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 ...

Web placement in grass spiders (Agelenopsis pennsylvanica) is driven more by artificial light at night than by prey

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Web placement in grass spiders (Agelenopsis pennsylvanica) is driven more by artificial light at night than by prey

Light from human-modified landscapes (artificial light at night, or ALAN) can disrupt feeding, rest, reproduction and orientation in many animals. It is considered a contributor to global insect declines, and studies have found that up to one-third of insects attracted to stationary light sources die from exhaustion or predation by sunrise. Many insectivorous vertebrates hunt near artificial light to catch more prey, but few studies have examined whether invertebrate predators similarly exploit artificial light. Here we test how artificial light and prey affect web placement in the grass spider Agelenopsis pennsylvanica (Araneae, Agelenidae). We kept spiders in enclosures that had transparent sides, with a light source outside one corner. In the first experiment, lights either stayed on (light treatment) or off (control) all night, and we compared web placement between groups. Next, we conducted a cue conflict experiment, with light in one corner and prey in a separate unlit corner, and compared web placement between the light and control groups. In the absence of prey, control spider web placement was random while light treatment spiders were more likely to build webs in the lit corner and made their webs significantly closer to the light source. When prey was present, control treatment spiders were more likely to build webs near the prey, while light treatment spiders were still more likely to build webs in the light, and their webs were significantly closer to the light and farther from the prey compared to control spiders. Outdoors, this likely draws them to prey-dense, artificially lit areas. Recent reports, however, suggest that urban insects are evolving reduced flight-to-light behaviour. If spiders continue to prioritize light over prey, artificial light could therefore become an ecological trap for spiders if fewer insects approach the light. This work highlights the complex ways in which human activity may affect communities across temporal scales.

Walsh, W., Winsor, A. M., & Jakob, E. M. (2025). Web placement in grass spiders (Agelenopsis pennsylvanica) is driven more by artificial light at night than by prey. Animal Behaviour, 123365. https://doi.org/10.1016/j.anbehav.2025.123365