Jaramillo, C. M and A. Saenz. 2013. Control of Delia platura (Diptera: Anthomyiidae) with Steinernema sp. strain JCL027 (Rhabditida: Steinernematidae) in commercial spinach. Nematropica 43:97-104. We evaluated the level of control of Delia platura (Meigen, 1826) (Diptera: Anthomyiidae) by Steinernema sp. strain JCL027 in commercial spinach production. Three crop phenological stages were evaluated separately: germination, development, and harvest. At the beginning of each stage, applications were made as follows: 0, 5 x 10 2 , 1 x 10 3 , 2 x 10 3 , 4 x 10 3 and 8 x 10 3 JIs/plant and a chemical control (Monitor). Application of Steinernema sp. strain JCL027 during germination, development, and harvest, reduced crop damages by 40 to 50% at the 8 x 10 3 IJs/plant dose, compared to chemical control. Regarding the persistence in field, 20% of infective juveniles can be recovered starting from the dose of 2x10 3 IJs / plant. Steinernema sp. strain JCL027 is an alternative to control the seed fly and can be integrated into management strategies for spinach in Colombia.