The firethorn (Pyracantha coccinea), a promising dead-end trap plant for the biological control of the spotted-wing Drosophila (Drosophila suzukii)

Abstract

The spotted-wing Drosophila, Drosophila suzukii(Matsumura, 1931) (Diptera: Drosophilidae), is an invasive pest which causes important damage to fruit crops. Despite significant economic and environmental harm, no satisfactory means of control have been found yet. One interesting option for the biological control of D. suzukii is the use of dead-end trap plants. These are attractive plant species that divert the pest away from infesting the main crop while being lethal for its offspring. Here we explored the efficiency of the firethornPyracantha coccineaas a dead-end trap plant forD. suzukii. We conducted experiments both in controlled laboratory conditions and in growhouses, offering conditions closer to the reality of the field. Our results show that the fruits ofP. coccineaare highly attractive toD. suzukiiwhile being invariably deadly for its offspring. The infestation rate of strawberries, a very attractive fruit commonly infested byD. suzukii, was reduced by 40% when firethorn fruits were present in the set-up. We also monitored the survival ofD. suzukiioffspring inP. coccineafruits and observed that mortality occurred before pupation, mainly during the 2ndlarval instar, along with a darkening of the larvae’s cuticle. Our results demonstrate the potential ofP. coccineain the biological control ofD. suzukii. Indeed, planting firethorn near fruit crops could offer an efficient, durable and low-maintenance solution to reduce the damages caused byD. suzukii.