21 September, 2018

Three new species of Chaerilus from Malaysia and Thailand

Frantisek Kovarik and co-workers have recently published a new article describing three new species of Chaerilus Simon, 1877 (Chaerilidae) from Malaysia and Thailand.

Chaerilus majkusi Kovarik, Lowe & Stahlavsky, 2018 (Malaysia)

Chaerilus neradorum Kovarik, Lowe & Stahlavsky, 2018 (Thailand)

Chaerilus stockmannorumi Kovarik, Lowe & Stahlavsky, 2018 (Thailand)

The articles have pictures of live speciemens of the new species.

Chaerilus majkusi sp. n. from Malaysia (Tioman Island), C. neradorum sp. n. and C. stockmannorum sp. n. from Thailand are described and fully illustrated with color photographs of live and preserved specimens, as well as of their habitat. They are compared to the species C. cimrmani Kovařík, 2012, C. sejnai Kovařík, 2005, and C. tichyi Kovařík, 2000, which we also illustrate with color photographs of live unpublished specimens. Hemispermatophores of C. cimrmani, C. majkusi sp .n., C. stockmannorum sp. n., and C. tichyi are illustrated and compared, and we also describe the karyotypes of C. cimrmani, C. majkusi sp. n., C. neradorum sp. n., C. stockmannorum sp. n., C. sejnai and C. tichyi. The diploid numbers of chromosomes range from 76 to 186 and the karyotypes show distinct inter-specific variability among analyzed species. C. stockmannorum sp. n. (2n=186) possesses the highest number of chromosomes within the order Scorpiones and the class Arachnida.

Kovarik F, Lowe G, Stahlavsky F. Three New Chaerilus from Malaysia (Tioman Island) and Thailand (Scorpiones: Chaerilidae), with a Review of C. cimrmani, C. sejnai, and C. tichyi. Euscorpius. (268):1-27. [Open Access]

Family Chaerilidae

13 September, 2018

A review on the epidemiology and distribution of medical important scorpions in North America

It is well known that North America and especially Mexico is a hotspot for medical important scorpions. Canada has no dangerous species, while USA has only one (Centruroides sculpturatus Ewing, 1928). Mexico, on the other side, has several species that have great consequences for the public health.

Gonzalez-Santillan & Possani have recently published a review summing up the current knowledge on the distribution and epidemiology of the medical important scorpions of North America. 21 species and one subspecies, all in the genus Centruroides, are identified as medical important, and their distribution is given. The different aspects of scorpionism in North America is also discussed.

Scorpionism is a severe threat to public health in North America. Historically, few species of Centruroides have been considered to be the offending taxa, but we know now that their diversity is greater and our knowledge incomplete. Current distribution maps are inadequate for some species. Epidemiologic studies are sporadic and local, and a complete synthesis for North America is missing. We analyze historical and recent knowledge about the identity, distribution and epidemiology of species of medical importance in North America. PubMed, Google Scholar, the National Collection of Arachnids, and results of recent field work were consulted in the preparation of our analysis. We recognized 21 species and one subspecies of medically important scorpions in need of precise geographical delimitation. All these species are found in Mexico, which is clearly a hotspot for scorpionism. Although mortality has been steadily decreasing, deaths still occur, and morbidity remains high. Mortality is most common at age classes of 0–10 years and>50. Morbidity is highest in age class 15–50 years, including the most economically active segment of the population. The season of the highest incidence of scorpion sting peaks between spring and summer but there appears to be a second, lower peak at the end of the summer. Although the systematics of the genus Centruroides has advanced considerably, our knowledge of its diversity remains fragmentary. There is a disconnection between the actual distribution of the scorpions and the incidence maps constructed from scorpion sting records. Despite a historically robust knowledge of the distribution of wellknown species, most recently described species are known from only a few localities. Some of the epidemiological parameters are consistent among studies reported herein.

Gonzalez-Santillan E, Possani LD. North American scorpion species of public health importance with a reappraisal of historical epidemiology. Acta Trop. 2018;187:264-74. [Subscription required for full text]