A Remarkable Discovery: Exploring a Rare Eresus and Spider Wasp Interaction

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  Photo Credit: © Antonino Rametta . All photographs are used with permission. No part of these images may be reproduced, distributed, or used in any form without the prior written permission of the photographer. A Remarkable Discovery: Exploring a Rare Eresus and Spider Wasp Interaction One of the most rewarding aspects of maintaining Arácnido Taxonomy is hearing from naturalists and photographers around the world who take the time to share their discoveries. Every so often, an email arrives that immediately captures your attention. Not because it claims to rewrite what we know about biodiversity, but because it documents something that very few people have the opportunity to witness. Recently, I was contacted by a naturalist in Sicily who shared a series of exceptionally high-quality photographs of a female ladybird spider ( Eresus ) during what appeared to be an interaction with a spider wasp. Along with the images came a simple question: "Could this be scientifically import...

Fluctuating asymmetry in spider-hunting wasps as a possible indicator of stress in Brazilian Atlantic Forest landscapes

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Fluctuating asymmetry in spider-hunting wasps as a possible indicator of stress in Brazilian Atlantic Forest landscapes

Abstract

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  1. Habitat loss and land-use intensification are among the major drivers of biodiversity decline worldwide, leading to measurable effects on organismal morphology, physiology, behaviour and developmental stability that cascade to survival, reproduction and population dynamics.
  2. Using fluctuating asymmetry (FA), we analysed whether Trypoxylon (Trypargilum) opacum Brèthes, 1914 (Hymenoptera: Crabronidae), one of the species found in the Brazilian Atlantic Forest, reflects the level of stress experienced by certain spider-hunting wasps. In addition, female wing size was analysed across 18 landscapes with varying characteristics between 2012 and 2024.
  3. The landscape metrics used in this analysis included forest, agricultural and pasture cover. FA was estimated using Procrustes scores, while wing size was measured by centroid size (CS).
  4. Simple regression analyses revealed a positive relationship between FA and agricultural cover, while CS was positively associated with forest cover and negatively related to agricultural cover (p < 0.05). These results suggest that populations in more intensively farmed landscapes experience greater developmental instability.
  5. Habitat simplification and environmental stressors induced by intensive agricultural management in agricultural landscapes further impair insect developmental homeostasis, increasing the likelihood of reduced developmental stability and increased FA.
  6. Although T. opacum is considered a species related to open habitats, our results indicate that forested areas play an important role in promoting larger wing size, likely by providing key prey resources and foraging opportunities.
Ribeiro, M. C., & Tunes Buschini, M. L. Fluctuating asymmetry in spider-hunting wasps as a possible indicator of stress in Brazilian Atlantic Forest landscapesAssimetria flutuante em vespas caçadoras de aranhas como possível indicador de estresse em paisagens da Mata Atlântica brasileira. Ecological Entomology. https://doi.org/10.1111/een.70062