Latrodectus

Arthropods, including insects and arachnids, significantly affect humans as vectors for infectious diseases. Arthropod bites and stings commonly cause minor, usually self-limited reactions; however, some species are associated with more severe complications. Spider bites are rarely life-threatening. There are two medically relevant spiders in the United States. Widow spider (Latrodectus) envenomation can cause muscle spasm and severe pain that should be treated with analgesics and benzodiazepines. Antivenom is not widely available in the United States but may be considered for severe, refractory cases...

Black widow spiders ( Latrodectus sp.) are distributed worldwide, and in Albania the L. tredecimguttatus Rossi, 1790 has been the dominant spider. Other medically important spiders in Albania include the brown recluse with symptoms known as loxoscelism, the false black widow and the egg sac spiders; the last two inducing similar symptoms to a wasp sting. METHODS: The data analyzed is from a decade-long study of 125 patients hospitalized in the regional hospital of Fier County, in the Western Lowland of Albania from May 2009 and to October 2018...

Understanding factors affecting male mate choice can be important for tracking the dynamics of sexual selection in nature. Male brown widow spiders ( Latrodectus geometricus ) mate with adult as well as immature (subadult) females. Mating with adults involves costly courtship with a repertoire of signaling behaviors, and typically ends with cannibalism ("self-sacrifice" initiated by male somersault). Mating with subadults involves brief courtship with behavioral repertoire reduced to one component (vibration) and no cannibalism...

Alpha-latrotoxin (ɑLTx) is the component responsible for causing the pathophysiology in patients bitten by spiders from the genus Latrodectus, commonly known as black widow spiders. The current antivenom used to treat these envenomations in Mexico is produced using the venom of thousands of spiders, obtained through electrical stimulation. This work aimed to produce this protein as well as two of its fragments in a bacterial model, to evaluate their use as immunogens to produce neutralizing hyperimmune sera, in rabbits...

Temperature challenges are one of the leading abiotic causes of success or failure of non-native species in a novel environment, and this is particularly true for low temperatures. Establishing and reproducing in a novel thermal environment can alter survival, behavior, and traits related to fitness. It has been proposed that plasticity or adaptation of thermal tolerance may allow an introduced species to thrive, or that successful invaders may be those with a thermal breadth in their native habitat that encompasses their new environment...

BACKGROUND: The black widow spider has both extraordinarily neurotoxic venom and three-dimensional cobwebs composed of diverse types of silk. However, a high-quality reference genome for the black widow spider was still unavailable, which hindered deep understanding and application of the valuable biomass. FINDINGS: We assembled the Latrodectus elegans genome, including a genome size of 1.57 Gb with contig N50 of 4.34 Mb and scaffold N50 of 114.31 Mb. Hi-C scaffolding assigned 98...

The steroid hormone 20-hydroxyecdysone (20E) controls molting in arthropods. The timing of 20E production, and subsequent developmental transitions, is influenced by a variety of environmental factors including nutrition, photoperiod, and temperature, which is particularly relevant in the face of climate change. Environmental changes, combined with rapid urbanization, and the increasing prevalence of urban heat islands (UHI) have contributed to an overall decrease in biodiversity making it critical to understand how organisms respond to elevating global temperatures...

This review discusses the distinct envenomation syndromes produced by North American species of snakes and arthropods, specifically the Crotalinae subfamily of snakes, which includes cottonmouths, copperheads, and rattlesnakes; coral snakes; Latrodectus and Loxosceles species of arachnid; and Centruroides sculpturatus, the only species of North American scorpion capable of producing an envenomation syndrome. The authors discuss the epidemiology, pathophysiology, and presentation of these syndromes and emphasize the varying degrees to which these syndromes can manifest clinically...

The brown widow spider, Latrodectus geometricus , is a predator of a variety of agricultural insects and is also hazardous for humans. Its venom is a true pharmacopeia representing neurotoxic peptides targeting the ion channels and/or receptors of both vertebrates and invertebrates. The lack of transcriptomic information, however, limits our knowledge of the diversity of components present in its venom. The purpose of this study was two-fold: (1) carry out a transcriptomic analysis of the venom, and (2) investigate the bioactivity of the venom using an electrophysiological bioassay...

We report two confirmed human bite cases by Lactrodectus geometricus , also known as the brown widow spider. These are the first reported bite envenomation incidents by L. geometricus in Malaysia. The incidents occurred in Tawau, Sabah and Paka, Terengganu. Both men were bitten on their ear while putting on motorcycle helmets. The spiders appeared to have nested in the helmets. The dead specimens were collected and sent to the Invertebrate and Vertebrate Neurobiology Laboratory, Department of Parasitology, Universiti Malaya for identification...

There are many native species of animals with the potential to cause severe disease in Portugal. Of the four clinically relevant snake species, the vipers (Vipera latastei and Vipera seoanei) are the most concerning. They can cause severe disease and require in-hospital management, monitoring and specific treatment, including the administration of anti-snake venom serum. The Malpolon monspessulanus and Macroprotodon brevis snakes cause mostly localized clinical manifestations, which do not require specific treatment...

Spiders are often wrongly designated as responsible for cutaneous eruptions. We aim to describe spider bites and the spider species implicated in metropolitan France. A retrospective observational study was conducted for all reported cases of spider bites from 2007 to 2018 extracted from the French Poison Control Centers (PCCs) information system, after exclusion of non-native spiders. We described identification of the spider, level of certainty of the bite, symptoms and severity of cases. 1194 cases of spider bites met the inclusion criteria...

Latrotoxins (LaTXs) are presynaptic pore-forming neurotoxins found in the venom of Latrodectus spiders. The venom contains a toxic cocktail of seven LaTXs, with one of them targeting vertebrates (α-latrotoxin (α-LTX)), five specialized on insects (α, β, γ, δ, ε- latroinsectotoxins (LITs), and one on crustaceans (α-latrocrustatoxin (α-LCT)). LaTXs bind to specific receptors on the surface of neuronal cells, inducing the release of neurotransmitters either by directly stimulating exocytosis or by forming Ca2+ -conductive tetrameric pores in the membrane...

Humankind has always been fascinated by venomous animals, as their toxic substances have transformed them into symbols of power and mystery. Over the centuries, researchers have been trying to understand animal venoms, unveiling intricate mixtures of molecules and their biological effects. Among venomous animals, Latrodectus Walckenaer, 1805 (widow spiders) have become feared in many cultures worldwide due to their extremely neurotoxic venom. The Latrodectus genus encompasses 32 species broadly spread around the globe, 14 of which occur in the Americas...

Spider major ampullate (MA) silk is characterized by high strength and toughness and is adaptable across environments. Experiments depriving spiders of protein have enabled researchers to examine nutritionally induced changes in gene expression, protein structures, and bulk properties of MA silk. However, it has not been elucidated if it varies in a similar way at a nanoscale. Here we used Atomic Force Microscopy (AFM) to simultaneously examine the topographic, structural, and mechanical properties of silks spun by two species of spider, Argiope keyserlingi and Latrodectus hasselti, at a nanoscale when protein fed or deprived...

Widow spiders are widely known for their potent venom toxins that make them among the few spiders of medical concern. The latrotoxins are the most well-studied widow toxins and include both the vertebrate-specific latrotoxins and the insect-specific latroinsectotoxins (LITs). Previous studies have shown that toxins are not limited to expression in the venom glands of adult spiders; however, gaps exist in latrotoxin screening across all life stages for brown widows, Latrodectus geometricus and southern black widows, Latrodectus mactans...

Strategic responses to invasive Latrodectus widow spiders are a global challenge due to the risks they pose to health and ecosystems. Chemical strategies involving the use of pyrethroids are effective against adult spiders, but as their populations rebound, chemical control becomes costly and unsustainable for eradication. A major obstacle is the inefficacy of insecticides against eggs, which are covered by a protective silk egg sac. Eradication of invasive spiders must focus on destroying progeny. Here, the responses of eggs in egg sacs of two invasive Latrodectus spiders in Japan (Latrodectus hasseltii (Thorell) and Latrodectus geometricus (C...

Female choice may be linked to population density if the expected encounter rates with potential mates affects choosiness (the energy and risk engaged to express mate preferences). Choosiness should covary with male availability, which could be assessed using the social cues available during development. We tested whether the exposure of juvenile females to cues of male density affected the mechanisms of choosiness of adult Latrodectus hasselti spiders in two experiments simulating natural contexts. The juvenile females were exposed to (1) volatile chemicals from two densities of adult males (airborne cues), and (2) tactile, vibrational and chemical cues from adult males or other females (cohabitation cues)...

INTRODUCTION: Spider bites are often overestimated because there are no specific clinical or histopathological aspects that characterize them, and skin lesions that resemble a spider bite are often wrongly considered to be a "true spider bite". However, even in case of a true spider bite, it is almost impossible to confirm the biting species, since very often neither physicians nor patients are trained in spider identification. OBJECTIVE: The aim of this report is to provide clinicians with a rapid and simple recognition of the few Italian medically relevant spiders, in order to take relative medical measures in case of spider bites...

Spiders are one of the most important orders of Arachnida comprising more than 48,000 species in the world. Except for families Uloboridae and Holarchaeidae, all others are classified as the venomous spider. However, only about 200 species are medically relevant and cause public health problems or even death. In Iran, there are 51 families and 763 species of spiders, of which the families, Theridiidae and Sicariidae are dangerous for the human being, and the first one is more prevalent. The Latrodectus is considered one of the most poisonous spiders in the world and Iran...