M. Alex Smith

Abstract We present the first dataset collection of arthropod diversity from ten terrestrial sites in the Neotropical Eastern Pacific Bioregion, in the territories of Costa Rica, Ecuador, Panama, and the Galapagos and Cocos Islands. The twenty–five datasets comprise 1–7 years of sampling. Together, we document a total of 952,087 arthropod specimens and 45,812 BINs. The datasets are distributed in 1 phylum, 7 classes, 39 orders, 556 families, and 2,318 genera.

INTRODUCTION Mountains constitute <25% of the world's landmass and yet contain approximately 87% of the world's species of amphibians, mammals and birds, making them one of the most species-rich terrestrial habitats in the world (Myers et al., 2000; Rahbek et al., 2019). However, mountain biodiversity, especially in the tropics, is extremely vulnerable to climate change (Deutsch et al., 2008; Raxworthy et al., 2008).

Abundance Regardless of site, total ant abundance on orange tree leaves was driven by primarily by bromeliad-associated species, the ant species that we observed nesting in bromeliads at least once (Table 1, Fig 2). Total ant abundances were similar between the Before period, which coincided with the end of the dry season, and the After period, which was a few weeks after the start of the wet season (Fig 2A). Ant abundances were consistently higher at site ER than at site CP (Fig 2A).