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.

Olfactory Responses of Asproparthenis punctiventris Germar to Leaf Odours of Amaranthaceae Plants

“…vulgaris. Larvae can develop on the roots of A. hortensis and C. album, albeit in smaller numbers than on sugar beets, but not on the roots of A. retroflexus [23]. While A. punctiventris males, but not females, were attracted to the leaf odour of A. hortensis in our olfactometer experiments, no response was observed when the weevils were tested with leaf odours of C. album or A. retroflexus.…”

“…In a leaf consumption comparison of food plants from the family Amaranthaceae, unmated female and male sugar beet weevils were found to consume the largest amounts of leaf mass from sugar beets and chard of all plants tested. In addition, the most and heaviest fourth instar larvae developed on sugar beets [23]. Whether A. punctiventris females also prefer B. vulgaris to other plants for oviposition remains to be investigated.…”

“…vulgaris, such as C. album or A. retroflexus [5], might be only accepted upon contact, and acceptance may vary between females and males. In bioassays in petri dishes, Dittmann et al [23] offered leaves of the latter plants to the weevils, which accepted them as food as they came into contact with them. Again, sensilla on the antennae, mouthparts, and other body parts of this Curculionid species still need to be investigated.…”

“…Phytophagous insects usually use plant volatiles to locate suitable hosts for feeding or oviposition [21], which is particularly true for species with an oligophagous feeding pattern [22], such as A. punctiventris. Dittmann et al [23] showed that the adults feed mainly on B. vulgaris subsp. vulgaris and few other Amaranthaceae species, such as the garden orache Atriplex hortensis, the fat hen Chenopodium album, and the common amaranth Amaranthus retroflexus.…”