Figure 3 from: Nazari V (2021) Taxonomy at Face Value: An assessment of entomological postage stamps as effective teaching aids for science educators. Research Ideas and Outcomes 7: e68056. https://doi.org/10.3897/rio.7.e68056

Figure 3 Shannon's Diversity Index (H) vs. number of entomological stamp issues. Only issuers with highest H and highest number of issued stamps are labeled. Fifty-three countries with an H=0 (A, bottom left) have issued stamps belonging to a single order.