Predator and Parasitoid Interaction with Aphid-Resistant Potatoes to Reduce Aphid Densities: A Two-Year Field Study

Abstract

Mechanical exclusion experiments demonstrated that Naturally occurring aphid predators (primarily Coccinellidae and Chrysopidae) and parasitoids (primarily Aphidiidae) produced >65% reduction in aphid densitieson Solanum tuberosum L. x S. berthaultii Hawkes, F₃ hybrids bearing different densities of glandular trichomes. In the absence of natural enemies, aphid resistance was directly related to trichome densities. A similar relationship was observed when predator sand parasitoids were present, but aphid densities were lower on all potato clones. These results indicate that biological control and plant resistance are compatible and complementary tactics in integrated pest management on potatoes. Because of the action of predators and parasitoids, potato clones bearing moderate rather than high densities of glandular pubescence should be considered for long-term pest management.