New Insight Into the Evolutionary Arms Race Between Spider Egg Sac Pseudoparasitoids and Active Maternal Care by the Spiders

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  New Insight Into the Evolutionary Arms Race Between Spider Egg Sac Pseudoparasitoids and Active Maternal Care by the Spiders ABSTRACT Pseudoparasitoids can lead to high mortality in spider egg sacs, and in some cases, they reduce the reproductive success of a spider female to zero. On the other hand, a species that develops within the spider's egg sac uses a limited resource derived from a single egg sac for its larval development. Therefore, the most crucial behaviour that increases the fitness of free-living pseudoparasitoid females is choosing the best host for their offspring. We analysed various points of the counter-adaptations of the spider egg sac pseudoparasitoid and spiders exhibiting active maternal care, utilising the ichneumonid  Hidryta fusiventris  (Thomson, 1873) and the wolf spider  Pardosa lugubris  (Walckenaer, 1802). We showed that the oviposition decision of  H. fusiventris  is based on the spider's egg sac size and that the fema...

First epidemiological reports and urban range extension of Tityus trivittatus Kraepelin, 1898 (Scorpiones: Buthidae) in Paraná, Brazil

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First epidemiological reports and urban range extension of Tityus trivittatus Kraepelin, 1898 (Scorpiones: Buthidae) in Paraná, Brazil

Abstract

The scorpion genus Tityus Koch, 1836, (Buthidae) includes most of the medically significant species in South America. Tityus trivittatus Kraepelin, 1898 occurs in urban areas and remnants of wet Chaco, Cerrado, and Atlantic Forest in Paraguay and Brazil. Despite a low overall risk of mortality, its wide distribution, parthenogenesis, and synanthropy, pose potential public health concerns. In Brazil, the envenomation cases remain largely unknown. Here we present the first epidemiological reports of this species in Brazil (municipality of Foz do Iguaçu), including new occurrences in the state of Paraná. In addition, we also estimate the spatial factors influencing the records of T. trivittatus in Paraná based on the examined material. A total of 355 specimens were recorded and examined, with proximity to populated areas being the main factor influencing the species sampling bias. For the epidemiological reports, all sting cases involved local pain and occurred typically in feet, hands or legs. All cases were considered successfully treated by the local medical professionals These findings highlight the need for enhanced surveillance of T. trivittatus in southern Brazil.

Goldoni, P. A. M., Iniesta, L. F. M., Cequinel, J. C., Marques-da-Silva, E., & Brescovit, A. D. (2025). First epidemiological reports and urban range extension of Tityus trivittatus Kraepelin, 1898 (Scorpiones: Buthidae) in Paraná, Brazil. STUDIES IN ENVIRONMENTAL AND ANIMAL SCIENCES, 6(2), e18435. https://doi.org/10.54020/seasv6n2-005