): Response to chemical control and understanding of scorpionism among the population. Rev Soc Bras Med Trop. 2009;42(3):255-9. [Free fultext]

Family Buthidae

11 November, 2009

Two Euscorpius species coexisting in the same habitat in Italy

Scorpions found within the same area will often choose different habitats and behavioral strategies to avoid competition. Marco Colombo has now reported some interesting observations of Euscorpius italicus and E. tergestinus found in the same area and in the same habitat in Italy. The observations and the existence of sympatry (organisims living in the same geographical territory/geographical area) and syntopy (organisms living in the same habitat(s) within the geographical distribution of the organisms) in scorpions are discussed.

The author found syntopic specimens of Euscorpius italicus and E. tergestinus inside and nearby an abandoned fortress in Verona Province, Veneto, Italy. This discovery highlights a possibility of coexistence of congeneric species not only in the same territory, as already observed, but also in the same habitat and microhabitat, bringing some interesting questions about interspecific competition within the genus Euscorpius.

Colombo M. On two syntopic species of Euscorpius Thorell, 1876 (Scorpiones: Euscorpiidae) in and nearby San Marco fortress (Veneto, Italy): a prelimnary investigation. Euscorpius. 2009(87):1-14. [Free fulltext]

Family Euscorpiidae

10 November, 2009

The genus Vachoniochactas and the description of a new species

Wilson Lourenco and Bernard Duhem are discussing the genus Vachoniochactas in the Guyana region of South America in a forthcoming paper in the journal Comptes Rendus Biologies. They also describe a new species in the genus in the a border area of Brazil, Gyuana and Venezuela.

Vanchoniochactas roraima Lourenco & Duhem, 2009 (Chactidae)

A new species, Vachoniochactas roraima sp. n. (Chactidae) is described from Mount Roraima, a site located on the borders of Brazil, Guyana and Venezuela. The description of the new species brings further evidence to the biogeographic pattern of distribution presented by the genus Vachoniochactas, as an endemic element to the Tepuys formations of South America.

Lourenço WR, Duhem B. The genus Vachoniochactas González-Sponga (Scorpiones, Chactidae), a model of relictual distribution in past refugia of the Guayana region of South America. Comptes Rendus Biologies. 2009 (In Press). DOI:10.1016/j.crvi.2009.09.006. [Subscription required for fulltext]

Family Chactidae

03 November, 2009

A new Vaejovis from Arizona, USA

Richard Ayrey has described a new species of Vaejovis (Vaejovidae) from the Santa Catalina Mountains in Arizona (USA).

A new scorpion species, Vaejovis deboerae, sp. nov., is described and placed in the “mexicanus” group of the genus Vaejovis. They are small light yellowish brown scorpions found in the Santa Catalina Mountains, one of the sky islands of southern Arizona. They are closely related to V. vorhiesi Stahnke. The original description of V. vorhiesi Stahnke, 1940 and redescription (Graham, 2007), state that they are found in the Huachuca and Santa Catalina Mountains of southern Arizona. No specimens from the Santa Catalina Mountains were included in the redescription based on the lack of adequate material. The redescription stated “…the Santa Catalina Mountains scorpions definitely warrant further study if specimens become available.” This description of a new species is based on ample specimens now being available.

Ayrey RF. Sky Island Vaejovis: A new species (Scorpiones: Vaejovidae). Euscorpius. 2009; (86):1-12. [Free fulltext]

Family Vaejovidae