The "truth" about the false widow

 

This paper looks at the origins and spread of Steatoda nobilis, some dodgy arachnology from the Revd. Octavius Pickard-Cambridge, and concludes that the reason for its rapid range expansion is ... unknown (but it's not climate change). 

Steatoda nobilis, a false widow on the rise: a synthesis of past and current distribution trends. (2019) NeoBiota, (42). https://doi.org/10.3897/neobiota.42.31582

Abstract: 

The Noble False Widow, Steatoda nobilis (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.

 

Bionic Spider Silk

High-strength and ultra-tough whole spider silk fibers spun from transgenic silkworms. Matter: 6, 10, P3661-3683, (2023). 

Summary: "To advance ecological civilization, developing sustainable, eco-friendly high-strength and ultra-tough alternatives to non-sustainable synthetic fibers, such as nylon, is crucial. This necessitates a deeply scientific understanding of the fundamental determinants of fiber strength and toughness, as well as overcoming engineering challenges for cost-effective, large-scale production of high-performance silk fibers. Inspired by the mechanical properties of polyamide fibers, including nylon and Kevlar, we employed CRISPR-Cas9-mediated gene editing to successfully synthesize whole polyamide spider silk fibers from transgenic silkworms. These fibers exhibited impressive tensile strength (1,299 MPa) and toughness (319 MJ/m3), surpassing Kevlar’s toughness 6-fold. Thus, they offer promising potential as sustainable alternatives to synthetic commercial fibers. Furthermore, our research provides valuable insights into the fundamental essence of fiber toughness and tensile strength, challenging the conventional notion that these properties are contradictory. These findings have significant implications for guiding the production of synthetic commercial fibers that simultaneously possess high strength and ultra-toughness."

https://doi.org/10.1016/j.matt.2023.08.013