Da Costa-Silva, Vinicius2025-11-202025-11-202025-05-28Da Costa-Silva, V. 2025, 'The first teratological case for the Australian Omorgus Erichson, 1847 species (Coleoptera, Scarabaeoidea, Trogidae)', Contributions to Entomology, vol. 75, no. 1, pp. 235-238, doi : 10.3897/contrib.entomol.75.e148695.2511-6428 (online)10.3897/contrib.entomol.75.e148695http://hdl.handle.net/2263/105395A new case of hemidystrophy in Trogidae is here described and illustrated. The teratological specimen was identified as a male of Omorgus (Omorgus) alternans (MacLeay, 1827), being the first record of a teratological specimen of a trogid from Australia. While teratological cases provide limited taxonomic insights, they offer significant understanding of the environmental influences on insect development. The study emphasizes the importance of documenting such anomalies, contributing to the broader knowledge of developmental biology in insects, particularly within the under-researched Australian Trogidae.enCopyright Vinícius da Costa-Silva. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0).AnomaliesAustraliaHemidystrophyMorphologyOmorginaeTeratologyArticle