Hi Kevin, I have seen such spots on numerous dung beetles. Nor sure what they are, but I doubt they simply dirt sticking to the specimens. They are attached firmly to the cuticle and in some specimens they must be attached when the specimen is still teneral as they leave a depression on the cuticle when detached. I am also interested to find out about what they are. Cheers, François De : Scarab Beetle Taxonomy Discussion List [mailto:[log in to unmask]] De la part de Floate, Kevin Envoyé : 11 octobre 2017 15:14 À : [log in to unmask] Objet : Query RE: mysterious yellow spots on Onthophagus taurus Hi All: My colleague, Wes Watson, has a project with Onthophagus taurus. A number of the adult beetles he's recovering are speckled with yellow spots. Closer examination reveals what appears to be yeast(?) in the spots. Have others made a similar observations on beetles? Photos are attached. Any clue as to what these are? If you can help Wes out, I know he would appreciate it. Please contact Wes directly at [log in to unmask]<mailto:[log in to unmask]> Thanks, Kevin Kevin Floate, Research Scientist Insect Biocontrol | Lutte biologique aux insectes Lethbridge Research Centre | Centre de recherches de Lethbridge Agriculture and Agri-Food Canada | Agriculture et Agroalimentaire Canada 5403 - 1st Avenue South, P.O. Box 3000 | 5403 - 1ère Avenue Sud, C.P. 3000 Lethbridge, Alberta, CANADA T1J 4B1 Email | Adresse courriel: [log in to unmask]<mailto:[log in to unmask]> Telephone | Téléphone: 403-317-2242 Facsimile | Télécopieur: 403-382-3156 Teletypewriter | Téléimprimeur: 613-773-2600 Government of Canada | Gouvernement du Canada http://sites.google.com/site/dungins/homepage Dr. Kevin Floate, Editor-in-Chief The Canadian Entomologist<http://journals.cambridge.org/action/displayJournal?jid=tce>