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

Posted by
  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 ...

An integrative study on Mesobuthus rakhshanii (Scorpiones: Buthidae)

Posted by

 


An integrative study on Mesobuthus rakhshanii (Scorpiones: Buthidae)

Abstract

Mesobuthus Vachon, 1950, with 30 described species is widely distributed from the Eastern Mediterranean area to the Eastern Palaearctic. Mesobuthus rakhshanii Barahoei, 2022 is described from the north of Sistan & Baluchestan and southern parts of South Khorasan Provinces. Totally, 213 specimens of M. rakhshanii were collected from the various habitats of these regions during 2021 to 2023. Specimens were studied from morphological, molecular, biological, and ecological point of view. Bayesian inference (BI) analysis based on the COI gene was conducted. Thirty pairs of alive specimens were used for biological study. The maximum entropy model (MaxEnt) was utilized to evaluate the contribution rates of bio-climatic factors and to project suitable habitats for of M. rakhshanii. Unlike other Mesobuthus species, the central median and posterior median carinae of the carapace of M. rakhshanii are not connected. According to the BI, M. rakhshanii forms a sister group with M. navidpouri, indicating that they are the two youngest species within the genus. Mesobuthus mirshamsii was sequenced for the first time and the validity of this species was confirmed. The observed litter size for M. rakhshanii ranged from 22 to 36. Our findings indicate that annual precipitation and the mean temperature of the coldest quarter are the most influential variables affecting the potential distribution of this species. The estimated optimal distribution area for M. rakhshanii is approximately 943,578 km2, representing about 57.25% of Iran's land area. Among the suitable areas, 10.23%, 41.5%, and 5.52% were classified as low, moderate, and high suitability zones, respectively.

Barahoei, H., Madjdzadeh, S.M. & Moeinadini, A. An integrative study on Mesobuthus rakhshanii (Scorpiones: Buthidae). Biologia 81, 112 (2026). https://doi.org/10.1007/s11756-026-02170-z