Integrated Pest Management against aphids in strawberry crops:4 years of experience in France

Abstract: Since 2005, strawberry crops have been investigated by Koppert in collaboration withresearch stations and growers, as the demand for developing IPM strategies in strawberry cropshas been growing. After developing an IPM strategy against thrips, which was the main pest instrawberry crops, aphids became the major problem for French growers very quickly. Theobjectives of the studies carried out since 2007 were, initially to make an inventory of the aphidspecies, to investigate the behaviour of aphids on strawberry plants, and to find a damagethreshold for each species. Thereafter, to develop and adapt a biocontrol strategy with the use ofChrysoperla spp., which is one of the predators that is efficient at low temperatures. The predatorwas tested at two different release rates: 1 larva/plant and 5 larvae/plant released preventivelyaccording to the growth stage of the strawberry plants. The results lead to the establishment of ageneral decision-making program for interventions with Chrysoperla spp. Some parasitoids, likeEphedrus cerasicola, were also started to be evaluated. In 2009, new parasitoids were tested(Aphidius ervi, A. colemani, Aphelinus abdominalis and Praon volucre) and integrated into thestrategy with Chrysoperla spp. The objective was to develop an economically feasible strategywith Chrysoperla spp. by testing lower doses and different release frequencies. In 2010, a newmix of parasitoids was tested: Aphidius ervi, A. colemani, A. matricariae, Aphelinus abdominalis,Ephedrus cerasicola and Praon volucre. The aim was to see if some of these parasitoids areactive at low temperature and to know if there are better candidates than the ones tested so far tocontrol aphids, especially Rhodobium porosum and Acyrtosiphon malvae rogersii which remainthe most problematic in the South-West of France, one of the largest production areas.