| Summary: | <i>Spodoptera frugiperda</i> (Smith) is the main maize pest in America and was recently detected as an invasive pest in some countries in Asia and Africa. Among its natural enemies presented in Mexico, <i>Trichogramma pretiosum</i> Riley is the only egg parasitoid used in Integrated Pest Management (IPM) programs regardless of its effectiveness. A search for natural enemies of <i>S. frugiperda</i> was then carried out to determine whether this parasitoid has been established, and to detect native egg parasitoids or predators associated with this pest. The sentinel technique (egg masses) was used, and then placed in maize and sorghum fields in the state of Guanajuato, Mexico. <i>Trichogramma atopovirilia</i> Oatman and Platner, an egg parasitoid, and <i>Chelonus insularis</i> Cresson egg-larva parasitoid were recovered from field surveys. Among the natural enemies that preyed on eggs of <i>S. frugiperda</i>, we found mites of the genus <i>Balaustium</i>, and Dermaptera of the genus <i>Doru</i>, both species in great abundance. Laboratory tests were performed to compare the potential parasitism of <i>T. atopovirilia</i> against <i>T. pretiosum</i>. <i>T. atopovirilia</i> obtained 70.14% parasitism while <i>T. pretiosum</i>, 29.23%. In field cages, three doses of the parasitoids were tested. Total parasitism did not exceed 8% in any of the two species, but <i>T. atopovirilia</i> parasitized a greater number of hosts using two and three parasitoids per pest egg. Then, the use of <i>Trichogramma</i> species needs to be reevaluated in biological control programs against <i>S. frugiperda</i>.
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