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 ...

First record of Tropicosa thorelli (Araneae: Lycosidae) attacking the dragonfly Rhionaeschna marchali (Odonata: Aeshnidae)

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First record of Tropicosa thorelli (Araneae: Lycosidae) attacking the dragonfly Rhionaeschna marchali (Odonata: Aeshnidae)

Abstract 

This study records thirteen predation attempts by the wolf spider Tropicosa thorelli (Keyserling) on males of the aeshnid dragonfly Rhionaeschna marchali (Rambur) in a protected area of the Colombian Andes. All events occurred on macrophyte vegetation near the shoreline of the Tominé Reservoir, at the locality of Club Náutico El Muña. For each event, we recorded perch height, time of occurrence, attack duration, and ambient temperature. The observations took place between 11:01 and 11:47 h during the dry season, under temperatures ranging from 21.2 to 23.7 °C. The mean duration of attack events was 12.72 ± 2.41 min. In all cases, the attacks were interrupted by the arrival of R. marchali males, although the mechanisms underlying this behavior remain unclear. These observations suggest that perch characteristics, particularly perch height, may influence the vulnerability of R. marchali males to predation by sit-and-wait spiders. 

Palacino Rodríguez, F., & Palacino-Penagos, D. A. (2026). Primer registro de Tropicosa thorelli (Araneae: Lycosidae) atacando a la libélula Rhionaeschna marchali (Odonata: Aeshnidae). Biota Colombiana, 27, e1300. https://doi.org/10.21068/2539200X.1300