In December 1934 the arrival of one of the best known and most appreciated collections of the Calderini Museum, both from an aesthetic point of view and above all from a scientific point of view: the entomological collection of Dr. Roberto Haas, dedicated exclusively to the order of the Beetles and made up of nearly 30,000 specimens, grouped in 150 boxes. There is little information about the author of the collection: Germanic by birth, Dr. Haas, before his transfer to Brazil at the end of the First World War, was a guest in Geneva with a Valsesian friend and left him the aforementioned entomological collection, which it therefore became part of the Calderinian collections when the contacts between the two ceased to exist. The last scientific reorganization of the collection, with cataloging and restatement of the specimens, dates back to the sixties of the twentieth century and was carried out in collaboration with the Civic Museum of Natural History in Milan.