W504: Biology and Management of Spotted Wing Drosophila in Small and Stone Fruits
Statement of Issues and JustificationStatement of Issue and Justification: Spotted Wing Drosophila (Drosophila suzukii, SWD) has been recorded on multiple crops in California during both 2008 and 2009. During 2009 SWD was also recorded in British Columbia, California, Oregon and Washington. During both seasons, producers of stone (cherries and peaches) and small fruits (blackberries, blueberries, raspberries and strawberries) have been hard hit by SWD infestations (Steck et al. 2009, Dreves & Walton 2009). Due to the rapid spread and uniqueness of this pest in the USA, very little information is available on SWD biology, monitoring and management. In California, current reports on management and monitoring is provided (UC IPM 2009, Bolda 2009), but limited. Work by Uchino & Kanto-Tosan (2005) and Kimura 2004 show that SWD has tremendous reproductive potential and can have multiple generations per season. In temperate regions, low temperatures are the most restrictive factor for overwintering survival of Drosophila populations (Izquierdo, 1991). No information is however available for local strains of SWD. Local information is needed on physiological traits such as overwintering capability, spring emergence, seasonal abundance, susceptible fruit stages and detailed control strategies. This insect is a direct pest of all mentioned fruits and attack ripening fruit as opposed to overripe fruit that is attacked by the majority of other Drosophila species.
Direct crop losses of high value crops are of concern to these commodities. Statewide reports of 25% loss of fresh cherries were recorded in California. Several California, Oregon and Washington berry growers have reported 100% crop loss crop losses in late ripening small fruits during 2009. Growers in Oregon have reported 100% crop losses on fresh peaches. This pest clearly has hit growers of multiple commodities hard, resulting in substantial economic losses. Information on integrated and sustainable system-wide control strategies are essential in order to facilitate financial survival of growers.
Back to Top