Spodoptera frugiperda (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, Trichogramma pretiosum Riley is the only egg parasitoid used in Integrated Pest Management (IPM) programs regardless of its effectiveness. A search for natural enemies of S. frugiperda 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. Trichogramma atopovirilia Oatman and Platner, an egg parasitoid, and Chelonus insularis Cresson egg-larva parasitoid were recovered from field surveys. Among the natural enemies that preyed on eggs of S. frugiperda, we found mites of the genus Balaustium, and Dermaptera of the genus Doru, both species in great abundance. Laboratory tests were performed to compare the potential parasitism of T. atopovirilia against T. pretiosum. T. atopovirilia obtained 70.14% parasitism while T. pretiosum, 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 T. atopovirilia parasitized a greater number of hosts using two and three parasitoids per pest egg. Then, the use of Trichogramma species needs to be reevaluated in biological control programs against S. frugiperda.

A survey of parasitoids of the pepper weevil (Anthonomus eugenii Cano), one of the most important pests of peppers in North America, was conducted in Mexico as part of a search for biological control agents of this pest. Surveys were conducted in different years on the Pacific and Atlantic Coasts in Mexico. We recovered parasitoid species belonging to 7 genera: Triaspis eugenii Wharton & López-Martínez, Urosigalphus sp., Bracon spp.; Catolaccus hunteri Crawford; Eurytoma spp.; Eupelmus sp.; and Ceratoneura sp. The latter species might be a newly recorded genus for this pest. Catolaccus hunteri, T. eugenii, and Urosigalphus sp. represented 96% of all recovered specimens. Triaspis eugenii was collected only in Nayarit, and Urosigalphus sp. predominated in Oaxaca; both locations are on the Pacific Coast. Catolaccus hunteri was present at every sample site. The biology of the braconids T. eugenii and Urosigalphus sp. would seem to make them best suited for biological control of pepper weevil due to t... Resumen Como parte de una búsqueda de agentes de control biológico del picudo del chile (Anthonomus eugenii Cano), una de las plagas más importantes de este cultivo en Norteamérica, se realizaron colectas de parasitoides de esta plaga en México. Durante varios años se colectó material de las costas del Pacífico y del Atlántico, y se encontraron varias especies pertenecientes a siete géneros: Triaspis eugenii Wharton & López-Martínez, Urosigalphus sp., Bracon spp.; Catolaccus hunteri Crawford; Eurytoma spp.; Eupelmus sp. y Ceratoneura sp. De estos géneros sólo el último se reporta por primera vez para esta plaga. Catolaccus hunteri, T. eugenii, y Urosigalphus sp. representaron 96% del material collectado. Triaspis eugenii se collectó sólo en Nayarit, y Urosigalphus sp. predominó en Oaxaca, ambas localidades en la costa del Pacífico. C. hunteri se encontró en cualquier sitio de colecta. Parece ser que la biología de los bráconidos T. eugenii y Urosigalphus sp. podría ofrecer algunas ventajas para el control...

Bactericera cockerelli (Sulc) (Hemiptera: Triozidae) is one of the most economically important pests of potato, tomato, and peppers in Central America, Mexico, the United States, and New Zealand. Its control is based on the use of insecticides; however, recently, the potential of the eulophid parasitoid Tamarixia triozae (Burks) (Hymenoptera: Eulophidae) for population regulation has been studied. Because T. triozae is likely to be exposed to insecticides on crops, the objective of this study was to explore the compatibility of eight insecticides with this parasitoid. The toxicity and residual activity (persistence) of spirotetramat, spiromesifen, beta-cyfluthrin, pymetrozine, azadirachtin, imidacloprid, abamectin, and spinosad against T. triozae adults were assessed using a method based on the residual contact activity of each insecticide on tomato leaf discs collected from treated plants growing under greenhouse conditions. All eight insecticides were toxic to T. triozae. Following the classification of the International Organization of Biological Control, the most toxic were abamectin and spinosad, which could be placed in toxicity categories 3 and 4, respectively. The least toxic were azadirachtin, pymetrozine, spirotetramat, spiromesifen, imidacloprid, and beta-cyfluthrin, which could be placed in toxicity category 2. In terms of persistence, by day 5, 6, 9, 11, 13, 24, and 41 after application, spirotetramat, azadirachtin, spiromesifen, pymetrozine, imidacloprid, beta-cyfluthrin, abamectin, and spinosad could be considered harmless, that is, placed in toxicity category 1 (<25% mortality of adults). The toxicity and residual activity of some of these insecticides allow them to be considered within integrated pest management programs that include T. triozae.