More Like this

1. Phylogeny of the orb‐weaving spider family Araneidae (Araneae: Araneoidea)

   https://doi.org/10.1111/cla.12382  

   Scharff, Nikolaj; Coddington, Jonathan A.; Blackledge, Todd A.; Agnarsson, Ingi; Framenau, Volker W.; Szűts, Tamás; Hayashi, Cheryl Y.; Dimitrov, Dimitar (April 2019, Cladistics)
2. The evolutionary history of cribellate orb-weaver capture thread spidroins

   https://doi.org/10.1186/s12862-022-02042-5  

   Correa-Garhwal, Sandra_M; Baker, Richard_H; Clarke, Thomas_H; Ayoub, Nadia_A; Hayashi, Cheryl_Y (July 2022, BMC Ecology and Evolution)

   Abstract BackgroundSpiders have evolved two types of sticky capture threads: one with wet adhesive spun by ecribellate orb-weavers and another with dry adhesive spun by cribellate spiders. The evolutionary history of cribellate capture threads is especially poorly understood. Here, we use genomic approaches to catalog the spider-specific silk gene family (spidroins) for the cribellate orb-weaverUloborus diversus. ResultsWe show that the cribellar spidroin, which forms the puffy fibrils of cribellate threads, has three distinct repeat units, one of which is conserved across cribellate taxa separated by ~ 250 Mya. We also propose candidates for a new silk type, paracribellar spidroins, which connect the puffy fibrils to pseudoflagelliform support lines. Moreover, we describe the complete repeat architecture for the pseudoflagelliform spidroin (Pflag), which contributes to extensibility of pseudoflagelliform axial fibers. ConclusionsOur finding that Pflag is closely related to Flag, supports homology of the support lines of cribellate and ecribellate capture threads. It further suggests an evolutionary phase following gene duplication, in which both Flag and Pflag were incorporated into the axial lines, with subsequent loss of Flag in uloborids, and increase in expression of Flag in ecribellate orb-weavers, explaining the distinct mechanical properties of the axial lines of these two groups. 

   more » « less
3. Water harvesting during orb web recycling

   https://doi.org/10.1636/JoA-S-19-066  

   Opell, Brent D. (December 2020, The Journal of Arachnology)

   null (Ed.)
4. Molecular phylogeny of the orb-weaving spider genus Leucauge and the intergeneric relationships of Leucauginae (Araneae, Tetragnathidae)

   https://doi.org/10.1071/IS21029  

   Ballesteros, Jesús A.; Hormiga, Gustavo (January 2021, Invertebrate Systematics)

   The tetragnathid genus Leucauge includes some of the most common orb-weaving spiders in the tropics. Although some species in this genus have attained relevance as model systems for several aspects of spider biology, our understanding of the generic diversity and evolutionary relationships among the species is poor. In this study we present the first attempt to determine the phylogenetic structure within Leucauge and the relationship of this genus with other genera of Leucauginae. This is based on DNA sequences from the five loci commonly used and Histone H4, used for the first time in spider phylogenetics. We also assess the informativeness of the standard markers and test for base composition biases in the dataset. Our results suggest that Leucauge is not monophyletic since species of the genera Opas, Opadometa, Mecynometa and Alcimosphenus are included within the current circumscription of the genus. Based on a phylogenetic re-circumscription of the genus to fulfil the requirement for monophyly of taxa, Leucauge White, 1841 is deemed to be a senior synonym of the genera Opas Pickard-Cambridge, 1896 revalidated synonymy, Mecynometa Simon, 1894 revalidated synonymy, Opadometa Archer, 1951 new synonymy and Alcimosphenus Simon, 1895 new synonymy. We identify groups of taxa critical for resolving relationships within Leucauginae and describe the limitations of the standard loci for accomplishing these resolutions. 

   more » « less
5. Anchor threads can double the insect flight energy absorbed by spider orb webs

   https://doi.org/10.1242/jeb.245123  

   Han, Sarah I; Alicea-Serrano, Angela M; Blackledge, Todd A (January 2023, Journal of Experimental Biology)

   ABSTRACT To successfully capture flying insect prey, a spider's orb web must withstand the energy of impact without the silk breaking. In this study, we examined the anchor threads: the silk lines that anchor the main capture area of the web to the surrounding environment. These anchor threads can account for a large portion of the web, yet are usually excluded from experiments and simulations. We compared projectile capture and kinetic energy absorption between webs with and without access to anchor threads. Webs with anchor threads captured significantly more projectiles and absorbed significantly more energy than those with constrained anchors. This is likely because the anchor threads increase web compliance, resulting in webs with the ability to catch high-energy flying insects without breaking. Anchor threads are one example of how different types of web architecture expand the range of possible prey capture strategies by enabling the web to withstand greater impacts. 

   more » « less