Dutch entomologist. Toxopeus attended the University of Amsterdam and began a career as a teacher in 1923. After gaining his doctoral degree in 1930 he travelled back to his homeland, Java, where he served in positions at a number of schools before being appointed Lecturer in Zoology at the University of Indonesia in 1946. He moved to Bandoeng in 1949 as a professor. Although primarily interested in insects, Toxopeus also collected plants on the Royal Dutch Geographical and Treub Society expedition to the western Moluccas (Buru, Maluku) in 1921-1922, and in Sumatra in 1934. He also joined the Third Archbold Expedition to Dutch New Guinea in 1938-1939, but did not collect plants on this trip.

Sources:
M.J. van Steenis Kruseman, "Cyclopedia of Collectors", Flora Malesiana, online edn:
http://www.nationaalherbarium.nl/FMCollectors/T/ToxopeusLJ.htm.