Suitability of Amaranthaceae and Polygonaceae species as food source for the sugar beet weevil Asproparthenis punctiventris Germar

Abstract

This study explores the food plant spectrum of the sugar beet weevil (Asproparthenis punctiventris Germar; Coleoptera: Curculionidae), one of the most important pests of sugar beet (Beta vulgaris subsp. vulgaris Altissima group). It examines the potential of various weeds and other plants to maintain populations of A. punctiventris adults and larvae outside sugar beet fields. To this end, leaf consumption of females and males on twelve Amaranthaceae and six Polygonaceae species was compared over a 24-h period in a laboratory environment. Both sexes consumed the greatest amount of leaf mass from Beta spp. and on average about a third less from Atriplex spp., indicating that these plants have the highest nutritional value for A. punctiventris. Weevils consumed between 30 and 60% of the amount of A. retroflexus and Chenopodium spp. than they fed on sugar beet leaves. Like Spinacia oleracea (Amaranthaceae), plant species of the Polygonaceae family were hardly or not at all fed on. Mated females generally consumed more leaf mass than unmated, especially from Chenopodium spp. and A. retroflexus, i.e. plants with low feeding value. Experiments with potted plants revealed that the most and heaviest 4th instar larvae developed on sugar beet, while fewer individuals with lesser weight were found on B. vulgaris subsp. maritima and A. hortensis. Very few larvae were able to develop on C. album, and none on A. retroflexus. To prevent promotion of pest population, special attention should be paid to the control of weeds from the Amaranthaceae family in sugar beet growing areas.