Steatoda nobilis, a false widow on the rise: a synthesis of past and current distribution trends

Abstract

The Noble False Widow, Steatodanobilis (Thorell, 1875) (Araneae, Theridiidae), is, due to its relatively large size and potential medical importance, one of the most notable invasive spider species worldwide. Probably originating from the Canary Islands and Madeira, the species is well established in Western Europe and large parts of the Mediterranean area and has spread recently into California and South America, while Central European populations were not known until 2011. We report on long-time observations that reveal that at least two flourishing populations in Germany (Cologne) have been present for over five years, while in Ecuador one population has been observed between 2014 and 2018 and several other records were made in other parts of the country. Data obtained from the British Spider Recording Scheme demonstrate that the species moved significantly northwards since the report of the first populations in the very South of England, after several decades of relative stasis. The sudden northward expansion highly correlates with a massive rise in press coverage of the species. In the Americas, S.nobilis is currently known from four countries (USA, Chile, Ecuador, Colombia), and available DNA barcoding data obtained for specimens from this area suggest that multiple introductions occurred within each country. Using ecological niche modeling, we identified suitable climate regions for the species and discuss possible reasons for its current spread. We propose that seaside cities and villages with a temperate oceanic or Mediterranean climate are especially favourable potential habitats for S.nobilis and will face the highest colonization pressure in the future, while tropical upland regions with temperate climates are also vulnerable to invasion by S.nobilis.

Venomics Approach Reveals a High Proportion of Lactrodectus-Like Toxins in the Venom of the Noble False Widow Spider Steatoda nobilis

“…In recent years, another spider from the widow family (Latrodectinae), the noble false widow Steatoda nobilis (Thorell, 1875), which looks superficially like a true black widow ( Figure 1) has extended its range globally and may represent a potential risk to native ecosystems and human health [8][9][10][11]. S. nobilis is now regarded as potentially being one of the world's most invasive species of spiders [8].…”

“…In recent years, another spider from the widow family (Latrodectinae), the noble false widow Steatoda nobilis (Thorell, 1875), which looks superficially like a true black widow ( Figure 1) has extended its range globally and may represent a potential risk to native ecosystems and human health [8][9][10][11]. S. nobilis is now regarded as potentially being one of the world's most invasive species of spiders [8]. This species originates from the Macaronesian archipelago [12] and has established populations across Western Europe including Ireland and Great Britain [8,[12][13][14][15], through Western Asia (Turkey and Iran) [16,17], and North and South America [10,[18][19][20].…”

“…S. nobilis is now regarded as potentially being one of the world's most invasive species of spiders [8]. This species originates from the Macaronesian archipelago [12] and has established populations across Western Europe including Ireland and Great Britain [8,[12][13][14][15], through Western Asia (Turkey and Iran) [16,17], and North and South America [10,[18][19][20]. S. nobilis has an exceptional longevity (up to five years) [21], a fast reproductive rate, is cold tolerant with year-round activity [12], and has a fast-acting venom that allows it to subdue a broad range of invertebrate and even vertebrate In Europe and South America, Steatoda nobilis has been involved in envenomations [9][10][11] commonly resulting in prolonged, moderate to intense pain, swelling and erythema.…”

“…S. nobilis has an exceptional longevity (up to five years) [ 21 ], a fast reproductive rate, is cold tolerant with year-round activity [ 12 ], and has a fast-acting venom that allows it to subdue a broad range of invertebrate and even vertebrate prey [ 12 , 13 ]. Outside of its native range, S. nobilis has been demonstrated to have a negative impact on native species [ 8 , 12 , 13 , 22 ]. In temperate regions, S. nobilis has a typical synanthropic lifestyle which brings it in close contact with humans [ 12 ].…”

Synanthropic spiders, including the global invasive noble false widow Steatoda nobilis, are reservoirs for medically important and antibiotic resistant bacteria

“…The noble false widow spider, Steatoda nobilis, has expanded its range across Europe 43 , (including Ireland 12 , 44 , 45 and the UK 43 ), through Western Asia 46 , 47 , and the Americas 43 , 48 – 53 . This species is increasingly linked to medically significant bites to humans, especially in Ireland and the UK 29 , 48 , 50 , 53 , 54 .…”