1. Introduction Plant diversity in agroecosystems can play a key role by supporting communities of natural predators to pests for conservational biological control. The South American tomato leafminer Tuta absoluta (Meyrick) is a prevalent pest of tomato crops in Argentina, and it is almost exclusively controlled by chemical pesticides. Objectives The purpose of this study The purpose of this study is to maximize the action of natural enemies of T. absoluta already present in agroecosystems with the goal of reducing pesticide use. The specific objectives The specific objectives were: 1) to assess the host plant range of T. absoluta 2) to determine the host range of Pseudapanteles dignus (Muesebeck) (Hymenoptera: Braconidae), a major T. absoluta parasitoid in tomato 3) to explore the larval parasitoid complex of T. absoluta and other leafminer species Materials and Methods -Study site: -Study site: NE Buenos Aires Province, Argentina (34°55'49"S, 58°8'13"W). -Field surveys: -Field surveys: monthly sampling, from January 2013 through November 2014. -Plant species: -Plant species: Solanaceous, cropped –excluding tomato- and spontaneous species, selected by a centrifugal phylogenetic approach. - Laboratory procedure: - Laboratory procedure: plants, leafminer hosts and parasitoids collected were identified and numbers of each were recorded. Parasitoid complex associated to Tuta absoluta (Lepidoptera: Gelechiidae) and other leafminers in cultivated and non-cultivated Solanaceae, in Argentina 1 CEPAVE (CONICET-UNLP), La Plata, Argentina; 2 School of Life Sciences, Arizona State University, Tempe, Arizona, USA; 3 Centro de Investigaciones Entomológicas de Córdoba/Instituto Multidisciplinario de Biología Vegetal (IMBIV) Córdoba, Argentina. Salas Gervassio, N.G. 1, Luna, M.G. 1, Lee, S. 2, Salvo, A. 3, & Sánchez, N.E. 1 Figure 1. Plant species surveyed, CULTIVATED: a) Capsicum annuum; b) Nicotiana tabacum; c) Solanum melongena; NON-CULTIVATED: d) Solanum nigrum; e) Solanum sp.; f) Nicotiana glauca; g) Salpichroa origanifolia; h) Solanum sissymbriifolium; i) Datura ferox; j) Brugmansia arborea; k) Nicotiana longiflora. a b i f g d e c k h j Figure 2. T. absoluta and P. dignus registered in cropped and non cropped Solanaceous species, during 2013 and 2014. Results Larval parasitoid complex of T. absoluta and other gelechiid species: Conclusion and Discussion  T. absoluta develops continuously on S. melongena, N. glauca and S. nigrum. Herbaceous S. origanifolia and S. sissymbrifolium temporarily support T. absoluta populations.  Parasitism of T. absoluta by P. dignus occurs in S. melongena, N. glauca, S. nigrum and S. sissymbrifolium.  A complex of 5 gelechiid species attack solanaceous plants in the region studied, supporting 16 parasitoid species. Table 1. Plants, SMEL: S. melongena, NGLA: N. glauca, SNIG: S. nigrum, SORI: S. origanifolia, SSIS: S. sissymbrifolium. Parasitoid species in parentheses: Agat: Agathidinae, Camp: Campopleginae, Eulo: Eulophidae, Horm: Horminae, Micr: Microgastrinae. SMELNGLASNIGSORISSIS T. absoluta (P. dignus, Dineulophus phthorimaeae, Camp1,Ichn1) T. absoluta (P. dignus, D. phthorimaeae, Horm1,2, Micr3, Agat1,3, Orgilus sp., Bracon sp.) Gelechiidae 1 T. absoluta (P. dignus, Copidosoma sp., Eulo, Micr1, Agat2) T. absoluta (Micr2) T. absoluta (P. dignus) Tuta sp. Gelechiidae 2 Phthorimaea operculella T. absoluta host-plant range and P. dignus host range: Figure 3. T. absoluta abundance and percentage of parasitized larvae by P. dignus.