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...

An eyeless new species of Monoblemma Gertsch, 1941 (Araneae: Tetrablemmidae) from Venezuela, with a new record of the single-eyed Monoblemma unicum Gertsch, 1941 from the Dominican Republic

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An eyeless new species of Monoblemma Gertsch, 1941 (Araneae: Tetrablemmidae) from Venezuela, with a new record of the single-eyed Monoblemma unicum Gertsch, 1941 from the Dominican Republic

The genus Monoblemma Gertsch, 1941 was recently revised by Martínez (2025) and currently comprises four species, mainly distributed in the Caribbean (World Spider Catalog 2026). Species of the genus exhibit remarkable variation in eye number, ranging from completely eyeless forms, such as Monoblemma becki Brignoli, 1978, to a single-eyed condition, with the eye positioned at the margin of the clypeal declivity in M. unicum Gertsch, 1941, and to four-eyed species, such as M. cambridgei (Bryant, 1940) and M. cubaense Martínez, 2025. In the original description of M. unicum, Gertsch (1941) noted that, because only a single specimen was available, the presence of one median eye might represent an abnormal condition. However, he also suggested that its median position and apparently normal development indicated that it was likely a constant feature of the species, probably resulting from the fusion of the anterior eyes present in species with two or four eyes. The discovery of a second specimen of Monoblemma unicum from the Dominican Republic exhibiting the same ocular condition confirms Gertsch’s hypothesis and supports the interpretation of the single eye as a stable, species-specific character. Additionally, a new eyeless species from Sucre, Venezuela is described based on both sexes, representing the second eyeless species in the genus. An updated distribution map and an identification key to all species of the genus are also provided.

 Martínez, L. (2026) An eyeless new species of Monoblemma Gertsch, 1941 (Araneae: Tetrablemmidae) from Venezuela, with a new record of the single-eyed Monoblemma unicum Gertsch, 1941 from the Dominican Republic. Zootaxa, 5787 (2), 394–400. https://doi.org/10.11646/zootaxa.5787.2.12