An updated checklist of Azorean arthropods (Arthropoda)

Monitoring arthropods under the scope of the LIFE-BEETLES project: I - Baseline data with implementation of the Index of Biotic Integrity

Background

The urgent need for conservation efforts in response to the global biodiversity crisis is exemplified by initiatives, such as the EU LIFE BEETLES project. This project aims to preserve endangered arthropod species that are crucial for ecosystem functionality, with a focus on endemic beetle species in Flores, Pico and Terceira Islands (Azores, Portugal): Tarphiusfloresensis Borges & Serrano, 2017, Pseudanchomenusaptinoides (Tarnier, 1860) and Trechusterrabravensis Borges, Serrano & Amorim, 2004. These species are single island endemics respectively from Flores, Pico and Terceira. They are threatened by environmental degradation, facing the dual challenge of restricted distribution and habitat degradation due to the spread of invasive plants.The project aims to enhance habitat quality and biodiversity conservation through habitat restoration and plant invasive species control measures. These measures are funded by the European Commission and coordinated by the Azorean Environment Directorate-General. The current Data Paper evaluates the effectiveness of the LIFE BEETLES project in improving habitat quality and offers insights into the balance between habitat restoration efforts and endangered species conservation in island ecosystems, utilising as ecological indicator the Index of Biotic Integrity (IBI) framework.

New information

This study establishes a comprehensive database derived from a long-term arthropod monitoring survey that used SLAM (Sea, Land and Air Malaise) traps and pitfall traps. Our findings present a proxy for assessing the overall habitat quality for endemic invertebrates, using arthropods as main indicators.From September 2020 to June 2023, a total of 31 SLAM traps were monitored. The traps were set up as follows: seven in Flores (three in mixed forest and four in native forest), 10 in Pico (four in mixed forest and six in native forest) and 14 in Terceira (three in mixed forest and 11 in native forest). Traps were monitored every three months.In addition, we surveyed the epigean fauna in 19 transects with 15 non-attractive pitfall traps per transect. The transects were set up during two weeks at the end of August every year between 2020 and 2023. Eight transects were established in Flores, consisting of one in pasture, four in mixed forest and three in native forest. Six transects were established in Pico, consisting of two in pastures and four in native forest. Five transects were established in Terceira, consisting of two in mixed forest and three in native forest.A total of 243 arthropod taxa were recorded, with 207 identified at the species or subspecies level. These taxa belonged to four classes, 24 orders and 101 families. Out of the 207 identified taxa, 46 were endemic, 60 were native non-endemic, 80 were introduced and 21 were of indeterminate status. Habitat information is also provided, including general habitat and dominant species composition. This publication contributes to the conservation of highly threatened endemic beetles by assessing habitat quality, based on arthropod communities and habitat description (e.g. native or exotic vegetation).Using the Index of Biotic Integrity (IBI) to comparing pre- and post-intervention data, we found no significant change within the epigean community. In contrast, the understorey community sampled with SLAM traps experienced a slight global decrease in biotic integrity over the study period. These findings suggest that the short duration of the study may not be sufficient to detect significant changes, as ecosystem recovery often requires long-term monitoring. The observed changes in the understorey community may be attributed to disturbances from intervention activities, highlighting the need for ongoing monitoring to assess long-term ecological resilience and recovery.

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.

A multitaxa approach to biodiversity inventory in Matela protected area (Terceira, Azores, Portugal)

Background

This manuscript is the first contribution of the project, "Matela - uma ilha de biodiversidade" ("Matela - an island of biodiversity"), that aims to restore the native vegetation within the Azorean Protected Area of the Terceira Island Nature Park known as the "Protected Area for the Management of Habitats or Species of Matela" (TER08), situated on Terceira Island, the Azores Archipelago, Portugal. This small fragment of native forest, positioned at a low-medium altitude (300-400 m a.s.l.), is facing some conservation impacts as a consequence of the spread of different invasive exotic plant species, mainly Pittosporumundulatum, Rubusulmifolius and Hedychiumgardnerianum. The database we present encompasses diverse taxonomic groups, including bryophytes, vascular plants, arthropods, birds and mammals. It is derived from intensive sampling campaigns conducted in 2022, but some data from a previous vascular plant survey in 2015 were also included. The objective of this study was to provide an updated inventory of bryophytes, vascular plants, arthropods, birds and mammals within this protected area. In this way we are providing the reference conditions necessary for the monitoring of the impacts of the current ongoing restoration efforts within the project "Matela - an island of biodiversity". Whenever feasible, the present inventory is juxtaposed with historical data from previous surveys conducted in Matela.

New information

In the realm of bryophytes, our analysis revealed the presence of 75 taxa, comprising 44 mosses and 32 liverworts. Amongst these, 71 were indigenous, while three remained indeterminate and one, Campylopusintroflexus, was identified as invasive. A comparison with previous historical data revealed a decrease in species richness, which was partially counterbalanced by the discovery of 23 new recorded species in the area.Regarding vascular plants, we distinguished 54 species, comprising 28 indigenous and 26 introduced taxa. Almost 80% of the inventoried species (n = 43) were newly documented in Matela.The study of arthropods encompassed a total of 103 taxa. Within the realm of soil arthropods, we documented eight indigenous and 25 introduced taxa, witnessing the disappearance of endemic species alongside a substantial increase in introduced ones between 2002 and 2022. Canopy arthropods, totalling 36 indigenous and 18 introduced taxa, exhibited few changes when compared with data from 2002. SLAM traps captured 24 indigenous and 15 introduced arthropod taxa and no historical data are available for comparison.As for avian species, we noted 12 indigenous birds and one introduced species, confirming the presence of most of the historical recorded native species.The mammalian census revealed eight introduced species, setting new precedents for Matela, alongside the identification of one endemic species: the Azorean endemic bat Nyctalusazoreum.

Monitoring arthropods under the scope of LIFE-SNAILS project: I - Santa Maria Island baseline data with implementation of the Index of Biotic Integrity

Background

The database we introduce is a pivotal component of the LIFE SNAILS project (Support and Naturalisation in Areas of Importance for Land Snails). This initiative is dedicated to safeguarding three endangered species of terrestrial molluscs, specifically, two snails (Oxychilusagostinhoi Martins 1981 and Leptaxisminor Backhuys, 1975) and a semi-slug (Plutoniaangulosa (Morelet, 1860)), all of which are single island endemics from Santa Maria Island and face significant threats towards their populations.In this study, we established a comprehensive database derived from a long-term arthropod monitoring campaign utilising SLAM (Sea, Land, Air, Malaise) traps. Although molluscs were not the primary focus, our findings serve as a credible proxy for evaluating the overall habitat quality for endemic invertebrates, with arthropods serving as principal indicators. From September to December of 2022, a total of 11 SLAM traps were installed and monitored monthly in eleven sites of mixed forests of Santa Maria Island.

New information

Based on the 33 available samples (11 sites x 3 sampling periods), we recorded a total of 118 taxa of arthropods (of which 94 were identified at species or subspecies level), belonging to three classes, 14 orders and 62 families. From the 94 identified taxa, a total of 21 species were endemic, 31 native non-endemic, 32 introduced and 10 indeterminate. We also provide additional information of the habitat quality (Index of Biotic Integrity), including general habitat and dominant species composition.We registered three new records to the Island, the native bug Piezodoruslituratus (Fabricius, 1794) (Hemiptera, Pentatomidae), the Azorean endemic beetle Phloeosinusgillerforsi Bright, 1987 (Coleoptera, Curculionidae) and the exotic ant Hypoponerapunctatissima (Roger, 1859) (Hymenoptera, Formicidae) and one new record for the Azores Archipelago, the native beetle Cephenniumvalidum Assing & Meybohm, 2021 (Coleoptera, Staphylinidae, Scydmaeninae).This publication not only contributes to the conservation of highly threatened endemic molluscs, through an assessment of habitat quality, based on arthropod communities and habitat description (e.g. native or exotic vegetation), but also provides an updated inventory of arthropods from Santa Maria Island.

Effects of a short-term temperature increase on arthropod communities associated with pastures

The impact of climate change on islands is expected to cause dramatic consequences on native biodiversity. However, limited data are available for arthropod communities in island agroecosystems. In this study, we simulate a small-scale climatic change (average of +1.2°C), using Open Top Chambers (OTCs) in forage crops in the Azores Archipelago (Portugal) and test the responses of arthropod communities associated with intensively-managed pastures. At three sites, twenty 1 x 1 m plots were established: 10 treatment plots with OTCs and 10 control plots. Arthropods were sampled with pitfall traps on two sampling events (winter and summer of 2020). When considering all species collected, arthropods' abundance was lower in OTCs. Specific taxa, namely spiders and beetles, showed a fast response to the OTCs' presence. The assemblage of non-indigenous spiders well adapted to pastures showed a significant difference in diversity with a slightly greater richness, but lower abundance inside the warmer plots. However, the presence of OTCs resulted in a decrease in beetle richness and abundance. This decline may be attributed to the multiple effects of warming. Therefore, it is imperative to conduct further investigations to elucidate the ecological processes that underlie the observed patterns.

Assessing the effects of climate change on arthropod abundance in Azorean pastures: PASTURCLIM project's baseline monitoring data

Background

The data we present are part of the project PASTURCLIM (Impact of climate change on pasture's productivity and nutritional composition in the Azores). The project aims to assess the consequences of climate change (e.g. temperature increase) on the grass production and its quality for forage, as well as to assess changes in the arthropod communities associated with the Azorean intensive pastures. An in situ experiment was set up using Open Top Chambers (OTCs), in order to simulate an increasing of temperature (average of +1.2ºC) on pastures. In this contribution, we present the data relative to the arthropod sampling.

New information

We provide an inventory of all arthropods recorded inside OTCs and in control plots in three intensively managed pastures dominated by grasses in Terceira Island (Azores): two of them dominated by ryegrass, Loliummultiflorum Lam. (Poaceae), located respectively at 186 m and 301 m above sea level; and one field dominated by common velvetgrass, Holcuslanatus L. (Poaceae), located at an altitude of 385 m.A total of 41351 specimens were collected. Organisms collected belong to four classes, 15 orders, 60 families and 171 species/morphospecies (including 34 taxa identified only at order, family or genus level). Therefore, for only 137 taxa, we have a scientific name associated (n = 38918). A total of 75% of the species (n = 129 species) are considered introduced (including all the species with indeterminate colonisation status that are possibly also exotic species (n = 7622)), representing 71% of the total abundance (n = 29664 specimens). A total of 19% of the species (n = 33 species) are considered native non-endemic representing 28% of the total abundance (n = 11608 specimens). Only one endemic species was sampled, the wolf spider Pardosaacorensis Simon, 1883 (1% of the species), representing 0.2% of the total abundance (n = 79 specimens). Spiders (5056 specimens) and beetles (18310 specimens) were the dominant taxa representing, respectively, 20 and 78 morphospecies.Since the main aim of this study was to have a better knowledge on arthropod communities present in Azorean pastures under a simulated temperature increase, the principal novelty of this paper is the contribution with distribution and abundance data to a baseline knowledge on the future consequences of climate changes on arthropod communities in Azorean pastures.

Monitoring ten insect pests in selected orchards in three Azorean Islands: The project CUARENTAGRI

Background

The data we present are part of the CUARENTAGRI project, which involves all archipelagos of the Macaronesia (Azores, Madeira, Canary Islands and Cabo Verde). The project aims to: i) identify and evaluate the risks associated with the introduction of new arthropod pests; ii) study the population dynamics of selected arthropod pest species currently responsible for the damage of key target crops and iii) develop monitoring systems, based on prediction and/or population dynamics of the crop pests, creating warnings and a phytosanitary prevention system. In this contribution, we compile data for three Azorean Islands (Terceira, São Jorge and São Miguel Islands), where pheromone-baited traps were placed in pastures, potato fields and several orchards' types (apples, banana, chestnuts, olives, orange and strawberry), during three consecutive years (2020, 2021 and 2022).

New information

A total of 114,827 specimens of insects (Arthropoda, Insecta) were collected, belonging to four orders, six families and ten recorded pest species. A total of eight species are considered introduced (Cosmopolitessordidus (Germar, 1824), Drosophilasuzukii (Matsumura, 1931), Bactroceraoleae (Rossi, 1790), Ceratitiscapitata (Wiedemann, 1824), Phthorimaeaoperculella (Zeller, 1873), Cydiapomonella (Linnaeus, 1758), Cydiasplendana (Hübner, 1799) and Grapholitamolesta (Busck, 1916); n = 84,986 specimens) and two native non-endemic (Mythimnaunipuncta (Haworth, 1809) and Spodopteralittoralis (Boisduval, 1833); n = 17,465 specimens). This study intended to contribute to a better knowledge of the arthropods pests that can affect the Azorean crops and will serve as a baseline for future monitoring actions, pest risk assessments and prevention systems.