Abstract. Sugar beet weevil, Lixus incanescens Boh., is one of most dangerous pests in sugar beet. Host plant resistance is known as an efficient strategy for pest management. Thus, this study was conducted to investigate the antibiosis resistance induced by zinc element in different cultivars of sugar beet to long snout weevil, L. incanescens. Seeds of eleven commercial monogerm cultivars of sugar beet including Pars, Torbat, Ekbatan, SBSI019, Rizofort, Puma, Dorothea, Brigita, Pecora, Nagano and Jolgeh, were studied. Field was divided to two parts; one part was treated with zinc fertilizer and other part did not treat with fertilizer. Antibiosis parameters were tested. Results clearly did not show that cultivars have antibiosis resistance under non-using fertilizer during 2013 and 2014 years. Rizofort cultivar showed lower susceptibility compared with other cultivars when using zinc fertilizer, because of lower adult weight, female longevity and period length of immature stage during the both years. Thus, Rizofort cultivar was relatively resistant to L. incanescens when using zinc fertilizer during the both years, which can be useful in the development of IPM programs for this insect in sugar beet fields

Abstract. In plants, antixenosis resistance could reduce injury and yield loss; they can produce selection pressures on insect herbivores that lead to pest resistance. Traditionally, sugar beet long snout weevil, Lixus incanescens Boh. (Col.: Curculionidae), is one of the serious pests causing sugar beet losses. In the present study, antixenosis resistance was evaluated in 11 varieties of sugar beet including Pars, Torbat, Ekbatan, SBSI019, Rizofort, Puma, Dorothea, Brigita, Pecora, Nagano and Jolgehin a field trial from 2013 and 2014 years in Qazvin province, Iran. A randomized complete block design with their replications was used. The results showed that in both years, in the first 24 h experiment after release the lowest and highest densities of pest (No. adult/plant) were seen on Pars (2.99) and Dorothea (2.83) varieties, respectively, as opposed the lowest antixenosis resistance were found on Brigita (8.66) and Nagano (8.83) cultivar, whereas on other cultivars showed intermediate values. In Pars, Brigita and Nagano varieties the number of adult weevils (adult/plant) increased rapidly during the first 24 h, but after which there was a decline to the minimum on about the fifth day. The results of data analysis to investigate the mechanism of free choice antixenosis in the years 2013 and 2014 showed that there are no significant differences between experimental blocks and among cultivars tested. As a result, our findings showed that above mention variety can be used in integrated management plans of sugar beet long snout weevil, and with regionally adapted varieties and excellent seed quality we strive for excellent varietal performance in all growing regions of the Iran.