Seasonal timing of infestation of sweet cherries and non-crop plants by Drosophila suzukii (Diptera: Drosophilidae) in and around sweet cherry orchards of British Columbia, 2010-2013

A vinegar fly, Drosophila suzukii Matsumura (Diptera: Drosophilidae: Drosophilini) (Spottedwing Drosophila) was first detected in the interior of British Columbia in September 2009. Damage to soft fruit and berries from D. suzukii was recorded in three of the past four years; consequently, its presence has led to increased use of insecticides on many crops. We report on the seasonal abundance of D. suzukii in and around sweet cherry (Prunus avium) orchards, as shown: (1) by its presence in twice weekly collections from research orchards of cherries that were assessed using standard tests of fruit colour, pressure, and levels of sugars and titratable acids; (2) by its presence in extensive fruit collections from non-commercial plants near infested orchards. The results will be discussed in the context of understanding the ecology of this invasive insect and of potential strategies for future management or reduction of insecticide use.