Search Results (16)

Seven species of Hemiscorpius Peters, 1861 have been recorded in Iran. Due to the medical importance of this genus, the scorpion populations of southern Kerman Province, in the south of Iran, were studied. Scorpion specimens were collected in 2023 and 2024 from mountainous areas in Bam and Jiroft counties. Morphological, morphometric, and molecular data revealed a new species, described herein as Hemiscorpius jiroftensis sp. n. The genetic distances between the new species and other species of Hemiscorpius varied from 0.105 with samples of H. lepturus from Iran to 0.138 with samples of H. enischnochela. The Jebal Barez Mountains appear to have provided a geographical barrier, separating the new species from its closest relative, Hemiscorpius acanthocercus Monod & Lourenço, 2005. It is important to understand the geographical distributions and morphological differences among the species of Hemiscorpius to implement appropriate medical responses to envenomation by these scorpions. Full article

Background/Objectives: Arachnids are a megadiverse arthropod group. The present study investigated the chromosomes of pedipalpid tetrapulmonates (orders Amblypygi, Thelyphonida, Schizomida) and two arachnid orders of uncertain phylogenetic placement, Ricinulei and Solifugae, to reconstruct their karyotype evolution. Except for amblypygids, the cytogenetics of these arachnid orders was almost unknown prior to the present study. Methods: Chromosomes were investigated using methods of standard (Giemsa-stained preparations, banding techniques) and molecular cytogenetics (fluorescence in situ hybridization, comparative genomic hybridization). Results and Conclusions: New data for 38 species, combined with previously published data, suggest that ancestral arachnids possessed low to moderate 2n (22–40), monocentric chromosomes, one nucleolus organizer region (NOR), low levels of heterochromatin and recombinations, and no or homomorphic sex chromosomes. Karyotypes of Pedipalpi and Solifugae diversified via centric fusions, pericentric inversions, and changes in the pattern of NORs and, in solifuges, also through tandem fusions. Some solifuges display an enormous amount of constitutive heterochromatin and high NOR number. It is hypothesized that the common ancestor of amblypygids, thelyphonids, and spiders exhibited a homomorphic XY system, and that telomeric heterochromatin and NORs were involved in the evolution of amblypygid sex chromosomes. The new findings support the Cephalosomata clade (acariforms, palpigrades, and solifuges). Hypotheses concerning the origin of acariform holocentric chromosomes are presented. Unlike current phylogenetic hypotheses, the results suggest a sister relationship between Schizomida and a clade comprising other tetrapulmonates as well as a polyploidization in the common ancestor of the clade comprising Araneae, Amblypygi, and Thelyphonida. Full article

Mastigoproctus Pocock, 1894, is the most speciose genus in the thelyphonid subfamily Mastigoproctinae Speijer, 1933, with eighteen described species distributed from the Southern United States to Colombia and Venezuela. Ten of these species occur in Mexico. In the present contribution, Mastigoproctus spinifemoratus, sp. nov., is described based on an adult male and two juveniles from Eastern Nuevo León and Southwestern Tamaulipas, Mexico. It differs from five other species of Mastigoproctus, in which spiniform tubercles are present on the retrolateral surface of the pedipalp femur, in the ventrally directed epistome of the carapace, and the absence of an accessory spine on the prodorsal margin of the pedipalp trochanter. The new species raises the number of Mastigoproctus species to nineteen and the number in Mexico to eleven. Full article

Cavernicolous scorpions are difficult to collect and study due to their often inaccessible habitats. Some have evolved unique morphological adaptations, known as troglomorphies, including reduced sclerotization and pigmentation, reduction and/or loss of eyes, attenuation and elongation of the appendages, which assist them to thrive in dark, humid and low-energy input environments. Cavernicolous scorpions are classified into accidentals, trogloxenes, troglophiles, and troglobites. The Balkans, and particularly the Dinaric Karst region, host a diverse cave-adapted fauna, including scorpions. Despite an 1895 report of a blind scorpion from Bosnia and Herzegovina, the first truly troglobitic European scorpion, Euscorpius studentium Karaman, 2020, was only described a few years ago, based on two immature specimens. In the present contribution, this unique species is redescribed based on the first adult specimens; the ecological classification of all currently known cavernicolous Euscorpiidae Laurie, 1896, is updated; a key to the identification of cavernicolous scorpions occurring in the Dinaric Karst is provided; and the historical and geographical factors affecting the distribution and conservation of cavernicolous scorpions in the Balkans is reviewed. Full article

Eighteen new cases of teratology and other abnormalities within scorpions are presented, representing new cases of metasomal duplication, mesosomal anomaly, telson anomaly, albinism, and abnormal pigmentation. Furthermore, recently published literature on other scorpion anomalies are tabulated to update the recent 2023 checklist of scorpion teratology which charted all known literature up to the aforementioned work. Full article

Due to their continuous growth, reclusive nature, and low vagility, the distributions and species limits of many whip spiders (Amblypygi Thorell, 1883) remain poorly understood, and much cryptic diversity remains unrecognized. Past attempts to separate the historical “forms” of Paraphrynus Moreno, 1940 into morphologically diagnosable species resulted, for example, in the division of Paraphrynus mexicanus (Bilimek, 1867) into three species—the nominotypical form, Paraphrynus cubensis Quintero, 1983, and Paraphrynus carolynae Armas, 2012. Nevertheless, the limitations of conservative morphology continue to hinder progress towards clarifying the diversity of Paraphrynus. One such example concerns P. carolynae, distributed from Arizona to central Mexico as currently defined. Through the acquisition of new, freshly collected material, the discovery of novel morphological characters, and molecular systematics analyses, it became apparent that P. carolynae comprises at least two morphologically diagnosable species. In this present contribution, the northernmost population of P. carolynae occurring in Arizona and California is described as a new species, Paraphrynus tokdod, sp. nov., raising the number of species in the genus to 22. This investigation also revealed more variation than expected in the secondary spine counts of the pedipalps and the trichobothrial counts of leg IV, previously used for species delimitation in Paraphrynus, suggesting that such characters should be used with caution. Full article

The house fly Musca domestica L. is one of the most common insects of veterinary and medical importance worldwide; its ability to develop resistance to a large number of insecticides is well known. Many studies support the involvement of cytochrome P-450-dependent monooxygenases (P450) in the development of resistance to pyrethroids, neonicotinoids, carbamates, and organophosphates among insects. In this paper, the monooxygenase activity and expression level of CYP6D1 were studied for the first time in a chlorfenapyr-resistant strain of house fly. Our studies demonstrated that P450 activity in adults of the susceptible strain (Lab TY) and chlorfenapyr-resistant strain (ChlA) was 1.56–4.05-fold higher than that in larvae. In females of the Lab TY and ChlA strains, this activity was 1.53- and 1.57-fold higher, respectively (p < 0.05), than that in males, and in contrast, the expression level of CYP6D1 was 21- and 8-fold lower, respectively. The monooxygenase activity did not vary between larvae of the susceptible strain Lab TY and the chlorfenapyr-resistant strain ChlA. Activity in females and males of the ChlA strain exceeded that in the Lab TY strain specimens by 1.54 (p = 0.08) and 1.83 (p < 0.05) times, respectively, with the same level of CYP6D1 expression. PCR-RFLP analysis revealed a previously undescribed mutation in the promoter region of the CYP6D1 gene in adults of the Lab TY and ChlA strains, and it did not affect the gene expression level. The obtained results show that the development of resistance to chlorfenapyr in M. domestica is accompanied by an increase in P450-monooxygenase activity without changes in CYP6D1 expression. Full article

Orb-weaver spiders produce upwards of seven different types of silk, each with unique material properties. We focus on the adhesive within orb-weaving spider webs, aggregate glue silk. These droplets are composed of three main components: water, glycoproteins, and a wide range of low molecular mass compounds (LMMCs). These LMMCs are known to play a crucial role in maintaining the material properties of the glycoproteins, aid in water absorption from the environment, and increase surface adhesion. Orb-weavers within the Cyrtarachninae subfamily are moth specialists and have evolved glue droplets with novel material properties. This study investigated the biochemical composition and diversity of the LMMCs present in the aggregate glue of eight moth-specialist species and compared them with five generalist orb-weavers using nuclear magnetic resonance (NMR) spectroscopy. We hypothesized that the novel drying ability of moth-specialist glue was accompanied by novel LMMCs and lower overall percentages by silk weight of LMMCs. We measured no difference in LMMC weight by the type of prey specialization, but observed novel compositions in the glue of all eight moth-catching species. Further, we quantified the presence of a previously reported but unidentified compound that appears in the glue of all moth specialists. These silks can provide insight into the functions of bioadhesives and inform our own synthetic adhesives. Full article

Herein, we redescribe Neostenotarsus guianensis (Caporiacco, 1954) nearly seven decades after its original description. In the original description of Neostenotarsus scissistylus Tesmoingt & Schmidt, 2002, we found characters incongruent with N. guianensis, namely, the purported presence of serration on the prolateral keels of the palpal bulb; a narrower apical third of the embolus; the absence of a patch of bristles on the retrolateral face of the palpal tibia and of a baso-retrolateral protuberance on metatarsus I; and a shorter and more apically situated megaspine on the retrolateral branch of the tibial apophyses. The characters from its original description are discussed. N. scissistylus stat. rev. has been revalidated until such time as the type material, or topotypic material, can be examined by future workers. Full article

The type material of Xenesthis colombiana Simon, 1891, X. immanis Ausserer, 1875, and X. monstrosa Pocock, 1903, are redescribed, with additional specimens of X. colombiana recorded. A neotype is designated for Xenesthis intermedia Schiapelli and Gerschman, 1945, as the holotype is lost; the female is redescribed, and the male is described for the first time. A new species, Xenesthis avanzadora sp. nov., is described from Venezuela based on a holotype male. Full article

Nowadays, the use of pesticides is, as before, the most common way to control arthropod plant pests and the ectoparasites of animals. The sublethal effects of pesticides on insects can appear at different levels, from genetics to populations, and the study of these effects is important for a better understanding of the environmental and evolutionary patterns of pesticidal resistance. The current study aimed to assess the sublethal effects of chlorfenapyr and fipronil on the activities of detoxifying enzymes (carboxylesterase—CarE, acetylcholinesterase—AChE, glutathione-S-transferase—GST, and cytochrome P450 monooxygenase—P450) in adults Musca domestica L. The insects were exposure to insecticides by a no-choice feeding test and the enzyme activities and the AChE kinetic parameters were examined in female and male specimens at 24 h after their exposure. According to Tukey’s test, the CarE activity was statistically significantly decreased by 29.63% in the females of M. domestica after an exposure to chlorfenapyr at a concentration of 0.015% when compared to the controls (p ≤ 0.05). An exposure to the sublethal concentration of fipronil (0.001%) was followed by a slightly decrease in the specific activity (33.20%, p ≤ 0.05) and the main kinetic parameters (Vmax, Km) of AChE in females in comparison with the control values. The GST and P450 activities had not significantly changed in M. domestica males and females 24 h after their exposure to chlorfenapyr and fipronil at sublethal concentrations. The results suggest that the males and females of M. domestica displayed biochemically different responses to fipronil, that is a neurotoxin, and chlorfenapyr, that is a decoupler of oxidative phosphorylation. Further research needs to be addressed to the molecular mechanisms underlying the peculiarities of the insect enzyme responses to different insecticides. Full article

Spiders use various combinations of silks, adhesives, and behaviors to ensnare prey. One common but difficult-to-catch prey is moths. They easily escape typical orb-webs because their bodies are covered in tiny sacrificial scales that flake off when in contact with the web’s adhesives. This defense is defeated by spiders of the sub-family of Cyrtarachninae—moth-catching specialists who combine changes in orb-web structure, predatory behavior, and chemistry of the aggregate glue placed in those webs. The most extreme changes in web structure are shown by the bolas spiders which create only one or two glue droplets at the end of a single thread. They prey on male moths by releasing pheromones to draw them close. Here, we confirm the hypothesis that the spinning behavior of the spider is directly used to spin its glue droplets using a high-speed video camera to observe the captured behavior of the bolas spider Cladomelea akermani as it actively spins its body and bolas. We use the kinematics of the spider and bolas to begin to quantify and model the physical and mechanical properties of the bolas during prey capture. We then examine why this species chooses to spin its body, an energetically costly behavior, during prey capture. We test the hypothesis that spinning helps to spread pheromones by creating a computational fluid dynamics model of airflow within an open field and comparing it to that of airflow within a tree, a common environment for bolas spiders that do not spin. Spinning in an open environment creates turbulent air, spreading pheromones further and creating a pocket of pheromones. Conversely, spinning within a tree does little to affect the natural airflow. Full article