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 ...

Cohort splitting is a condition-dependent plastic life-history adaptation to variable environments in the wolf spider, Pardosa agrestis

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By Denali National Park and Preserve - SpiderUploaded by AlbertHerring, Public Domain, https://commons.wikimedia.org/w/index.php?curid=29599032

Cohort splitting is a condition-dependent plastic life-history adaptation to variable environments in the wolf spider, Pardosa agrestis

Developmental plasticity enables organisms to adjust life-history strategies to environmental variability. Cohort splitting—where single cohorts divide into rapid- and slow-developing individuals resulting in facultative bivoltinism—allows us to mitigate environmental unpredictability through plastic life-history decisions. We investigated this phenomenon by documenting developmental patterns under controlled photoperiod regimes in the uniquely cohort-splitting wolf spider Pardosa agrestis and a congeneric species with typical univoltine life cycle. We hypothesized that the basis of cohort splitting is rapid growth that realizes a full growth potential, but is inhibited or uninhibited in a plastic manner. Under experimental conditions, both species possessed the capacity for rapid development but differed in regulatory mechanisms. The cohort splitter species exhibited plasticity based on photoperiod and individual condition, while the non-splitter showed a more uniform response to environmental cues, independent of body state. Sibling status minimally influenced developmental outcomes, indicating low genetic determination. Our results suggest that cohort splitting evolved through differential regulation of an ancestral uninhibited growth pattern. Cohort splitting is a bet-hedging strategy that optimizes fitness in variable environments through plastic developmental inhibition. Conversely, the unconditional inhibition of rapid growth in non-splitters probably reflects adaptation to habitats where predation pressure on late-season generations favours univoltinism.

Ferenc Samu, Dóra Kettinger, Éva Szita, Balázs Kiss; Cohort splitting is a condition-dependent plastic life-history adaptation to variable environments in the wolf spider, Pardosa agrestis. Proc Biol Sci 1 January 2026; 293 (2062): 20252012. https://doi.org/10.1098/rspb.2025.2012