The entomopathogenic fungus Purpureocillium sp. strain UdeA0106 was isolated in soil from a farm belonging to the Universidad de Antioquia. This fungus has shown potential in vitro and under greenhouse conditions to control symphylans (Scutigerella sp.) , a pest that attacks chrysanthemum crops, whose control has been achieved with the use of some insecticides, which temporarily reduce populations but without the desired efficiency throughout the cultivation cycle. Currently the Purpureocillium sp. strain UdeA0106 is applied in combination with another biocontrol fungi, fungicides and insecticides in the integrated pest management systems (IPM) for chrysanthemum crops (eastern Antioquia); however, the ecological aspects related to the compatibility of the fungus Purpureocillium sp. strain UdeA0106 and the control strategies are unknown. The goals of the present study were to evaluate the in vitro antagonism of Purpureocillium sp. strain UdeA0106, with the biocontroller Paecilomyces lilacinus (Samson 1974), Beauveria bassiana (Vuill. 1912), Metarhizium anisopliae (Sorokīn 1883) and Trichoderma viride (Pers. 1794), using the dual plates method, and to study the effect of plant protection products applied regularly in flower crops on Purpureocillium sp. strain UdeA0106, under laboratory conditions. The results Recibido: abril 2013; aceptado: marzo 2014. 1 Grupo Bioma (Biocontrol y Microbiologia Ambiental). Instituto de Biologia, Universidad de Antioquia. Medellin (Antioquia), Colombia. 2 Docente, Grupo de Investigacion Bioma (Biocontrol y Microbiologia Ambiental). Instituto de Biologia, Universidad de Antioquia. Medellin (Antioquia), Colombia. 3 Docente, Grupo de Investigacion Grica, Facultad de Ciencias Agrarias, Universidad de Antioquia. Medellin (Antioquia), Colombia. Correos electronicos: 4 ; 5 ; 6 .