First biochemical and behavioural analysis of the response of the scorpion Urophonius brachycentrus (Thorell: 1876) upon exposure to an organophosphate.

Scorpionism is an increasing public health problem in the world. Although no specific methodology or product is currently available for the control of those arachnids, the use of insecticides could be an effective tool. Chlorpyrifos is one of the insecticides used, but to date, whether scorpions recognise surfaces with that insecticide and how it affects their physiology and/or biochemistry is unknown. In the present study, we observed that scorpions recognise surfaces with 0.51 and 8.59 µg/cm2 of chlorpyrifos and avoid those areas. The 0.51 µg/cm2 concentration produced a decrease in acetylcholinesterase and an increase in catalase, superoxide dismutase and glutathione S-transferase, whereas the 8.59 µg/cm2 concentration evoked a decrease in acetylcholinesterase and an increase in catalase and glutathione S-transferase. Using the comet assay, we observed that the insecticide at 0.17, 0.51 and 8.59 µg/cm2 caused DNA damage. Finally, we found that the insecticide does not generate significant variations in glutathione peroxidase, glutathione reductase, the amount of protein or lipid peroxidation. The present results offer a comprehensive understanding of how scorpions respond, both at the biochemical and behavioural levels, when exposed to insecticides.

A plurality of morphological characters need not equate with phylogenetic accuracy: A rare genomic change refutes the placement of Solifugae and Pseudoscorpiones in Haplocnemata.

Recent advances in higher-level invertebrate phylogeny have leveraged shared features of genomic architecture to resolve contentious nodes across the tree of life. Yet, the interordinal relationships within Chelicerata have remained recalcitrant given competing topologies in recent molecular analyses. As such, relationships between topologically unstable orders remain supported primarily by morphological cladistic analyses. Solifugae, one such unstable chelicerate order, has long been thought to be the sister group of Pseudoscorpiones, forming the clade Haplocnemata, on the basis of eight putative morphological synapomorphies. The discovery, however, of a shared whole genome duplication placing Pseudoscorpiones in Arachnopulmonata provides the opportunity for a simple litmus test evaluating the validity of Haplocnemata. Here, we present the first developmental transcriptome of a solifuge (Titanopuga salinarum) and survey copy numbers of the homeobox genes for evidence of systemic duplication. We find that over 70% of the identified homeobox genes in T. salinarum are retained in a single copy, while representatives of the arachnopulmonates retain orthologs of those genes as two or more copies. Our results refute the placement of Solifugae in Haplocnemata. Subsequent reevaluation of putative interordinal morphological synapomorphies among chelicerates reveals a high incidence of homoplasy, reversals, and inaccurate coding within Haplocnemata and other small clades, as well as Arachnida more broadly, suggesting existing morphological character matrices are insufficient to resolve chelicerate phylogeny.

Neglected no longer: Phylogenomic resolution of higher-level relationships in Solifugae.

Advanced sequencing technologies have expedited resolution of higher-level arthropod relationships. Yet, dark branches persist, principally among groups occurring in cryptic habitats. Among chelicerates, Solifugae ("camel spiders") is the last order lacking a higher-level phylogeny and have thus been historically characterized as "neglected [arachnid] cousins". Though renowned for aggression, remarkable running speed, and xeric adaptation, inferring solifuge relationships has been hindered by inaccessibility of diagnostic morphological characters, whereas molecular investigations have been limited to one of 12 recognized families. Our phylogenomic dataset via capture of ultraconserved elements sampling all extant families recovered a well-resolved phylogeny, with two distinct groups of New World taxa nested within a broader Paleotropical radiation. Divergence times using fossil calibrations inferred that Solifugae radiated by the Permian, and most families diverged prior to the Paleogene-Cretaceous extinction, likely driven by continental breakup. We establish Boreosolifugae new suborder uniting five Laurasian families, and Australosolifugae new suborder uniting seven Gondwanan families using morphological and biogeographic signal.

Description of Bothriurus mistral n. sp., the highest-dwelling Bothriurus from the western Andes (Scorpiones, Bothriuridae), using multiple morphometric approaches.

We describe Bothriurus mistral n. sp. (Scorpiones, Bothriuridae) from the Chilean north-central Andes of the Coquimbo Region. This is the highest elevational discovery for Bothriurus in the western slopes of the Andes. This species was collected in the Estero Derecho Private Protected Area and Natural Sanctuary as part of the First National Biodiversity Inventory of Chile of the Integrated System for Monitoring and Evaluation of Native Forest Ecosystems (SIMEF). Bothriurus mistral n. sp. is closely related to Bothriurus coriaceus Pocock, 1893, from the lowlands of central Chile. This integrative research includes a combination of traditional morphometrics and geometric morphometric analyses to support the taxonomic delimitation of the species.

Behaviour, feeding and cytogenetic features of the wingless blood-sucking ectoparasite Cyanolicimex patagonicus (Heteroptera: Cimicidae).

Cyanolicimex (Haematosiphoninae) includes a single species, C. patagonicus, which is found in the largest known colony of its avian host Cyanoliseus patagonus (Psittacidae) located in Patagonia (Argentina). Relationships between Cyanolicimex and other genera of Haematosiphoninae are still unclear because this genus shares some characters with other South American genera and possesses some similarities with Hesperocimex from the Neoarctic region. The aim of the present study was to provide additional data of C. patagonicus so as to better understand its relationships with other South American species. We examined some biological features of C. patagonicus in the field and we performed a cytogenetic analysis. We observed in the field that C. patagonicus does not live inside the hollow nests of Cyanoliseus patagonus. The cytogenetic analysis showed that the male karyotype is 2n= 31= 28A+X1X2Y and revealed an achiasmate male meiosis and of the collochore type. Our results together with available cytogenetic data in other cimicids, allow proposing the possible chromosomal rearrangements involved in the chromosomal evolution of C. patagonicus and also contribute to better understand the evolutionary divergence at the chromosomal level within Haematosiphoninae. Based on the whole evidence, we propose to place in four groups the species of Haematosiphoninae cytogenetically hitherto studied.

Chileotrecha romero (Kraus, 1966) comb. nov. and Pseudocleobis patagonicus (Roewer, 1934) comb. nov. transferral from Mummuciidae to Ammotrechidae (Arachnida, Solifugae).

The solifuge species Mummucina romero Kraus, 1966, from Chile, and Mummucia patagonica Roewer, 1934, from Argentina, are here transferred from Mummuciidae Roewer, 1934 to Ammotrechidae Roewer, 1934. Chileotrecha romero (Kraus, 1966) comb. nov. and Pseudocleobis patagonicus (Roewer, 1934) comb. nov. are proposed. Comments on their morphology are made and previous distributional records are discussed. Pseudocleobis patagonicus is proposed as a nomen dubium. In addition, we confirm that female and immature specimens of the family Mummuciidae, just like males, can be reliably recognized based on features that had been suggested by Maury (1984).

A revision of the Neotropical genus Austrohahnia Mello-Leitão (Araneae, Hahniidae).

The Neotropical genus Austrohahnia Mello-Leitão, 1942 is revised, comprising four species from Argentina. The genus is here transferred to the subfamily Hahniinae Bertkau, 1878 from Cybaeolinae Lehtinen, 1967. Austrohahnia is diagnosed by a single synapomorphy, short setae ventrally on the abdomen, in immature as well as adult stages. The type species A. praestans Mello-Leitão, 1942 is redescribed. Austrohahnia catleyi new species is described and illustrated based both sexes from the alder forests of northwestern Argentina. Austrohahnia melloleitaoi (Schiapelli & Gerschman, 1942) new combination was transferred from Hahnia C.L. Koch, 1841, the male is described and illustrated for the first time, and the female is redescribed. Austrohahnia isophthalma (Mello-Leitão, 1941) new combination is also transferred from Hahnia and considered a nomen dubium. New geographic records of studied species are provided.

A new species of Chileotrecha Maury, 1987 (Solifugae: Ammotrechidae) from Argentina with notes on the genus.

The monotypic genus Chileotrecha Maury, 1987, includes Chileotrecha atacamensis Maury, 1987 from Atacama and Coquimbo regions in Chile. We describe Chileotrecha argentinensis n. sp., which is the first record of the genus from Argentina. Phylogenetic relationships of Chileotrecha with other genera of Ammotrechidae are discussed based on external morphology. We report for the first time the presence of blunt and clubbed setae in Ammotrechidae. We also report for the first time the presence of two pairs of microsetae in the posterior margin of genital plate and in the posterior margin of spiracular sternites I and II, and the presence of a single microseta on each side of postspiracular sternite I.