Blueberry cultivars differ in susceptibility to the elephant weevil, Orthorhinus cylindrirostris (Coleoptera: Curculionidae)

Accumulated damage from elephant weevil larvae, O. cylindrirostris (F.) (Coleoptera: Curculionidae), reduces blueberry yield and shortens the productive lifespan of blueberry plants by several years. Selective breeding to develop pest-resistant blueberry cultivars is a possible control option but the relationship between O. cylindrirostris populations, plant damage and blueberry yield has not been described. A field survey of 17 blueberry cultivars was conducted on a commercial farm to measure O. cylindrirostris populations (emergence holes and adult numbers) and yield from plants of different ages (2-12 years). Blueberry plants clearly accumulated damage over time, i.e. older plants tended to have more O. cylindrirostris emergence holes than younger plants. All cultivars received some level of O. cylindrirostris attack but this did not always lead to yield losses. Newer cultivars that have been in production since 2000 were less susceptible to O. cylindrirostris than older cultivars. Highly susceptible cultivars need to be removed from commercial blueberry farms to reduce O. cylindrirostris populations. There is potential for selective breeding to increase plant resistance to O. cylindrirostris if the specific resistance mechanisms can be identified in blueberry.