The main objective is to provide an inventory of the Staphylinidae (Coleoptera, Insecta), based on a compilation of records from long-term monitoring sampling campaigns performed in eight islands of Azores between 1990 and 2015. In addition, an updated checklist of Azorean Staphylinidae is provided.

This contribution is part of a series of publications on the distribution and abundance of Azorean arthropods (Borges et al. 2016, Borges et al. 2017) and updates the latest checklist of Azorean Staphylinidae (see Assing 2010) .

Most data come from the following studies (see also Suppl. material 1): “1” – Confirmed occurrence, (see Assing 2010 list); BALA - records based on BALA protocol (see Borges et al. 2016; samples part of current study); LAND-USE (see Cardoso et al. 2009, samples part of current study); MACDIV (see Malumbres-Olarte et al. 2019); ASSING – Non-standardised samples of one of us (Volker Assing) (part of current study); Marcelino - Marcelino et al. (2021); INTERF (data from project INTERFRUTA part of current study); WET – from Borges et al. (2018); AGRO – see (Borges et al. 2021b); SLAM - Long term monitoring of Azorean forests using SLAM traps for Terceira Island (see Matthews et al. 2018, Borges et al. 2020, Tsafack et al. 2021); SLAM for other islands (unpublished data); ASSING 2013 (new species described in Assing 2013).

In this same Checklist of Azorean Staphylinidae (Suppl. material 1), we provide some relevant information related to taxonomic or nomenclature changes, splitting it into four columns “synonym”, “different combination”, “misidentification” and “emendation/misspelling”.

Inventory of the Azorean rove-beetles (Insecta, Coleoptera, Staphylinidae)

Leader: Paulo A. V. Borges,

Fieldwork BALA project (Gaspar et al. 2008, Borges et al. 2016): Ana Santos, Álvaro Vitorino, Ana Rodrigues, Anabela Arraiol, Annabella Borges, Artur Serrano, Carla Rego, Carlos Aguiar, Catarina Melo, Clara Gaspar, Emanuel Barcelos, Fernando Pereira, Francisco Dinis, François Rigal, Genage André, Hugo Mas, Isabel R. Amorim, João Amaral, João Moniz, Joaquín Hortal, Kostas Triantis, Lara Dinis, Luís Vieira, Paula Gonçalves, Pedro Cardoso, Sandra Jarroca, Sérvio Ribeiro.

Fieldwork for SLAM - Long term monitoring of Azorean forests using SLAM traps; see list at Costa and Borges (2021).

Fieldwork for LAND-USE project: see list at Cardoso et al. (2009).

Fieldwork for MACDIV: see list at Malumbres-Olarte et al. (2019).

Taxonomists: Michael Schülke, Paulo A. V. Borges, Volker Assing.

The Azores Archipelago extends for 615 km and is located in the North Atlantic Ocean (37-40°N, 25-31°W), about 1600 km from Europe and 2200 km from North America (Fig. 1). The Archipelago is formed by nine main islands and some small islets, all of them of volcanic origin. The islands are divided into three main groups: the western group (Corvo and Flores), the central group (Faial, Pico, Graciosa, São Jorge and Terceira) and the eastern group (São Miguel and Santa Maria). The climate is temperate oceanic, with regular and abundant rainfall, high levels of relative humidity, above 95% on average in native forests and persistent winds, mainly during the winter and autumn seasons. Since Portuguese colonisation in the 15^th century, the landscape of the Azores has been dramatically altered by replacing native forests with forest tree plantations, crops, pastures and urban areas. Currently, the native laurel forest comprises about 5% of the total surface of the Archipelago and has remained only at higher elevations and in inaccessible areas of the islands (Gaspar et al. 2008, Borges et al. 2020).

This inventory of Staphylinidae includes records of several standardised sampling campaigns and non-standardised observations, performed between 1990 and 2015 (Gaspar et al. 2008, Borges et al. 2016). Most of the records (about 96.7%) were collected in standardised sampling campaigns, which included pitfall and beating protocols. Non-standardised records are based on hand-collecting and sifting, as well as cave, colour and malaise traps. Additional non-standard records are based on cave, colour and malaise traps and collecting trips conducted by Volker Assing in Terceira, São Miguel and Santa Maria islands in 2013 and by Andreas Kleeberg in Pico and São Miguel in 2015. Collected samples were sorted and subsequently identified by an expert taxonomist in laboratory.

Species collecting was funded mostly by four projects:

“Reservas Florestais dos Açores: Cartografia e Inventariação dos Artrópodes Endémicos dos Açores” (BALA) (Direcção Regional dos Recursos Florestais, project 17.01-080203) (1999-2003);

“Agriculture, habitat fragmentation, indicator species and conservation of endemic fauna and flora in the Azores – the 2010 Target” (Direcção Regional da Ciência e Tecnologia, DRCT - Postdoc M112/F/014/2007) (2007-2009);

"Predicting extinctions on islands: a multi-scale assessment” (Fundação para a Ciência e Tecnologia- FCT- PTDC/BIA-BEC/100182/2008) (2010-2013);

“Understanding biodiversity dynamics in tropical and subtropical islands as an aid to science based conservation action” (ISLANDBIODIV) (Fundação para a Ciência e Tecnologia , FCT/NETBIOME/0003).

The database management was funded by FEDER (85%) and by Azorean Public funds (15%) through Operational Programme Azores 2020, under the project AZORESBIOPORTAL –PORBIOTA (ACORES-01-0145-FEDER-000072).

The study was conducted in several habitats of eight islands of the Azores Archipelago (Fig. 1): Flores, São Jorge, Pico, Faial, Terceira, Graciosa, São Miguel and Santa Maria Islands. The sampled habitats include exotic, mixed and native forests, intensive and semi-natural pastures, orchards, caves and lava flows (see details in Event Table at Borges et al. 2021a).

This inventory of Staphylinidae (Coleoptera) includes records obtained in several standardised sampling campaigns and by non-standardised methods performed between 1990 and 2015. Most of the records (96.7%) are based on standardised sampling campaigns, which included pitfall and beating protocols. The used methodology is in accordance with BALA protocol - Biodiversity of Arthropods of the Laurissilva of Azores (Gaspar et al. 2008,Borges et al. 2016) implemented during BALA I (1999-2004) and BALA II (2010-2011) projects. Non-standardised records are based on hand-collecting and sifting, as well as cave, colour and malaise traps.

Standardised sampling campaigns included pitfall traps and beating transects. Pitfall trap transect protocols were conducted with 33 cl plastic cups, partially filled with propylene glycol, in the soil (cup rim at surface level) every 5 m. Traps were protected from rain using a plastic plate, placed about 5 cm above surface level and fixed to the ground with wire. The pitfall traps remained active in the field for 14 days. Beating transects were performed by beating the canopy of woody vegetation, using a beating tray. The protocol was conducted when the vegetation was dry. A 5 m wide square was established every 15 m (total of 10 squares per transect). Two woody plant specimens of the most abundant species (up to three species when available) were sampled in each square. For each selected plant, a branch was chosen at random and a beating tray placed beneath it. The tray consisted of a 1 m wide and 60 cm deep cloth inverted pyramid, with a plastic bag at the vertex. Five beatings were made using a stick for each plant individual sampled.

All sorted specimens were identified by a taxonomical expert. Taxonomic nomenclature followed: Schülke and Smetana (2015), Brunke et al. (2021), Yoo et al. (2021).

In terms of species colonisation status, we followed two classifications:

1) For the GBIF database that incoporates occurrence data, we followed the information in the last checklist of Azorean Staphylinidae (Assing 2010). This information is analysed through the main text of this manuscript.

2) However, species classified as "native" by Volker Assing (Assing 2010) have a dubious colonisation origin and were probably inadvertently introduced from the Western Palaearctic. It is highly probable that this happened following human colonisation of the islands and prior to the first reports on Azorean beetles in the 19^th century. Exceptions are Atheta pasadenae and Hypomedon debilicornis, for which the native distribution is unknown.

For that reason, in the current checklist of Azorean Staphylinidae (Suppl. material 1), we now add a column in which we create a new possible tentative categorisation for the colonisation status of the species as follows:

- endemic: species for which we have some evidence that they are true endemics, occurring mostly in native habitats.

- Doubtfully endemic: species whose status is doubtful, based on our current knowledge on the distribution of congeneric species.

- Non-endemic: these include all the previous named as “native” and “introduced” since, in most cases, we currently have no confidence on their status.

- Non-endemic cosmopolitan: these include species with cosmopolitan distribution.

Azores, Portugal (Flores, São Jorge, Pico, Faial, Terceira, Graciosa, São Miguel and Santa Maria).

36.862 and 39.623 Latitude; -31.399 and -24.895 Longitude.

This publication covers the Staphylinidae family (Insecta, Coleoptera).

Entomoteca Dalberto Teixeira Pombo

DTP

Ethanol 96% for posterior DNA analyses

Curator: Paulo A. V. Borges

Creative Commons Public Domain Waiver (CC-Zero)

Inventory of the Azorean rove-beetles (Insecta, Coleoptera, Staphylinidae)

https://www.gbif.org/dataset/81df7e48-1f76-4125-901b-140bd96dfa49

http://ipt.gbif.pt/ipt/resource?r=staphylinidae_occurrences_azores

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The latest list of Azorean rove-beetles from the Azores (Assing 2010) included a total of 115 species and subspecies of Staphylinidae. Since then, a new endemic species was recorded from Azores, Medon varamontis Assing, 2013, known only from São Miguel (see Assing 2013) and the previous family Scydmaenidae (including three Azorean species) was included in the Staphylinidae as a subfamily. In addition, seven species were added in the current study (see above and Table 1). Other additions are explained below.

The catalogue of Palearctic Staphylinidae (Schülke and Smetana 2015) lists several species as recorded from the Azores that are not in the latest list of Azores species (Assing 2010). Only four of these species are now added to our updated list (see Suppl. material 1): Aleochara verna Say, 1833, Atheta aeneicollis (Sharp, 1869), Sepedophilus littoreus (Linnaeus, 1758) and Sepedophilus testaceus (Fabricius, 1793). The decision to add these species is based on the following reasoning:

- Aleochara verna: this species was mentioned previously to Azores by Maus (1998), but without recording the island. Now we record the species for Terceira and Santa Maria (see Table 1).

-Atheta aeneicollis: we found no literature record. The species was added in the 2nd edition of the Staphylinidae catalogue by the Editors (Schülke and Smetana 2015), but the record is not traceable backwards. We have now found many specimens in several islands (see Table 1).

- Sepedophilus littoreus: Schatzmayr (1945) Ponta Delgada (São Miguel), cited by Horion (1967), Hammond (1973) and Herman (2001), also listed in Borges (1990); the presence of this species in the Azores would be plausible.

- Sepedophilus testaceus: old records by Fauvel (1902) and Bernhauer (1940), citing the Crotch (1867) record of S. sericeus, and Méquignon (1942). All these records are doubtful and may possibly be based on misidentification, most probably S. lusitanicus. However, Hammond (1973), who revised the British species and described S. lusitanicus, explicitly wrote that he had seen S. testaceus from the Azores. The species was also listed by Borges (1990).

For 14 species listed in the Palaearctic Catalogue as present in the Azores (Schülke and Smetana 2015), we found no clear support for their addition to the current list of Azorean rove-beetles:

- Atheta maderensis: recorded by Brinck (1977). The record is based on confusion with Atheta pasadenae (see Gusarov 2016).

- Atheta zosterae: recorded by Bernhauer (1940), Méquignon (1942) and Israelson (1984) (misidentification). Later identified as Atheta nigra (Kraatz).

- Astenus gracilis: record most likely based on Crotch 1867and Méquignon (1942); almost certainly misidentification of A. lyonessius.

- Cafius sericeus: recorded by Israelson (1984) as Remus sericeus from Santa Maria. Israelson (1990) stated that this record was based on a misidentification of Remus pruinosus.

- Euplectus afer was recorded by Méquignon (1942) from São Miguel; this record is based on misidentification of E. infirmus.

- Gyrohypnus punctulatus: old records of Crotch (1867) and Méquignon (1942); almost certainly belong to G. fracticornis.

- Leptacinus batychrus: recorded by Fauvel (1897), Fauvel (1902) and Bernhauer (1940) from São Miguel. This is a misidentification of Leptacinus pusillus (Stephens, 1833).

-Philonthus rufipes : was recorded as P. immundus by Bernhauer (1940) from São Miguel and subsequently listed by Borges (1990). P. immundus is a synonym of P. ventralis (Gravenhorst, 1802).

- Sepedophilus marshami: this record is based on Crotch (1867), who recorded Conosomus sericeus Latreille from Flores. This species was later synonymised with S. marshami (Hammond 1973). The record is doubtful and may refer to S. testaceus or S. lusitanicus; most likely it refers to S. lusitanicus.

- For five additional species, no primary records from the Azores were found. Consequently, the respective record from the Azores in the Palearctic Catalogue (Schülke and Smetana 2015) should be deleted: Deleaster dichrous Gravenhorst, 1802, Placusa tachyporoides (Waltl, 1838), Scydmaenus rufus Müller, P.W.J. & Kunze, 1822, Tomoglossa laeta Eppelsheim, 1884 and Tomoglossa luteicornis (Erichson, 1837).

Based on Suppl. material 1, in addition to the old records, several sources of data have contributed to the new records to Azores and individual islands (Fig. 2). Corvo and São Jorge Islands are possibly still not well studied (Fig. 2).

The current list of Azorean rove-beetles has now 136 species (Suppl. material 1). This list includes ten endemic species, but we are confident that only five are really true endemics, the other five being possibly species from other origins, but not yet recorded in the mainland. The five “true endemics” (Atheta floresensis Pace, 2004; Euconnus azoricus Franz, 1969; Medon varamontis Assing, 2013; Notothecta dryochares (Israelson, 1985) and Phloeostiba azorica (Fauvel, 1900)) are commonly found in native forests of Azores and, in particular, N. dryochares is very abundant in the canopies of Azorean endemic trees.

Most of the species assigned to native non-endemic and introduced status in Assing (2010) are mostly of Palaearctic origin and we decided to create an alternative colonisation status categorisation, assiging this species as “non-endemic” and “non-endemic cosmopolitan”. At least 16 species have a worldwide distribution and were classified as “non-endemic cosmopolitan”.

The study of Azorean Staphylinidae is far from complete. We are conducting additional surveys in the Azores (e.g. Costa and Borges 2021, Tsafack et al. 2021) and new records will be soon available covering several habitats.