The neonicotinoid imidacloprid impairs the predatory performance and functional response of the jumping spider Helpis minitabunda (Araneae, Salticidae)

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  The neonicotinoid imidacloprid impairs the predatory performance and functional response of the jumping spider Helpis minitabunda (Araneae, Salticidae) Abstract The neonicotinoid imidacloprid can cause lethal and sublethal effects in non-target organisms, including impaired behavior, reduced fertility, disrupted locomotion, and reduced predatory performance in arthropods. Spiders are among the most abundant arthropod predators in terrestrial ecosystems, including agricultural ecosystems, yet the effects of neonicotinoids on the predatory function of jumping spiders remain poorly understood. The functional response of a predator describes how predation rates change with prey density and is key to understanding predator–prey dynamics. We tested whether acute exposure to a commercial formulation of imidacloprid at field-recommended concentrations alters the functional response of the Aussie bronze jumping spider, Helpis minitabunda (L. Koch, 1880). We compared the predation of treat...

High diversity and population structure in a widespread tarantula Sickius longibulbi (Mygalomorphae: Theraphosidae)

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High diversity and population structure in a widespread tarantula Sickius longibulbi (Mygalomorphae: Theraphosidae)

ABSTRACT

Sickius Soares & Camargo, 1948 is a monotypic genus (Sickius longibulbi) characterized by a broad geographic distribution across Brazil and conservative morphology. Notably, females lack spermathecae, and males possess palpal bulb with a long embolus, both traits with taxonomic importance. The genus belongs to the infraorder Mygalomorphae, a group with intricate taxonomic challenges due to uniform morphology, complicating species delimitation. In the present study, we employed an integrative taxonomic approach, combining mitochondrial DNA sequences of the Cytochrome Oxidase I (COI) gene with Fourier Elliptical Analysis of the male palpal bulb shape to investigate lineage differentiation and evolutionary patterns within the genus Sickius. We observed genetic structured populations along with morphometric variation and geographic distribution, except for the two lineages localized in northeast Cerrado. We retain S. longibulbi as a single species with great diversity and possibly undergoing a process of divergence. Future studies with larger sample sizes are encouraged to confirm these findings and further investigate the evolutionary history of the genus.
Groppo, B. B., Morales, M. J., Belintani, T., & Guadanucci, J. P. L. (2025). High diversity and population structure in a widespread tarantula Sickius longibulbi (Mygalomorphae: Theraphosidae). Zoologischer Anzeiger. https://doi.org/10.1016/j.jcz.2025.08.007