AR Salvatore1, DC Cabrera1, PG Páez Jerez1,2, JG Hill1,2 and MG Nadra1
1Facultad de Agronomía Zootecnia y Veterinaria, Universidad Nacional de Tucumán, Tucumán, Argentina; analiasalvatore@hotmail.com
2Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Tucumán, ArgentinaDiatraea saccharalis (Ds) is the most important pest of sugarcane (Saccharum hybrids) (So) in Tucumán, Argentina. Weeds are a threat to crop productivity and can act as alternative hosts for pests. Therefore, it is necessary to increase our understanding of Ds‘s preference for oviposition on So, Sorghum halepense (Sh), Urochloa platyphylla (Up), Sicyos polyacanthus (Sp), and Tithonia tubaeformis (Tt). Three oviposition choice assays were conducted. Each assay included three metal cages (1 m³ each), covered with screen, serving as replicates. Within each cage, three 5-L pots were used per plant species. The assays were performed using So (LCP 85-384 variety) and different weed species: Sh (first assay), Sh and Up (second assay), and Tt and Sp (third assay). In each cage, 10 pairs of Ds adults were released for 10 days. The number of egg masses per plant was recorded and the number of eggs per egg mass was determined. In the first assay, the number of Ds masses per plant was higher in So (7.1) than in Sh (4.3). In the second assay, the number of Ds masses was higher in So (20.7) than in Sh (12.2) and Up (11.2). In the third assay, the number of Ds masses was higher in So than in Up and Tt, and no masses were observed in Sp. There were no significant differences among plant species in the number of eggs/egg mass. However, Ds consistently preferred So over all other tested weed species. This study is the first to report Ds laying eggs on Tt, suggesting it could serve as a host. Results contribute to improving integrated pest control strategies, determining the role of weeds associated with the crop.