In vitro evaluation of venom extracts of Sphecid wasps against phytopathogens of horticultural crops and mass spectrometric profiling of venom peptide components

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  In vitro evaluation of venom extracts of Sphecid wasps against phytopathogens of horticultural crops and mass spectrometric profiling of venom peptide components Abstract As the shortcomings of synthetic chemicals become gradually evident, the dynamics of pest and disease management in modern agriculture are progressively shifting towards environmentally safer alternatives. Biopesticides, such as peptide-based approaches offer attractive alternatives, although their potential remains yet to be fully explored. In this exploratory study, crude venom extracts from previously unexplored Hymenopteran sphecid wasps ( Chalybion bengalense , Sceliphron madraspatanum , Ammophila atriceps and Sphex argentatus ) were evaluated for their antimicrobial activity against selected plant pathogens. The venom extracts demonstrated prominent antibacterial activity lacking antifungal activity. Among the wasps, C . bengalense exhibited the most significant antibacterial activity against Gram-negati...

Elevated Temperatures Disrupt Wolbachia-Induced Feminisation and Reshape Microbial Community Dynamics Across Generations in a Spider Host

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Elevated Temperatures Disrupt Wolbachia-Induced Feminisation and Reshape Microbial Community Dynamics Across Generations in a Spider Host

ABSTRACT

Longitudinal microbial interactions within a host are challenging to study, leading to a focus on constructed microbial communities in vitro settings. Here, we take advantage of a naturally defined microbial community within a spider host to study how elevated temperatures influence microbial dynamics and phenotypes across host generations. The spider Mermessus fradeorum hosts up to five endosymbionts, including a Wolbachia strain, W1, which induces feminisation, causing genetic males to develop as phenotypic females, skewing sex ratios and promoting symbiont spread. Despite this, Wolbachia 1 persists at intermediate frequencies in wild populations. We hypothesised that elevated temperatures might reduce penetration of the feminisation phenotype, potentially by altering symbiont dynamics and maternal transmission. We exposed spiderlings co-infected with Wolbachia 1 to elevated temperatures for one generation and measured feminisation rate, symbiont transmission, and titre across three generations. Feminisation was unaffected in the exposed (F1) generation but declined in subsequent generations (F2, F3) that were not directly exposed. This multigenerational effect was linked to shifts in symbiont community dynamics: low feminisation coincided with high abundance of one symbiont, Rickettsiella, a decline in Wolbachia 1 transmission, and complete loss of another symbiont, Tisiphia. Our findings demonstrate how environmental history shapes the evolutionary stability of microbial communities and their induced phenotype in their natural host.

Mackevicius-Dubickaja, V., White, J. A., Williams, E. E., Klement, E., Gottlieb, Y., & Doremus, M. R. (2026). Elevated Temperatures Disrupt Wolbachia-Induced Feminisation and Reshape Microbial Community Dynamics Across Generations in a Spider Host. Molecular Ecology, 35(9), e70371. https://doi.org/10.1111/mec.70371