Spider venom peptides Ht1a and Gg1a are toxic to honeybee parasite Varroa destructor by topical application

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  Spider venom peptides Ht1a and Gg1a are toxic to honeybee parasite Varroa destructor by topical application Abstract Global food supply strongly depends on honeybee pollination services, which are threatened by insecticides and pests such as parasitic Varroa destructor mites. Chemical varroacides/acaricides are hampered by resistance development, necessitating the development of sustainable and environmentally friendly alternatives, with arthropod venom peptides being considered promising sources of acaricidal toxins. With only a few acaricidal venom peptides being reported, we performed a systematic topical screening of 50 arthropod venoms against V. destructor , with 78% of the venoms causing 100% mortality after 24 h. Deconvolution of the venoms from the Tasmanian cave spider Hickmania troglodytes and the Giant Japanese funnel-web spider Gigathele gigas led to identification of the varroacidal peptides Ht1a and Gg1a. Topical application of Ht1a and Gg1a reduced varroa mite ...

Riparian spiders make pyriform silk attachment discs that stick better when wet than those of terrestrial spiders

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Riparian spiders make pyriform silk attachment discs that stick better when wet than those of terrestrial spiders

Adhesion in wet conditions presents significant challenges due to the disruptive effects of water on interfacial bonding, spreading and curing. Many organisms have evolved adhesives that adhere strongly in damp or submerged environments. However, the pyriform silk attachment discs of the terrestrial western black widow spider lose ∼8 times their adhesive strength when wet. Here, we tested the hypothesis that riparian species of spiders have evolved attachment discs that are resistant to the adverse effects of water on adhesion. We compared adhesion of attachment discs from three terrestrial spiders from relatively dry habitats with those of three riparian spider species when discs were loaded under both dry and wet conditions. Failure modes shifted from dragline breakage in dry conditions to adhesive failure in wet conditions across all species, highlighting the impact of water on interfacial bonding. However, riparian species’ attachment discs maintained adhesive force when wet while terrestrial species experienced ∼50% reduction in peak force and work of adhesion in wet conditions. These findings suggest that riparian spider silks have evolved specializations that maintain adhesive performance of pyriform attachment discs in wet environments, offering insights into bioinspired design for water-resistant adhesives.

Bernd F. Steklis, Todd A. Blackledge; Riparian spiders make pyriform silk attachment discs that stick better when wet than those of terrestrial spiders. J Exp Biol 15 November 2025; 228 (22): jeb250902. doi: https://doi.org/10.1242/jeb.250902