But it turns out that individual butterfly species are sometimes shockingly difficult to tell apart. Cue museum collections and genetic analysis—a biological dream team. Using more than 1,000 samples from collections around the globe, they discovered nine previously unidentified butterfly species in the Thereus genus. Plate illustrating the forewing androconia of 16 male butterflies in the Thereus genena species group, revealing distinctive scent-scale patterns used to differentiate the species. The Natural History Museum hosts “five million butterfly specimens which makes up about 6% of the entire collection,” Blanca concluded.