Agricultural and Forest Entomology (2016), DOI: 10.1111/afe.12152 Acceptability and suitability of Tuta absoluta eggs from irradiated parents to parasitism by Trichogramma nerudai and Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) Cynthia L. Cagnotti ∗ , Carmen M. Hernández ∗ , Andrea V. Andormo ∗ , Mariana Viscarret ∗ , María Riquelme † , Eduardo N. Botto ∗ and Silvia N. López ∗ ∗ Insectario de Investigaciones para Lucha Biológica-IMYZA-CNIA-INTA, Castelar, Buenos Aires, Argentina and † Department of Zoology, Laboratorio de Zoología Agrícola, Universidad Nacional de Luján, Cruces de rutas 5 y 7, 6700, Luján, Buenos Aires, Argentina Abstract 1 Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is one of the most devastating pests of tomato crops. We studied the acceptability and suitability of eggs laid by irradiated T. absoluta pairs to parasitism by the parasitoids Trichogramma nerudai and Trichogramma pretiosum. 2 Trichogramma absoluta pupae were irradiated with X-radiation (20834 R) and the emerged adults were separated into couples according to the crosses: ♂ U × ♀ U , ♂ I × ♀ U , ♂ U × ♀ I (where ‘U’ is untreated and ‘I’ is irradiated). In a no-choice experiment, 40 eggs from each cross were exposed to a female parasitoid for 24 h. 3 All T. absoluta eggs were accepted for oviposition by T. nerudai and were suitable for its development. However, eggs from irradiated females were signifcantly less parasitized than those from untreated females. Trichogramma pretiosum showed low parasitism on eggs from all crosses. In a choice experiment, both T. nerudai and T. pretiosum showed no differences in the parasitism of eggs from irradiated (n = 40) and non-irradiated female moths (n = 40). 4 These results indicate that eggs laid by irradiated parents were acceptable for oviposition and suitable for the development of these parasitoids, and also support the idea that the inherited sterility technique could be used in an integrated approach with egg parasitoids to control T. absoluta. Keywords Biological control, egg parasitoid, inherited sterility, natural enemies, tomato leafminer, X rays. Introduction The tomato leafminer Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a neotropical insect native to South America originally described in Peru (Desneux et al., 2010). From the early 1980s onward, it has been recorded as one of the most devastating pests of tomato in Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Paraguay, Peru, Uruguay and Venezuela (Barrientos et al., 1998; Botto et al., 2000; Estay, 2000; Desneux et al., 2010, 2011). This pest was frst reported in eastern Spain in 2006 (Desneux et al., 2011) and has spread rapidly throughout the Mediterranean Basin and other parts of Europe (Desneux et al., 2011). Tuta absoluta can cause up to 80 – 100% yield losses in tomato crops in invaded areas and it is currently considered Correspondence: Cynthia Lorena Cagnotti. Tel.: +54 11 4450 1876; fax: +54 11 4450 0805; e-mail: cagnotti.cynthia@inta.gob.ar a threat to both greenhouse and open-feld tomato production. Control of tomato leafminer infestations is a serious problem because the larvae are protected inside the leaf mesophyll. In South America, repeated insecticide treatments are used to control T. absoluta (Desneux et al., 2010; Guedes & Picanço, 2011). However, this practice has led to the development of T. absoluta individuals resistant to a wide variety of chemi- cal active ingredients (Lietti et al., 2005; Reyes et al., 2011). Furthermore, the extensive use of insecticides can negatively affect the performance of benefcial insects through lethal and sublethal effects (Croft, 1990; Desneux et al., 2007). The use of genotypes of resistant tomato plants has been studied as an alternative to chemical control (de Oliveira et al., 2009, 2012; Castro Antonio et al., 2011). Other environmentally friendly control strategies against the tomato leafminer have been proposed, such as biological control and mass trapping using pheromone traps (de Oliveira et al., 2008; Desneux et al., © 2016 The Royal Entomological Society