Chemical Secretion Use Varies Among Species but Lacks a Straightforward Relationship With Other Defenses in Neotropical Opiliones

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  Chemical Secretion Use Varies Among Species but Lacks a Straightforward Relationship With Other Defenses in Neotropical Opiliones ABSTRACT Chemical secretion deployment is a widespread defensive strategy in arthropods, typically aimed at surviving encounters with predators. However, the ecological forces shaping variation in its use across species remain unclear. We quantified chemical secretion behavior in 11 sympatric species of Prionostemma within the understudied arachnid order Opiliones. We surveyed species in two distinct forests in Costa Rica and tested their secretion propensity when stimulated, and whether these differences correlate with interspecific variation in morphology, leg-loss levels, or social behavior. We found that species varied in their tendency to release chemical secretions, forming a continuous gradient from taxa that rarely secreted to those that secreted in nearly all encounters. However, this variation was not explained by body size or leg loss. Spec...

Diversity and Abundance of Spiders (Araneae) in Different Habitats in Mt. Lantoy, Cebu, Philippines

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Diversity and Abundance of Spiders (Araneae) in Different Habitats in Mt. Lantoy, Cebu, Philippines

Abstract

Spiders are essential Tecological regulators that help maintain ecosystem stability through their roles as both predators and prey in food webs. Despite their importance, information on their diversity and distribution is still scarce, especially in regions that remain poorly explored. This study aims to assess the abundance and diversity of spiders across different habitats at Mt. Lantoy: Forest, Riparian, Plantation, and Grassland. A combination of search-and-capture techniques and beat-sheet methods was employed during a 160-man-hour sampling period. The study documented 276 individuals across 101 species in 20 families. Among the families, Araneidae exhibited the highest species richness with 35 species, while Tetragnatha cf. ceylonica was the most abundant species, with 16 individuals. Nine recorded species are Philippine endemics (Acusilas dahoneus, Gasteracantha parangdiadesmia, Chrysso tiboli, Neoscona facundoi, Neoscona aldinei, Nusatidia luzonica, Phlogiellus baeri, Phintella piatensis, and Lepidemathis sericea) and eight species are classified as threatened under DENR Administrative Order 2019-09 (Cytophora exanthematica, Eriovixia laglaizei, Neoscona punctigera, Neoscona aldinei, Neoscona vigilans, Parawixia dehaani, Poltys illepidus, and Phlogiellus baeri); two species — Neoscona aldinei and Phlogiellus baeri — carry both endemic and threatened status, yielding 15 unique conservation-priority species in total. Forest and riparian had significantly higher plot-level abundance and species richness than plantation and grassland; forest and riparian were not significantly different from each other. These findings highlight Mt. Lantoy as a key habitat for spider populations, underscoring its value for future conservation initiatives and biodiversity management.

Fortuna,  J.G.A.;  Alburo,  R.P.; van Steenhuyse, T.J.L.; Olmilla,  R.C;  Alvarez,  J.P.L; Alburo,   H.M. Diversity  and abundance of spiders (Araneae)  in  different habitats in Mt. Lantoy, Cebu, Philippines. ASEAN   J. Sci. Tech. Report. 2026, 29(8), e265024. https://doi.org/10.55164/ajstr.v29i8.265024