Technical Abstract: Fopius arisanus (Sonan) is an important parasitoid of Tephritid fruit flies for at least two reasons. First, it is the one of only three opine parasitoids known to infect the host during the egg stage1. Second, it has a wide range of potential fruit fly hosts. Perhaps due to its life history, F. arisanus has been a successfully used as a biological control agent against fruit flies in multiple tropical regions. One impediment to the wide use of F. arisanus for fruit fly control is that it is difficult to establish a stable laboratory colony. Despite this difficulty, in the 1990s USDA researchers developed a reliable method to maintain laboratory populations of F. arisanus. There is significant current interest in F. arisanus biology, especially regarding its ability to colonize a wide variety of Tephritid hosts; interest is especially driven by the alarming spread of Bactrocera fruit fly pests to new continents in the last decade. Further research on and additional deployments of this species as a biological control agent will benefit from optimizations and improvements to rearing methods. In this protocol and associated video article we describe an optimized method for rearing F. arisanus based on a previously described approach. The method we describe here allows rearing of in a small scale without the use of fruit, using materials available in tropical regions around the world and with relatively low manual labor requirements.