Nephus (Nephus) voeltzkowi Weise, 1910

Magro, Alexandra, Almeida, Lúcia M., Churata-Salcedo, Julissa & Hemptinne, Jean-Louis, 2021, New synonym of Nephus (Nephus) voeltzkowi Weise (Coleoptera: Coccinellidae) with comments on the origin of a Neartic population and its possible asexual status, Zootaxa 4949 (1), pp. 198-200 : 198-199

Nephus (Nephus) voeltzkowi Weise, 1910

Nephus (Nephus) voeltzkowi Weise, 1910: 512 (original description); Fürsch 2007: 6 (systematic); Poussereau et al. 2018: 128 (systematic); Magro et al. 2020b: 130–132 (systematic).

Nephus seychellensis Sicard, 1912: 362 (original description). Synonymized by Chazeau et al. 1974: 272.

Scymnus (Nephus) voeltzkowi: Korschefsky 1931: 153 (catalog); Fürsch 1966: 181 (systematic).

Nephus (Nephus) alyssae Golia & Golia, 2014: 1–3 (original description). Syn. nov.

The specimens examined are deposited in the following collections: DZUP - Coleção Entomológica Pe. J. S. Moure, Departamento de Zoologia , Universidade Federal do Paraná, Curitiba, Brazil (Lúcia M. Almeida); FSCA - Florida State Collection of Arthropods, Gainesville, FL, USA (Paul Skelley) .

United States of America: HOLOTYPE (♀), “ Florida, Palm Beach/ County, Hypoluxo/ Hypoluxo Scrub N.A./ November 10, 2009/ Vince Golia/ “sweeping”/ 26.566642, - 80.056759 ”, “ Nephus / sp./ det. R. Gordon 10”, “ HOLOTYPE / Nephus / alyssae/ Golia and Golia” [red label], 1 specimen [ FSCA].

Reunion Island: Specimens from a laboratory rearing (Laboratoire Evolution & Diversité Biologique, Université Toulouse III, France) initiated from field material collected in November 2011 in Manapany-les-Bains , 14 specimens [ DZUP] .

Golia & Golia (2014) in their report of N. alyssae (a synonym of N. voeltzkowi , as shown in the present work) in Florida mention that males were not captured and base their description exclusively on females (10 individuals), which raises the question of the existence of another possible parthenogenetic population of N. voeltzkowi and its colonization of a new continent. An advantage of asexual organisms is their superior colonizing ability, as a single individual can potentially engender a new population. As trade and transport went global, the number of introduced species, namely insects, has considerably increased ( Meurisse et al. 2019). The fact that N. voeltzkowi preys on mealybugs, which are highly common and associated with a large number of plant species, including several important crop plants, might have favoured the ladybird dispersal and settlement in new regions.

Although we cannot exclude more remote sources of colonization, the Azores population of N. voeltzkowi is the most likely origin of the colonizing individuals. Colonization of islands from continental sources is a common event but it has also been shown that islands can be an important source of continental diversity ( Zhang et al. 2017). The Azores relative geographical proximity to the American continent and the fact that it has for centuries acted as one of the crossroads of the North Atlantic Ocean, due to its strategic position, make it a conceivable source of propagules. Furthermore, there is a strong connection between Florida and the Azores because of regular military aircraft exchanges since World War II, and this link has already been pointed as probably at the origin of other species introductions ( Martins & Simões 1985, Schaefer et al. 2011). The atmospheric conditions could also be involved in this introduction as wind has been identified as playing an important role in dispersal ecology, including in intercontinental oceanic dispersal ( De Queiroz 2005). The ability to use thermal uplifts and wind for long range dispersal is common in different insect taxa ( Rota et al. 2016), and has been mentioned for ladybirds ( Siljamo et al. 2020). This dispersal mechanism is particularly important for small insects ( Wainwright et al. 2017), which is the case of Nephus spp.