Reticulum is another one of the constellations invented by Abbe Nicholas Louis de Lacaille who mapped the stars of the southern hemisphere from the Cape of Good Hope in the years from 1751 to 1753.
The translation of Reticulum as "The Net" is somewhat misleading. The constellation does not represent anything like a fishing net or a butterfly net. What it represents is the gridwork of calibration lines in the eyepiece of an optical instrument, that is, a reticle.
De La Caille gave the constellation the full name of Reticulum Rhomboidalis and apparently meant the constellation to commemorate the reticle in the eyepiece of the telescope with which he measured star positions during his expedition to the Cape of Good Hope.