Ovipositional preference and life history parameters of Lixus incanescens (Coleoptera: Curculionidae) on selected sugar beet cultivars

Abstract

Ovipositional preference and life history parameters of Lixus incanescens were studied on six sugar beet cultivars: Ardabili, Aras, Persia, Flores, Laetitia and Rosire. In both no-choice and free-choice tests, females of L. incanescens laid fewer eggs on Persia and Laetitia compared with Ardabili, Aras, Flores and Rosire. In performance experiments, the pre-imaginal stages developed slower and survived lower on Persia and Laetitia than on Ardabili, Aras and Flores. The intrinsic rate of natural increase and the population growth rate were lowest on Persia (r_m = 0.126 day⁻¹ and λ = 1.134 day⁻¹) among the tested cultivars. Petiole diameter and length were positively correlated with pre-imaginal survival rate (r² = 0.96 and r² = 0.98, respectively); therefore, thinner and shorter petioles in Persia and Laetitia led to an increased pre-imaginal mortality. These results suggest that Persia and Laetitia express promising traits that can be an integral component of sugar beet breeding for resistance to L. incanescens.

Keywords:

• host preference
• pre-imaginal fitness
• reproductive biology
• sugar beet weevil
• sugar beet cultivars

Acknowledgements

This work was supported by the University of Mohaghegh Ardabili [grant number 653]. Also, we thank Dr Asghari-Zakaria from the Department of Crop Production and Breeding, Mohaghegh Ardabili University and Dr Alizadeh from the Seed and Plant Improvement Institute of Karaj, Iran, for their cooperation in this research.