Potato (Solanum tuberosum) is one of the most important staple food in Brazil, especially for the south region of the country. The southamerican rootworm, Diabrotica speciosa (Col. Chrysomelidae), is the key soil pest attacking stolons and tubers. Its control in fields is based on use of soil insecticides. Damage to potato cultivar and clone tubers by feeding larvae od D. speciosa was evaluated under cage and field conditions. This study was carried out at EMBRAPA-CPACT, in Pelotas, RS (Brazil), during the spring potato season of 1997. Eight potato cultivars and clones for fresh consumption were studied: Baronesa, Cristal, Macaca, Monte Bonito, Trapeira, clone C-1485687, clone C-12263580 and clone CR-1290582, and also eight cultivars and clone for processing: Atlantic, Asterix, Baraka, Bintje, Catucha, Cicklamen, Panda and clone C-15822590. All treatments (cultivars and clone) were replicated four times in a complete random block design. The effect of larval infestation was measured by number of feeding holes in the tuber. In the caged experiment, no significant differences occurred at cultivar and clone groups, either for fresh consumption or processing. However, Panda, Asterix and Atlantic, among processing cultivars and clones, were those with the highest number of southamerican rootworm larvae holes (damage). Among cultivars and clones for fresh consumption, Baronesa and clone C-11261580 had the highest average number of holes. It was concluded that larvae of D. speciosa fed on any potato cultivar or clone tubers. The extent to which this occurs depend on the cultivar or clone itself, although it was not possible to indicate any determined resistance level among those potato cultivars, but only tendencies.
southamerican rootworm; Solanum tuberosum; resistance; screening
