Spotted wing drosophila (SWD) is an invasive pest that lays its eggs in healthy soft fruit and cherries, rendering them unmarketable. SWD has a very wide host range but there is evidence to suggest that some hosts can slow or prevent the development of SWD eggs.
AHDB commissioned a review aiming to identify plant species that may act as dead-end hosts for the eggs or larvae of SWD to help reduce pest populations as part of an integrated pest management programme.
The review focused on identifying a list of potential dead-end hosts with fruit that: is preferably more attractive to female SWD than crop fruit; prevents the development of eggs to adulthood through toxicity or lack of resources; has a suitable hardiness and growth habit in the UK; and has a fruiting period that overlaps with the crop.
The conclusion of the report indicates several plant species that have potential as dead-end hosts during mid- and late-season soft-fruit periods. In particular, Dyer’s madder, bird cherry, lords and ladies, Portugal laurel, Pokeberry, Scarlet firethorn, Willowleaf cotoneaster and Chenault coralberry are attractive to SWD but do not offer suitable conditions for eggs to develop.
Introducing additional fruiting plants could increase bird populations, which can cause losses and damage to fruit crops. However, birds may help to control SWD by consuming wild berries in which eggs are developing. If crops are routinely netted, planting dead-end hosts that are attractive to birds might be an effective strategy.
Further research is needed to establish how the inclusion of a dead-end host might influence the long-term dynamics of SWD populations. The full report is available to download online — see horticulture.ahdb.org.uk/publications.