Tarbiat Modares University Journal of Agricultural Science and Technology 1680-7073 Articles in Press 2026 07 19 Differential suitability of sugar beet cultivars for the beet armyworm (Spodoptera exigua): Insights from life-table analysis 29003 EN Mostafa Maroufpoor Department of Plant Protection, Agriculture Faculty, University of Kurdistan, Sanandaj, Iran 0000-0001-6677-7267 Amin Sadeghi Differential suitability of sugar beet cultivars for the beet armyworm (Spodoptera exigua): insights from life-table analysis 0000-0001-6048-3532 Raul Narciso C Guedes Departamento de Entomologia Universidade Federal de Viçosa, Viçosa, MG 36570-000 Brazil. 0000-0001-6229-7549 Kovsar Janeh 1. Department of Plant Protection, Agriculture Faculty, University of Kurdistan, Sanandaj, Iran. 0009-0002-9566-301X Heydar Azizi 2. Agriculture and Natural Resources Research Center of West Azerbaijan, Urmia, Iran 0000-0001-6677-7267 Journal Article 2026 05 10 The beet armyworm, <strong><em>Spodoptera exigua</em></strong><em> </em>(Hübner) (Lepidoptera: Noctuidae), is a major pest of sugar beet (<em>Beta </em><strong><em>vulgaris</em></strong><em> </em>L.) worldwide, causing substantial quantitative and qualitative yield losses. In this study, we examined the life history and demographic parameters <strong>of</strong><strong> </strong><strong><em>S. exigua</em></strong><em> </em>on four commercial sugar beet cultivars ('Arta', 'Karta', 'Nika', and 'Rubina') under controlled laboratory <strong>conditions.</strong> Population parameters were estimated using the age-stage, two-sex life table approach. The egg incubation period did not differ significantly among cultivars (approximately 2.00 days; <em>P</em> > 0.05). <strong>However, the total preadult developmental time (egg to adult emergence) differed significantly among cultivars and was shortest on 'Karta' and longest on 'Arta'</strong>. Fecundity varied markedly among cultivars, reaching its highest value on 'Arta' (382.97 eggs/female) and lowest on 'Nika' (132.37 eggs/female). A similar pattern was observed for key demographic parameters:<strong> </strong>the net reproductive rate (<em>R</em>₀) ranges from 56.72 offspring/individual on 'Nika' to 169.67 offspring/individual on 'Arta'. The intrinsic rate of increase (<em>r</em>) varied significantly among cultivars, ranging from 0.152 day⁻¹ on 'Nika' to 0.209 day⁻¹ on 'Arta'. Taken together, these results suggest that cultivar 'Nika' is less suitable for population growth of <em>S. exigua</em> under laboratory conditions, whereas 'Arta' appears more favorable. Slower population growth on cultivars such as 'Nika' may contribute to reduced pest pressure, although this would need to be confirmed under field conditions. Accordingly, 'Nika' could be considered a potentially useful component within IPM programs, rather than a fully resistant cultivar per se. https://jast.modares.ac.ir/article_29003_7a1e01c1f482effc90f8e7d0e2581aff.pdf