The development of standard protocols for artificial rearing is essential for a suitable production of insects. The eggs of the wheat moth Sitotroga cerealella Olivier are used to rear the oophagous parasitoids of the genus Trichogramma. In the present work we evaluated the effect of three wheat types (pan, candeal, Klein Tauro) on biological parameters of the moth adults and the parasitoid Trichogramma nerudai (Pintureau & Gerding). Also, the content of proteins, the carbohydrates and the moisture of each wheat type were analyzed. There were significant differences in the emergence, fertility, development time and sexual ratio of moths among wheat classes. No significant differences were found in the emergence, fertility and sex ratio of the parasitoid developed on eggs of moths coming from different classes of wheat. The analysis of amino acids and lipids, the biology of the moth and certain tendency observed in the fecundity of the parasitoid suggest that the most suitable wheat types for rearing these two insects are pan and candeal.

La estandarización de protocolos para la cría artificial es esencial para lograr una producción de insectos adecuada en calidad y cantidad. Los huevos de Sitotroga cerealella Olivier se utilizan para la cría de parasitoides del género Trichogramma. En el presente trabajo se evaluó el efecto de tres tipos de trigo (pan, candeal, Klein Tauro) sobre parámetros biológicos de la polilla y del parasitoide oófago Trichogramma nerudai (Pintureau & Gerding). La cría de la polilla se realizó sobre cada tipo de trigo y sobre los huevos obtenidos se evaluaron aspectos biológicos del parasitoide. Las clases de trigo se diferenciaron en la calidad de sus proteínas, lípidos y contenido de humedad. Para los distintas tipos de trigo se encontraron diferencias significativas en el porcentaje de emergencia, la fecundidad, el tiempo de desarrollo y la proporción sexual de las polillas. No existieron diferencias significativas en el porcentaje de emergencia, fecundidad y proporción sexual de parasitoides criados sobre huevos de polillas procedentes de diferentes clases de trigo. El análisis de aminoácidos y lípidos, los resultados sobre la biología de la polilla y cierta tendencia observada en la fecundidad del parasitoide, sugieren que los trigos más adecuados para la cría son pan y candeal.

Trialeurodes vaporariorum es una importante plaga asociada al tomate cuyo control se basa en el uso de agroquimicos. El objetivo de este trabajo fue evaluar la integracion del control quimico y biologico de T. vaporariorum mediante el uso del parasitoide Encarsia formosa (Hymenoptera: Aphelinidae) (CB-CQ), y comparar esta estrategia de manejo con una basada en el uso exclusivo y racional de insecticidas (CQ). Los experimentos se realizaron en invernaderos experimentales entre agosto y diciembre de 2005. Se revisaron semanalmente 12 plantas por invernadero, registrando la cantidad de adultos en las dos hojas superiores y el numero de ninfas IV normales y parasitadas en un foliolo del tercio medio de la planta. El nivel de accion para realizar tratamientos de control quimico en todos los invernaderos fue el registro de ≥ 8 ninfas en promedio por foliolo y para liberar al parasitoide en el tratamiento CB-CQ fue el de ≥1 ninfa en todo el invernaculo. Se observaron tres picos de adultos y dos picos de ninfas que superaron el nivel de accion para la aplicacion de agroquimicos. En el tratamiento CQ se realizaron cinco aplicaciones de insecticidas en tanto en el tratamiento CB-CQ se realizaron ocho liberaciones de E. formosa y dos aplicaciones con un producto mas inocuo para el parasitoide. El parasitismo por E. formosa en el tratamiento CQ-CB alcanzo un 75% hacia el final del estudio. Los resultados indican que el uso del parasitoide puede contribuir al control de la plaga, disminuyendo la cantidad de aplicaciones de insecticidas.

Trialeurodes vaporariorum is an important pest associated with tomato crops, whose control is based on the use of agrochemicals. The objective of this work was to evaluate the integration of chemical and biological control of T. vaporariorum through the use of the parasitoid Encarsia formosa (Hymenoptera: Aphelinidae) (CB-CQ), and to compare this management strategy to one based on the exclusive use of insecticide applications (CQ). Experiments were carried out in experimental greenhouses between August and December, 2005. Twelve plants per greenhouse were examined weekly, recording the number of adults on the two upper leaves and the number of normal and parasitized fourth instar nymphs on a leaflet of the middle third of the plant. The action threshold to conduct chemical control treatments in all greenhouses was the recording of ≥8 nymphs on average per leaflet, and to release the parasitoid in the CB-CQ treatment it was ≥1 nymph per greenhouse. Three peaks of adults and two peaks of nymphs were observed, surpassing the action threshold for application of agrochemicals. In treatment CQ, five insecticide applications were made, while in treatment CB-CQ eight releases of E. formosa and two applications with a product less harmful to the parasitoid were made. Parasitism by E. formosa in treatment CQ-CB reached 75% toward the end of the study. The results indicate that the use of this parasitoid can contribute to control of the pest, decreasing the number of insecticide applications.

The tomato moth, Tuta absoluta Meyrick, is one of the most important tomato pests in South America. In Argentina, management strategies include only chemical control. In this work, the parasitoid wasp Trichogrammatoidea bactrae Nagaraja was evaluated as a potential natural enemy against this pest. Biological and population parameters were estimated by developing a life table under laboratory conditions at 25 ± 1ºC, 14:10 photoperiod and 60 ± 10% RH. Three cohorts of 26-30 T. bactrae females each were placed with one of the three following treatments: 1 - Sitotroga cerealella (Olivier) eggs on a piece of cardboard; 2 - S. cerealella eggs on a piece of tomato leaf, and 3- T. absoluta eggs on a piece on tomato leaf. The following parameters were estimated for each cohort: survival (egg to adult), longevity, fecundity and oviposition period of females, sex proportion of the F1, net rate of reproduction (Ro), mean generation time (T) and intrinsic rate of population increase (r m). Survival of the T. bactrae immatures was higher than 90% on both, S. cerealella and T. absoluta eggs. The female survival curves corresponded to type III and showed no significant differences among treatments. The three cohorts did not show significant differences between sex ratio, female longevity, oviposition period, fecundity and the population parameters studied. These results indicate that T. bactrae would be a potential biological control agent of T. absoluta.