Career
Having worked a few years in trade, he moved to Riga in 1865 and became curator of the Entomological Department of the Riga Museum, and then at the Riga Technical University. In 1873, he was invited by Hermann Burmeister (1807-1892), Director of the Museum of Buenos Aires, to join him in Argentina. As early as 1874, Berg began an expedition to Patagonia to collect specimens for the Museum.
This first collecting trip was followed by others through Argentina, also in Chile and Uruguay.
Apart from a period two years from 1890 to 1892, spent at the Museo Nacional in Montevideo, he was based in Buenos Aires. He replaced Burmeister as the head of the Museum in 1892.
His first specialty was entomology, but he was also dedicated to paleontology and the study of vertebrates.Amongst fis many other achievemants he described Cactoblastis cactorum the cactus moth.