The alien synanthropic Salticidae in Brazil (Araneae)

ABSTRACT Salticidae is the most diverse family of Araneae and in Brazil, there are 667 species. Among these species, five are synanthropic exotics: Plexippus paykulli (Audouin, 1826), Hasarius adansoni (Audouin, 1826), Menemerus bivittatus (Dufour, 1831), M. nigli Wesołowska & Freudenschuss, 2012 and Thyene coccineovittata (Simon, 1886). To understand the current distribution of these species in Brazil, seven collections of 643 lots were examined from seven Brazilian zoological collections. The synanthropic exotic species with the highest records were Plexippus paykulli, Menemerus bivittatus, and Hasarius adansoni, generally collected and associated with human dwellings and buildings. They are present in all regions (North, Northeast, Midwest, and South macro-regions), with the largest region, in all regions of the country in 22 states and 98 municipalities, followed by Hasarius adansoni in 17 states and 88 municipalities, Menemerus bivittatus in 19 states and 68 municipalities. Menemerus nigli and Thyene coccineovittata are from recent introductions that occurred in the city of Rio de Janeiro, Rio de Janeiro, Brazil.

Urban environments went through anthropological processes with a high demand for natural resources and inadequate discard of tailings (Hogan et al., 2001), creating urban niches with conditions for some arachnids to establish their populations (Robinson, 2005).Among these are the spiders (Araneae), with their ability to occupy different niches (Pickett et al., 2001;Swanson et al., 2009), occupying mainly the peridomicile of the residences (e.g.walls, gardens, other constructions) (Robinson, 2005).
In Brazil, there is still no national survey of Brazilian synanthropic spiders, but Indicatti & Brescovit (2008) reported 92 species of urban spiders in the city of São Paulo.Some other authors contributed with surveys of populations of synanthropic species in the states of Pará and Maranhão (Rodrigues et al., 2017), Bahia (Brazil et al., 2005), and in several other northeastern states (Carvalho et al., 2014).
One of the easily found families is the Salticidae (jumping spiders) (Mondal et al., 2020), spiders of these are small, not exceeding 10 mm in size, with eight eyes, arranged in ocular formula 4-2-2, being the two medium eyes anterior, larger than the others (Mondal et al., 2020;Platnick, 2020).It is the most diverse family within Araneae, having more than 6,395 species distributed worldwide (World Spider Catalog, 2022).Of these, 670 species occur in Brazil, being the largest diversity hotspot in the world, and followed by China with 574 species and Australia, with 507 species (Metzner, 2020).Some occupations of urban niches occur through the accidental or intentional introduction of alien species (Robinson, 2005), under favorable conditions, these instructions can affect arthropod assemblages since spiders are efficient predators (Nyffeler, 2000;Nentwig, 2015).
Records in the World.Menemerus bivittatus is an African species introduced by anthropic action in southern Europe, China, Taiwan, Japan, Australia, Pacific islands, and the Americas (World Spider Catalog, 2022).
The alien synanthropic Salticidae in Brazil (Araneae) Diagnosis, Menemerus nigli differs from M. bivittatus by presenting a white marginal stripe, however thinner and does not extend to the abdomen (Figs 13,14).Males have a marked curvature of the embolus in the palp (Figs 15,16) and females have a pyramid-shaped epigynum, with a shorter anterior atrium, and a short median septum (Figs 17,18).
Records in the World.Menemerus nigli is a newly described species originally from Pakistan; its distribution extends to India and Thailand (World Spider Catalog, 2022), and was recently registered in Brazil (Mariante & Hill, 2020) (Fig. 34).
The alien synanthropic Salticidae in Brazil (Araneae)
The distribution of synanthropic exotic Salticidae.Three of the five species have a wide distribution in Brazil, where Plexippus paykulli occurs in 22 of the 27 federative units, being absent in Alagoas, Amapá, Distrito Federal, Pernambuco, and Rondônia (Fig. 30).
Menemerus nigli and Thyene coccineovittata in Brazil were only recorded in the city of Rio de Janeiro (Fig. 34).
Currently, Brazil has only five species of exotic Salticidae.The introduction of M. bivittatus and H. adansoni it has first recorded in the year 1924 in Blumenau, Santa Catarina; P. paykulli was registered for the first time in the year 1934 in Porto Alegre, Rio Grande do Sul.
Menemerus bivittatus has 95 records associated with human constructions (mainly on walls) and 16 related with urban vegetation (mainly on tree trunks), corroborating the existing literature (Wesołowska, 1999;Penney & Gabriel, 2009;Mondal et al., 2020).However, the higher occurrence in anthropized regions may indicate a preference for urban niches in regions where the species was introduced.Beyond these, five records are associated with the hive of bees in São Paulo, São Paulo, and  Hasarius adansoni has the greater diversity of occupied niches, with 108 records in human constructions and 16 records related with urban vegetation, of this, only one in a tree trunk; this information corroborates the existing literature, where the species is commonly reported in the peridomicile of residences (Clark & Benoit, 1977;Mondal et al., 2020).
Menemerus nigli was only found in anthropized areas, but the presence of another species of the same genus allows us to speculate that it will have the same distribution profile and occupy the same niches.
The records of T. coccineovittata in urban vegetation may indicate that this Salticidae prefers environments such as gardens, urban parks, woods, and forests.If the species starts to occupy natural niches, it could pose a threat to arthropod populations and their ecosystem relationships.More studies are need on its invasive potential and its impact on ecosystems.
Menemerus nigli and Thyene coccineovittata have a restricted distribution in the city of Rio de Janeiro -Rio de Janeiro, probably due to the recent introductions of the species.Plexippus paykulli, M. bivittatus, and Hasarius adansoni are widely distributed throughout Brazil, and the regions where no records were found are likely related to the lack of collections.
Although M. bivittatus occurs in urban áreas and probably does not impact most other species, further studies are needed to understand whether the species may be impacting native bee populations.Already P. paykulli and H. adansoni do not affect native species and they occur together with synanthropic native Salticidae in urban niches such as Megafreya sutrix (Holmberg, 1875) and Frigga quintensis (Tullgren, 1905).
In addition, in the Americas, there are species of exotic Menemerus and may result in new introductions M. brachygnathus (Thorell, 1887), M. taeniatus (L.Koch, 1867), M. semilimbatus (Hahn, 1829).Although the literature indicates two species of Hasarius for Brazil, Hasarius lisei needs a taxonomic review, since its structures do not match the diagnosis of the genus.
the one record is related with the hive of Trypoxylon sp.(wasp) in the region of Botucatu, São Paulo.
Tab. I. Number of records per observation of the collection site of the most representative species of synantropic exotic Salticidae.