Theridiidae Sundevall, 1833, commonly known as cobweb spiders and comb-footed spiders, is a highly diverse spider family comprising 131 genera and 2,583 species worldwide (World Spider Catalog, 2025). The theridiid genus Stemmops Pickard-Cambridge, 1894, comprises 29 species, most of which are found in the Americas (World Spider Catalog, 2025). According to the latest spider species list for Guatemala (Herrera-Jordan, 2023), only two Stemmops species have been recorded: S. bicolor O. Pickard-Cambridge, 1894 and S. questus Levi, 1955. Here, we provide new distributional data for two additional Stemmops species, both collected while sifting leaf litter in a tropical forest in Guatemala.

All specimens studied are deposited in the Colección Nacional de Arácnidos (CNAN, curator: E. González), at Instituto de Biología, UNAM. Species identification was based on the works of Bryant (1933), Chamberlin & Ivie (1944), Chamé-Vázquez et al. (2020), and Levi (1955, 1964). Copulatory organs were imaged with an Amscope MU2000 camera coupled to an Amscope B660 microscope and stacked with Helicon Focus. Prior to imaging, the epigyne was cleared with clove oil.

Family Theridiidae Sundevall, 1833

Genus Stemmops Pickard-Cambridge, 1894

StemmopscambridgeiLevi, 1955

(Fig. 1a-b)

Distribution (Fig. 2). This species was known from Mexico and Honduras (World Spider Catalog, 2025).

Specimens examined.Guatemala: Chiquimula: Esquipulas, El Durazno, El Gigante (14.83825°N, 89.66762°W, 1551 m), oak-pine forest, leaf litter sifting, M. Barrios, M. Bustamante leg., 7/VIII/2013, 1 ♀ (CNAN). Alta Verapaz: Carcha, San Pablo Xicoc, Hidroelectrica Renacer (15.48106°N, 90.23499°W, 1332 m), oak-pine forest, leaf litter sifting, M. Barrios leg., 20/XII/2013, 3 ♀ (CNAN). Same as preceding, except (15.48669°N, 90.18735°W, 1135 m), riparian forest, 21/XII/2013, 1 ♂ 3 ♀ (CNAN).

Comments. This finding represents the first country record for Guatemala, filling a distributional gap between southern Mexico and northern Honduras (Levi, 1955; Chamé-Vázquez et al., 2020).

Stemmopsornatus(Bryant, 1933)

(Fig. 1c)

Distribution (Fig. 2). Previously, this species was known only from the United States (World Spider Catalog, 2025).

Specimens examined.Guatemala: Alta Verapaz: Carcha, San Pablo Xicoc, Hidroelectrica Renacer (15.48669°N, 90.18735°W, 1135 m), riparian forest, leaf litter sifting, M. Barrios leg., 21/XII/2013, 1 ♂ (CNAN).

Comments. This finding represents the first country record for Guatemala and the southernmost confirmed record in the Americas. While Levi (1955) primarily documented this species from the eastern United States, he later suggested a potential distribution extending from "the eastern United States possibly to Panama" (Levi, 1964: 74). This new record confirms the presence of this species in Central America.

Additionally, the abdomen of the examined male exhibits some variation from previous descriptions. While typically characterized by whitish spots (Bryant, 1933; Chamberlin, & Ivie, 1944), these markings appear diffuse and are not clearly visible in our specimen. This observation aligns with Levi (1955), who noted a color variation within the species. Furthermore, the conductor tip is wider and more coniform than that illustrated by Levi (1955: fig. 22).

Acknowledgments

We extend our gratitude to E. González Santillán (CNAN) for the loan of the specimens studied.

REFERENCES

Bryant, E. B. (1933). New and little known spiders from the United States. Bulletin of the Museum of Comparative Zoology, 74, 171-193.

Chamberlin, R. V., & Ivie, W. (1944). Spiders of the Georgia region of North America. Bulletin of the University of Utah, 35(9), 1-267.

Chamé-Vázquez, D., Jiménez, M.-L., & López Gálvez, U. (2020). Nuevos registros de arañas (Arachnida: Araneae) en el centro y sur de México. Revista de la Sociedad Entomológica Argentina, 79(4), 59-66. https://doi.org/10.25085/rsea.790411

Herrera-Jordan, K. (2023). Listado preliminar de las arañas (Arachnida: Araneae) de Guatemala. In J. C. Schuster, J. Yoshimoto, & J. Monzón Sierra (Eds.), Biodiversidad de Guatemala (Vol. III, pp. 208-226). Universidad del Valle de Guatemala.

Levi, H. W. (1955). The spider genera Oronota and Stemmops in North America, Central America and the West Indies (Araneae: Theridiidae). Annals of the Entomological Society of America, 48(5), 333-342. https://doi.org/10.1093/aesa/48.5.333

Levi, H. W. (1964). The spider genera Stemmops, Chrosiothes, and the new genus Cabello from America. Psyche, 71(2), 73-92. https://doi.org/10.1155/1964/60425

World Spider Catalog. (2025). World Spider Catalog (Version 25.5) [Database]. Natural History Museum Bern. http://wsc.nmbe.ch https://doi.org/10.24436/2

Notas de autor

ljimenez04@cibnor.mx

Información adicional

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