Interesting species ! It would seem that this evening Monoxenus (Dytiloderus) multispinosus Breuning however Madagascar unlikely! It must be an error of labeling or an importation? For the name of the species I invite you to check because the Monoxenus are not simple to determine except 4 or 5 species. M multispinosus is described from RDC Kivu Kabve and the typus measures 7,5 mm..... I can't tell you more...before you check on your side