The BALA project: A pioneering monitoring of Azorean forest invertebrates over two decades (1999-2022).

Globally, there is a concerning decline in many insect populations, and this trend likely extends to all arthropods, potentially impacting unique island biota. Native non-endemic and endemic species on islands are under threat due to habitat destruction, with the introduction of exotic, and potentially invasive, species, further contributing to this decline. While long-term studies of plants and vertebrate fauna are available, long-term arthropod datasets are limited, hindering comparisons with better-studied taxa. The Biodiversity of Arthropods of the Laurisilva of the Azores (BALA) project has allowed gathering comprehensive data since 1997 in the Azorean Islands (Portugal), using standardised sampling methods across islands. The dataset includes arthropod counts from epigean (pitfall traps) and canopy-dwelling (beating samples) communities, enriched with species information, biogeographic origins, and IUCN categories. Metadata associated with the sample protocol and events, like sample identifier, archive number, sampled tree species, and trap type are also recorded. The database is available in multiple formats, including Darwin Core, which facilitates the ecological analysis of pressing environmental concerns, such as arthropod population declines and biological invasions.

Standardised inventories of spiders (Arachnida, Araneae) of Macaronesia III: dry habitats of Cabo Verde Archipelago (São Vicente and Santo Antão).

Background: With this publication, we contribute to the knowledge of the arachnofauna of Cabo Verde, focusing specifically on the Islands of Santo Antão and São Vicente. Data were obtained from samples collected as part of the project "Macaronesian Islands as a testing ground to assess biodiversity drivers at multiple scales" (FCT - MACDIV, 2015-2018). This project aimed to identify the factors influencing community assembly in Macaronesian islands. For the Cabo Verde Islands, we focused on dry habitats with the additional aim to revise the aracnofauna of this poorly-known fauna. We applied the COBRA (Conservation Oriented Biodiversity Rapid Assessment) sampling protocol in ten 50 m x 50 m dry shrub plots, with five on each of the two islands, using pitfall traps, sweep-netting and active search. Additional ad-hoc samples were also collected and reported. New information: Our sampling of spiders from Cabo Verde (Santo Antão and São Vicente) yielded a total of 3,368 specimens, of which 1300 (39%) were adults. The samples include 21 families, 87 species, 18 of which are morphospecies awaiting formal identification or description at species level. Species in the families Oxyopidae (2 spp.) and Araneidae (8 spp.) were the most abundant, making up 49% of the specimens. From the 68 named species, 14 are endemic to Cabo Verde, 40 are native non-endemic and 14 are introduced. The colonisation status of Cithaeronreimoseri Platnick, 1991 is unknown. Endemic species accounted for 24% (n = 818) of the specimens and native non-endemic for 63% (n = 2122). A total of 29 species were new records for Cabo Verde, with 15 for Santo Antão, seven for São Vicente and seven for both Islands.

How much biodiversity is concealed in the word 'biodiversity'?

Amidst a global biodiversity crisis1, the word 'biodiversity' has become indispensable for conservation and management2. Yet, biodiversity is often used as a buzzword in scientific literature. Resonant titles of papers claiming to have studied 'global biodiversity' may be used to promote research focused on a few taxonomic groups, habitats, or facets of biodiversity - taxonomic, (phylo)genetic, or functional. This usage may lead to extrapolating results outside the target systems of these studies with direct consequences for our understanding of life on Earth and its practical conservation. Here, we used a random sample of papers with the word 'biodiversity' in their title to take a long view of the use of this term. Despite improvements in analytical tools, monitoring technologies, and data availability3,4, we found that the taxonomic scope of research articles has not increased in recent years. We also show that studies with a wider taxonomic scope attract more citations and online attention. Our results have broad ramifications for understanding how extrapolating from studies with narrow taxonomic scope affects our view of global biodiversity and conservation.

The global spread of misinformation on spiders.

In the internet era, the digital architecture that keeps us connected and informed may also amplify the spread of misinformation. This problem is gaining global attention, as evidence accumulates that misinformation may interfere with democratic processes and undermine collective responses to environmental and health crises1,2. In an increasingly polluted information ecosystem, understanding the factors underlying the generation and spread of misinformation is becoming a pressing scientific and societal challenge3. Here, we studied the global spread of (mis-)information on spiders using a high-resolution global database of online newspaper articles on spider-human interactions, covering stories of spider-human encounters and biting events published from 2010-20204. We found that 47% of articles contained errors and 43% were sensationalist. Moreover, we show that the flow of spider-related news occurs within a highly interconnected global network and provide evidence that sensationalism is a key factor underlying the spread of misinformation.

For all audiences: Incorporating immature stages into standardised spider inventories has a major impact on the assessment of biodiversity patterns.

Although arthropods are the largest component of animal diversity, they are traditionally underrepresented in biological inventories and monitoring programmes. However, no biodiversity assessment can be considered informative without including them. Arthropod immature stages are often discarded during sorting, despite frequently representing more than half of the collected individuals. To date, little effort has been devoted to characterising the impact of discarding nonadult specimens on our diversity estimates. Here, we used a metabarcoding approach to analyse spiders from oak forests in the Iberian Peninsula, to assess (1) the contribution of juvenile stages to local diversity estimates, and (2) their effect on the diversity patterns (compositional differences) across assemblages. We further investigated the ability of metabarcoding to inform on abundance. We obtained 363 and 331 species as adults and juveniles, respectively. Including the species represented only by juveniles increased the species richness of the whole sampling in 35% with respect to those identified from adults. Differences in composition between assemblages were greatly reduced when immature stages were considered, especially across latitudes, possibly due to phenological differences. Moreover, our results revealed that metabarcoding data are to a certain extent quantitative, but some sort of taxonomic conversion factor may be necessary to provide accurate informative estimates. Although our findings do not question the relevance of the information provided by adult-based inventories, they also reveal that juveniles provide a novel and relevant layer of knowledge that, especially in areas with marked seasonality, may influence our interpretations, providing more accurate information from standardised biological inventories.

An expert-curated global database of online newspaper articles on spiders and spider bites.

Mass media plays an important role in the construction and circulation of risk perception associated with animals. Widely feared groups such as spiders frequently end up in the spotlight of traditional and social media. We compiled an expert-curated global database on the online newspaper coverage of human-spider encounters over the past ten years (2010-2020). This database includes information about the location of each human-spider encounter reported in the news article and a quantitative characterisation of the content-location, presence of photographs of spiders and bites, number and type of errors, consultation of experts, and a subjective assessment of sensationalism. In total, we collected 5348 unique news articles from 81 countries in 40 languages. The database refers to 211 identified and unidentified spider species and 2644 unique human-spider encounters (1121 bites and 147 as deadly bites). To facilitate data reuse, we explain the main caveats that need to be made when analysing this database and discuss research ideas and questions that can be explored with it.

SLAM Project - Long Term Ecological Study of the Impacts of Climate Change in the natural forest of Azores: IV - The spiders of Terceira and Pico Islands (2019-2021) and general diversity patterns after ten years of sampling.

Background: Long-term studies are key to understand the drivers of biodiversity erosion, such as land-use change and habitat degradation, climate change, invasive species or pollution. The long-term project SLAM (Long Term Ecological Study of the Impacts of Climate Change in the natural forest of Azores) started in 2012 and focuses on arthropod monitoring, using SLAM (Sea, Land and Air Malaise) traps, aiming to understand the impact of the drivers of biodiversity erosion on Azorean native forests (Azores, Portugal). This is the fourth contribution including SLAM project data and the second focused on the spider fauna (Arachnida, Araneae) of native forests on two islands (Pico and Terceira). In this contribution, we describe data collected between 2019 and 2021 and we analyse them together with a previously published database that covered the 2012-2019 period, in order to describe changes in species abundance patterns over the last ten years. New information: We present abundance data of Azorean spider species for the 2019-2021 period in two Azorean Islands (Terceira and Pico). We also present analyses of species distribution and abundance of the whole sampling period. In the period of 2019-2021, we collected a total of 5110 spider specimens, of which 2449 (48%) were adults. Most juveniles, with the exception of some exotic Erigoninae, were also included in the data presented in this paper, since the low diversity of spiders in the Azores allows a relatively precise species-level identification of this life-stage. We recorded a total of 45 species, belonging to 39 genera and 16 families. The ten most abundant species were composed mostly of endemic or native non-endemic species and only two exotic species (Tenuiphantestenuis (Blackwall, 1852) and Dysderacrocata C. L. Koch, 1838). They included 4308 individuals (84%) of all sampled specimens and were the dominant species in Azorean native forests. The family Linyphiidae was the richest and most abundant taxon, with 15 (33%) species and 2630 (51%) specimens. We report Cheiracanthiummildei L. Koch, 1864, a non-native species, from Pico Island for the first time. We found no new species records on Terceira Island. This publication contributes to increasing the baseline information for future long-term comparisons of the spiders on the studied sites and the knowledge of the arachnofauna of the native forests of Terceira and Pico, in terms of species abundance, distribution and diversity across seasons for a 10 years period.

SLAM Project - Long Term Ecological Study of the Impacts of Climate Change in the natural forests of Azores: V - New records of terrestrial arthropods after ten years of SLAM sampling.

Background: A long-term study monitoring arthropods (Arthropoda) is being conducted since 2012 in the forests of Azorean Islands. Named "SLAM - Long Term Ecological Study of the Impacts of Climate Change in the natural forest of Azores", this project aims to understand the impact of biodiversity erosion drivers in the distribution, abundance and diversity of Azorean arthropods. The current dataset represents arthropods that have been recorded using a total of 42 passive SLAM traps (Sea, Land and Air Malaise) deployed in native, mixed and exotic forest fragments in seven Azorean Islands (Flores, Faial, Pico, Graciosa, Terceira, São Miguel and Santa Maria). This manuscript is the fifth data-paper contribution, based on data from this long-term monitoring project. New information: We targeted taxa for species identification belonging to Arachnida (excluding Acari), Chilopoda, Diplopoda, Hexapoda (excluding Collembola, Lepidoptera, Diptera and Hymenoptera (but including only Formicidae)). Specimens were sampled over seven Azorean Islands during the 2012-2021 period. Spiders (Araneae) data from Pico and Terceira Islands are not included since they have been already published elsewhere (Costa and Borges 2021, Lhoumeau et al. 2022). We collected a total of 176007 specimens, of which 168565 (95.7%) were identified to the species or subspecies level. For Araneae and some Hemiptera species, juveniles are also included in this paper, since the low diversity in the Azores allows a relatively precise species-level identification of this life-stage. We recorded a total of 316 named species and subspecies, belonging to 25 orders, 106 families and 260 genera. The ten most abundant species were mostly endemic or native non-endemic (one Opiliones, one Archaeognatha and seven Hemiptera) and only one exotic species, the Julida Ommatoiulusmoreleti (Lucas, 1860). These ten species represent 107330 individuals (60%) of all sampled specimens and can be considered as the dominant species in the Azorean native forests for the target studied taxa. The Hemiptera were the most abundant taxa, with 90127 (50.4%) specimens. The Coleoptera were the most diverse with 30 (28.6%) families.We registered 72 new records for many of the islands (two for Flores, eight for Faial, 24 for Graciosa, 23 for Pico, eight for Terceira, three for São Miguel and four for Santa Maria). These records represent 58 species. None of them is new to the Azores Archipelago. Most of the new records are introduced species, all still with low abundance on the studied islands. This publication contributes to increasing the baseline information for future long-term comparisons of the arthropods of the studied sites and the knowledge of the arthropod fauna of the native forests of the Azores, in terms of species abundance, distribution and diversity throughout seasons and years.

The World Spider Trait database: a centralized global open repository for curated data on spider traits.

Spiders are a highly diversified group of arthropods and play an important role in terrestrial ecosystems as ubiquitous predators, which makes them a suitable group to test a variety of eco-evolutionary hypotheses. For this purpose, knowledge of a diverse range of species traits is required. Until now, data on spider traits have been scattered across thousands of publications produced for over two centuries and written in diverse languages. To facilitate access to such data, we developed an online database for archiving and accessing spider traits at a global scale. The database has been designed to accommodate a great variety of traits (e.g. ecological, behavioural and morphological) measured at individual, species or higher taxonomic levels. Records are accompanied by extensive metadata (e.g. location and method). The database is curated by an expert team, regularly updated and open to any user. A future goal of the growing database is to include all published and unpublished data on spider traits provided by experts worldwide and to facilitate broad cross-taxon assays in functional ecology and comparative biology. Database URL:https://spidertraits.sci.muni.cz/.

Standardised inventories of spiders (Arachnida, Araneae) on touristic trails of the native forests of the Azores (Portugal).

BACKGROUND: The sharp increase in tourist visitation of the Azores Archipelago from 2015 onwards raised concerns about the impacts of recreational tourism on native habitats. In response, a project was financed by the Azorean Government to investigate the drivers of biodiversity erosion associated with recreational tourism. Here, we present the data on spider biodiversity found on trails located within the native Azorean forests as they are home to several endemic species of great conservation value. We applied an optimised and standardised sampling protocol (COBRA) in twenty-three plots located in five trails on Terceira and São Miguel Islands and assessed diversity and abundance of spider species at different distances from the trail head and the trail itself. NEW INFORMATION: Of the 45 species (12435 specimens) collected, 13 were endemic to the Azores (9690 specimens), 10 native non-endemic (2047 specimens) and 22 introduced (698 specimens). This database will be the baseline of a long-term monitoring project for the assessment of touristic impacts on native forest trails. This methodology can also be used on other habitats and biogeograhical regions.

Arthropod diversity in two Historic Gardens in the Azores, Portugal.

The aim of our study was to characterise and compare the richness and composition of endemic, native (non-endemic) and introduced arthropod assemblages of two Azorean Historic Gardens with contrasting plant species composition. We hypothesised that Faial Botanic Garden would hold higher arthropod diversity and abundance of native and endemic arthropod species due to its larger native plant community. Species were collected using several arthropod standardised techniques between April 2017 and June 2018. We used the alpha diversity metrics (Hill series) and the partitioning of total beta diversity (ßtotal) into its replacement (ßrepl) and richness (ßrich) components, to analyse the adult and total arthropod community. The orders Araneae, Coleoptera and Hemiptera were also studied separately. Our results show that the number of exotic arthropod species exceeds the number of native and/or the endemic species in both gardens, but the arthropod community of Faial Botanic Garden exhibited a higher density of endemic and native species. Despite some minor exceptions, the geographic origins of plant communities largely influenced the arthropod species sampled in each garden. This study improves our knowledge about urban arthropod diversity in the Azores and shows how well-designed urban garden management and planning contribute to the conservation of native and endemic Azorean species.

Standardised inventories of spiders (Arachnida, Araneae) of Macaronesia II: The native forests and dry habitats of Madeira archipelago (Madeira and Porto Santo islands).

BACKGROUND: Here we present the data obtained from the samples collected as part of a large research project (MACDIV) which aims at understanding the drivers of spider (Araneae) community assembly in Macaronesian islands. To obtain the data, we applied the sampling protocol COBRA (Conservation Oriented Biodiversity Rapid Assessment), in twelve 50 m x 50 m native forest plots and five dry habitat plots on the island of Madeiraand in 5 dry habitat plots on the island of Porto Santo. Through this publication, we contribute to the knowledge of the arachnofauna of the Madeiran archipelago. NEW INFORMATION: From the samples that we collected, we obtained a total of 14,902 specimens, of which 49% were adults (7,263). We identified these specimens to 87 species and 18 morphospecies (undescribed), belonging to 26 families. Species of the family Linyphiidae dominated the samples, with 24 (morpho)species. Out of the 105 recorded (morpho)species, 34 were endemic, 26 native non-endemic, 22 introduced and 23 species of unknown origin. We report seven new records of possibly recently introduced species in the Madeiran archipelago. We also present 21 new records for Madeira island and 32 for Porto Santo (33 for the whole archipelago).

Globally distributed occurrences utilised in 200 spider species conservation profiles (Arachnida, Araneae).

BACKGROUND: Data on 200 species of spiders were collected to assess the global threat status of the group worldwide. To supplement existing digital occurrence records from GBIF, a dataset of new occurrence records was compiled for all species using published literature or online sources, from which geographic coordinates were extracted or interpreted from locality description data. NEW INFORMATION: A total of 5,104 occurrence records were obtained, of which 2,378 were from literature or online sources other than GBIF. Of these, 2,308 had coordinate data. Reporting years ranged from 1834 to 2017. Most records were from North America and Europe, with Brazil, China, India and Australia also well represented.

Standardised inventories of spiders (Arachnida, Araneae) of Macaronesia I: The native forests of the Azores (Pico and Terceira islands).

BACKGROUND: The data presented here come from samples collected as part of two recent research projects (NETBIOME - ISLANDBIODIV and FCT - MACDIV) which aimed at understanding the drivers of community assembly in Macaronesian islands. We applied the sampling protocol COBRA (Conservation Oriented Biodiversity Rapid Assessment, Cardoso 2009) in sixteen 50 m x 50 m native forest plots in the Azorean Islands of Pico (6 plots) and Terceira (10 plots) to assess spider diversity. Through this publication, we contribute to the knowledge of the arachnofauna of the Azores and, more specifically, to that of the islands of Pico and Terceira. NEW INFORMATION: The collected samples yielded 8,789 specimens, of which 45% were adults (3,970) belonging to 13 families, 36 species and three morphospecies that have yet to be described. Species of the family Linyphiidae dominated the samples, with 17 species and two morphospecies that have yet to be described (48% of the taxa). Out of the identified (morpho)species, 16 were introduced, 13 Azorean endemic (three of which were undescribed) and seven native (five of them Macaronesian endemics). We report the first record of the introduced species Haplodrassus signifer and Agyneta decora in Pico Island.

A DNA barcode-assisted annotated checklist of the spider (Arachnida, Araneae) communities associated to white oak woodlands in Spanish National Parks.

BACKGROUND: A large scale semi-quantitative biodiversity assessment was conducted in white oak woodlands in areas included in the Spanish Network of National Parks, as part of a project aimed at revealing biogeographic patterns and identify biodiversity drivers. The semi-quantitative COBRA sampling protocol was conducted in sixteen 1-ha plots across six national parks using a nested design. All adult specimens were identified to species level based on morphology. Uncertain delimitations and identifications due to either limited information of diagnostic characters or conflicting taxonomy were further investigated using DNA barcode information. NEW INFORMATION: We identified 376 species belonging to 190 genera in 39 families, from the 8,521 adults found amongst the 20,539 collected specimens. Faunistic results include the discovery of 7 new species to the Iberian Peninsula, 3 new species to Spain and 11 putative new species to science. As largely expected by environmental features, the southern parks showed a higher proportion of Iberian and Mediterranean species than the northern parks, where the Palearctic elements were largely dominant. The analysis of approximately 3,200 DNA barcodes generated in the present study, corroborated and provided finer resolution to the morphologically based delimitation and identification of specimens in some taxonomically challenging families. Specifically, molecular data confirmed putative new species with diagnosable morphology, identified overlooked lineages that may constitute new species, confirmed assignment of specimens of unknown sexes to species and identified cases of misidentifications and phenotypic polymorphisms.

Species conservation profiles of a random sample of world spiders IV: Scytodidae to Zoropsidae.

BACKGROUND: The IUCN Red List of Threatened Species is the most widely used information source on the extinction risk of species. One of the uses of the Red List is to evaluate and monitor the state of biodiversity and a possible approach for this purpose is the Red List Index (RLI). For many taxa, mainly hyperdiverse groups, it is not possible within available resources to assess all known species. In such cases, a random sample of species might be selected for assessment and the results derived from it extrapolated for the entire group - the Sampled Red List Index (SRLI). The current contribution is the final in four papers that will constitute the baseline of a future spider SRLI encompassing 200 species distributed across the world. NEW INFORMATION: A sample of 200 species of spiders were randomly selected from the World Spider Catalogue, an updated global database containing all recognised species names for the group. The selected species were classified taxonomically at the family level and the familes were ordered alphabetically. In this publication, we present the conservation profiles of 50 species belonging to the families alphabetically arranged between Scytodidae and Zoropsidae, which encompassed Scytodidae, Selenopidae, Sicariidae, Sparassidae, Tetrablemmidae, Tetragnathidae, Theraphosidae, Theridiidae, Theridiosomatidae, Thomisidae, Trochanteriidae, Zodariidae and Zoropsidae.

Species conservation profiles of a random sample of world spiders III: Oecobiidae to Salticidae.

BACKGROUND: The IUCN Red List of Threatened Species is the most widely used information source on the extinction risk of species. One of the uses of the Red List is to evaluate and monitor the state of biodiversity and a possible approach for this purpose is the Red List Index (RLI). For many taxa, mainly hyperdiverse groups, it is not possible within available resources to assess all known species. In such cases, a random sample of species might be selected for assessment and the results derived from it extrapolated for the entire group - the Sampled Red List Index (SRLI). The current contribution is the third in four papers that will constitute the baseline of a future spider SRLI encompassing 200 species distributed across the world. NEW INFORMATION: A sample of 200 species of spiders were randomly selected from the World Spider Catalogue, an updated global database containing all recognized species names for the group. The 200 selected species where divided taxonomically at the family level, and the familes were ordered alphabetically. In this publication, we present the conservation profiles of 58 species belonging to the famillies alphabetically arranged between Oecobiidae and Salticidae, which encompassed Oecobiidae, Oonopidae, Orsolobidae, Oxyopidae, Palpimanidae, Philodromidae, Pholcidae, Pisauridae, Prodidomidae and Salticidae.

Species conservation profiles of a random sample of world spiders II: Gnaphosidae to Nemesiidae.

BACKGROUND: The IUCN Red List of Threatened Species is the most widely used information source on the extinction risk of species. One of the uses of the Red List is to evaluate and monitor the state of biodiversity and a possible approach for this purpose is the Red List Index (RLI). For many taxa, mainly hyperdiverse groups, it is not possible within available resources to assess all known species. In such cases, a random sample of species might be selected for assessment and the results derived from it extrapolated for the entire group - the Sampled Red List Index (SRLI). The current contribution is the second in four papers that will constitute the baseline of a future spider SRLI encompassing 200 species distributed across the world. NEW INFORMATION: A sample of 200 species of spiders were randomly selected from the World Spider Catalogue, an updated global database containing all recognised species names for the group. The 200 selected species where divided taxonomically at the family level and the familes were ordered alphabetically. In this publication, we present the conservation profiles of 45 species belonging to the families alphabetically arranged between Gnaphosidae and Nemesiidae, which encompassed Gnaphosidae, Idiopidae, Linyphiidae, Liocranidae, Lycosidae, Micropholcommatidae, Mysmenidae and Nemesiidae.

Species conservation profiles of a random sample of world spiders I: Agelenidae to Filistatidae.

BACKGROUND: The IUCN Red List of Threatened Species is the most widely used information source on the extinction risk of species. One of the uses of the Red List is to evaluate and monitor the state of biodiversity and a possible approach for this purpose is the Red List Index (RLI). For many taxa, mainly hyperdiverse groups, it is not possible within available resources to assess all known species. In such cases, a random sample of species might be selected for assessment and the results derived from it extrapolated for the entire group - the Sampled Red List Index (SRLI). With the current contribution and the three following papers, we intend to create the first point in time of a future spider SRLI encompassing 200 species distributed across the world. NEW INFORMATION: A sample of 200 species of spiders were randomly selected from the World Spider Catalogue, an updated global database containing all recognised species names for the group. The 200 selected species where divided taxonomically at the family level and the familes were ordered alphabetically. In this publication, we present the conservation profiles of 46 species belonging to the famillies alphabetically arranged between Agelenidae and Filistatidae, which encompassed Agelenidae, Amaurobiidae, Anyphaenidae, Araneidae, Archaeidae, Barychelidae, Clubionidae, Corinnidae, Ctenidae, Ctenizidae, Cyatholipidae, Dictynidae, Dysderidae, Eresidae and Filistatidae.

Gauging megadiversity with optimized and standardized sampling protocols: A case for tropical forest spiders.

Characterizing and monitoring biodiversity and assessing its drivers require accurate and comparable data on species assemblages, which, in turn, should rely on efficient and standardized field collection. Unfortunately, protocols that follow such criteria remain scarce and it is unclear whether they can be applied to megadiverse communities, whose study can be particularly challenging. Here, we develop and evaluate the first optimized and standardized sampling protocol for megadiverse communities, using tropical forest spiders as a model taxon. We designed the protocol COBRA-TF (Conservation Oriented Biodiversity Rapid Assessment for Tropical Forests) using a large dataset of semiquantitative field data from different continents. This protocol combines samples of different collecting methods to obtain as many species as possible with minimum effort (optimized) and widest applicability and comparability (standardized). We ran sampling simulations to assess the efficiency of COBRA-TF (optimized, non-site-specific) and its reliability for estimating taxonomic, phylogenetic, and functional diversity, and community structure by comparing it with (1) commonly used expert-based ad hoc protocols (nonoptimized, site-specific) and (2) optimal protocols (optimized, site-specific). We then tested the performance and feasibility of COBRA-TF in the field. COBRA-TF yielded similar results as ad hoc protocols for species (observed and estimated) and family richness, phylogenetic and functional diversity, and species abundance distribution. Optimal protocols detected more species than COBRA-TF. Data from the field test showed high sampling completeness and yielded low numbers of singletons and doubletons. Optimized and standardized protocols can be as effective in sampling and studying megadiverse communities as traditional sampling, while allowing data comparison. Although our target taxa are spiders, COBRA-TF can be modified to apply to any highly diverse taxon and habitat as long as multiple collecting techniques exist and the unit effort per sample is comparable. Protocols such as COBRA-TF facilitate studying megadiverse communities and therefore may become essential tools for monitoring community changes in space and time, assessing the effects of disturbances and selecting conservation areas.