Homotypic assortative mating is consistent across temporal scales in the spider Mecynogea lemniscata (Araneidae)

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Homotypic assortative mating is consistent across temporal scales in the spider Mecynogea lemniscata (Araneidae) Abstract Identifying patterns of size-assortative mating (SAM) indicates the direction of genetic changes in a population. A reliable method for estimating it in a population is to measure mate assortments within and between breeding seasons¸ as well as describing size variation of males and females between temporal scales to avoid Simpson’s paradox. We assessed sexual size dimorphism, the effects of ontogeny, size differences within each sex, the consistency of SAM within and between seasons, and male mate choice in the spider  Mecynogea lemniscata . We collected mating pairs in a  Eucalyptus  plantation across two breeding seasons and in four periods of the second season. We measured body mass and carapace width of spiders. Males matured earlier than females and guarded subadult partners. Although adults were larger and heavier than subadults, ontogeny did no...

Note on the introduced Asian mud-dauber wasp Sceliphron curvatum (F. Smith, 1870) and its prey in Belgium

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Note on the introduced Asian mud-dauber wasp Sceliphron curvatum (F. Smith, 1870) and its prey in Belgium

Abstract
This note documents the first observations of the prey of Sceliphron curvatum (F. Smith, 1870) (Hymenoptera: Sphecidae) in Belgium, recorded in the municipality of Jette (Brussels-Capital Region). The analysis of the paralyzed prey (n = 39) revealed the presence of nine spider species belonging to five families: Anyphaenidae, Araneidae, Philodromidae, Salticidae and Thomisidae. The family Araneidae dominates the trophic spectrum, represented mainly by juveniles of Araneus diadematus (Clerck, 1757). Two relatively rare species or species with a restricted regional distribution were identified: Macaroeris nidicolens (Walckenaer, 1802) (Salticidae) and Philodromus buxi (Simon, 1884) (Philodromidae). These data indicate opportunistic exploitation of spiders associated with upper (vegetation) layers and adaptation to anthropized habitats. The lack of marked trophic specialization in S. curvatum suggests a low risk of significant impact on native spider populations in Belgium. However, further quantitative studies are needed to assess potential competitive interactions with native arthropod predators. 

Henrard, Arnaud & Drumont, Hugo & Drumont, Alain. (2025). Note on the introduced Asian mud-dauber wasp Sceliphron curvatum (F. Smith, 1870) and its prey in Belgium. 40. Journal of the Belgian Arachnological Society Volume 40 (1) 2025