J. Suarez-Sanchez, R. Alatorre-Rosas, H.M. Poggi-Varaldo, and J. Barrera-Cortes. 2012. Effect of the inoculum size on the axenie in vitro production of Steinernema carpocapsae. Cien. Inv. Agr. 39(1): 137-145. The effect of inoculum size on the axenie in vitro production of Steinernema carpocapsae, using a transparent medium with hemoglobin and cholesterol, was studied. Axenie cultivation was performed with fertile eggs of S. carpocapsae (hatching of eggs: 89 +/- 4%), which were obtained by lyses of female nematodes and subsequent incubation. Two important aspects of this work include the use of a completely transparent medium enriched with hemoglobin and cholesterol and the high multiplication factor of the population (MFIP) of 87, which is considered high for in vitro axenie cultures of nematodes. In vivo methods have the advantage of high MFIP, but they also have the disadvantage of the high number and complexity of the operations involved for the purposes of harvesting axenie nematodes. It is assumed that the availability of a high number of nematodes in a transparent medium will further encourage the characterization of new native strains of nematodes.