Edward Mason Janson

worked as a railway clerk,[3] later as an accountant,[4] and became an entomologist in the early 1850s, with two of his sons Edward and Oliver following him into the pursuit.

[5] Edward Mason Janson became a member of the Entomological Society of London in 1869, listed as living in Las Lajas, Chontales, Nicaragua.

[5] Coleoptera material Janson collected in Chontales was examined by Henry Walter Bates and David Sharp for Frederick Godman and Osbert Salvin's project Biologia Centrali-Americana.

[9] William Lucas Distant named the Pentatomidae species Edessa jansoni in 1881 from a specimen collected by Janson in Chontales.

[10] The Staphylinidae species Gyrophaena jansoni was described by David Sharp from a single male example collected by Janson in Chontales.