Evidence of Xysticus ulmi (Hahn) (Araneae: Thomisidae) Predation on Adult Cassida viridis Linnaeus (Coleoptera: Chrysomelidae)

Posted by
  Evidence of Xysticus ulmi (Hahn) (Araneae: Thomisidae) Predation on Adult Cassida viridis Linnaeus (Coleoptera: Chrysomelidae) Tortoise beetles (Chrysomelidae: Cassidinae) have several morphological and behavioral antipredator traits. For example, the soft larvae accumulate their feces and exuviae from previous instars to create a so-called “fecal shield” (Engel 1936; Kosior 1975), which functions as a defense against many predator guilds (Eisner and Eisner 2000; Eisner et al. 1968; Vencl et al. 1999, 2005; Vencl and Srygley 2013). Adults are characterized by their explanate and well-sclerotized pronota and elytra, which cover all soft parts of the body, thereby forming a tortoise-shaped shield (Buzzi 1988; Engel 1936; Jolivet 1997; Jolivet and Verma 2002; Selman 1988; Windsor et al. 1992) (Fig. 1A). Furthermore, the adults are known for their ability to grip firmly to surfaces with both tarsal claws and pads, which renders them difficult to capture (Buzzi 1988; Engel 1936; Joliv...

Taking the sting out of scorpions: Electrophysiological investigation of the relative efficacy of three antivenoms against medically significant Centruroides species

Posted by

 


Taking the sting out of scorpions: Electrophysiological investigation of the relative efficacy of three antivenoms against medically significant Centruroides species

Abstract

In this study, we report the innovative application of whole-cell patch-clamp electrophysiology in assessing broad-spectrum neutralisation by three different antivenoms, of venoms from the medically significant scorpion genus Centruroides. Envenomations by as many as 21 species from the Centruroides genus result in up to 300,000 envenomations per year in Mexico, which poses significant and potentially life-threatening pathophysiology. We first evaluated the in vitro manifestation of envenomation against two human voltage-gated sodium (hNaV) channel subtypes: hNaV1.4 and hNaV1.5, which are primarily expressed in skeletal muscles and cardiomyocytes, respectively. The neutralisation of venom activity was then characterised for three different antivenoms using a direct competition model against the more potent target, hNaV1.4. While broad-spectrum neutralisation was identified, variation in neutralisation arose for Centruroides elegans, C. limpidus, C. noxius and C. suffusus venoms, despite the presence of a number of these venoms within the immunising mixture. This raises questions regarding the truly “broad” neutralisation capacity of the antivenoms. This study not only extends previous validation of the in vitro investigation of antivenom efficacy utilising the whole-cell patch-clamp technique but also underscores the potential of this animal-free model in exploring cross-reactivity, experimental scalability, and most importantly, informing clinical management practices regarding the administration of antivenom in Mexico.

Campbell, S. I., Chow, C. Y., Neri-Castro, E., Alagón, A., Gómez, A., Soria, R., King, G. F., & Fry, B. G. (2024). Taking the sting out of scorpions: Electrophysiological investigation of the relative efficacy of three antivenoms against medically significant Centruroides species. Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology, 283, 109977. https://doi.org/10.1016/j.cbpc.2024.109977