Attract-and-kill as a new strategy for the management of the potato tuber mothsPhthorimaea operculella(Zeller) andSymmetrischema tangolias(Gyen) in potato: evaluation of its efficacy under potato field and storage conditions

Abstract

Attract-and-kill composed of pure sex pheromones of the potato tuber moths Phthorimaea operculella (Zeller) and Symmetrischema tangolias (Gyen) and the insecticide cyfluthrin resulted in 100% mortality of males under controlled laboratory conditions. The aim of the present study was to investigate the efficacy of this strategy in different potato agroecologies as well as under simulated potato storage conditions. Attract-and-kill was highly effective at reducing male flight activity and significantly reduced daily moth catches in pheromone-baited water traps (by 51.8-99.9%) in comparison with untreated plots. This largely depended on the field size, the attract-and-kill droplet size and the density applied per hectare. Highest efficacy, which was independent of pest density, was achieved when attract-and-kill was applied on larger potato fields using a droplet density of 2500 source points ha(-1) at a droplet size of 100 µL. Consequently, pest infestation on vegetative plant parts as well as on tubers was significantly reduced (by up to 90%) in comparison with untreated controls. Under simulated storage conditions with a high number of females and males released periodically, an efficacy of 84.1 and 87.2% was achieved in reducing tuber infestation by P. operculella and S. tangolias respectively. Attract-and-kill is very effective in controlling the two potato tuber moth species under both field and storage conditions; it is a new, attractive and (for storage conditions) low-cost method that can be easily integrated in potato pest management programmes, especially in small-scale agricultural systems of the tropics and subtropics.