The first spotted wing drosophila adult was found on Tuesday, June 11, in a small field in Burlington County. The trap was placed between the commercial planting and the woods border. This finding, along with the coloring of early varieties, initiates a 7 day insecticide program now required for insect free berries. More on SWD management in the future.
Addendum: Summary of Fax Alert sent subsequent to June 12 post above.
Trapping for SWD began 3 weeks ago using 4 different types of attractants. The first positive trap was collected on 6/10 in Burlington County with a single male. On 6/13, 2 females were picked up at another site near the first one. We expect most other locations to test positive soon. This indicates that flies will be mating and laying eggs on ripening fruit. We assume that the population is low at the present time, but will build up over the next several weeks. This will be reflected in higher trap captures at additional sites. However, we also feel that population pressure must be suppressed over the entire season in order to avoid ‘out of control’ populations that result in infested fruit. Therefore Growers Must Be On A 7 Day Treatment Schedule Using Materials That Are Effective For SWD Control.
Last season this pest was responsible for wormy fruit contamination at many farms including some that were treating for the risk, however the level of contamination was in general proportion to the quality of the spray program. We expect SWD pressure to be at least as strong as last season. Data collected last season also demonstrated that pressure was present in all of our growing areas. Due to the serious risk of SWD we are recommending that ALL farms begin a 7 day treatment program now. Of course several factors may alter the need for a strict “7 day” program such as rainfall and the residual properties of the pesticide. The attached table will provide most of the information about your pesticide options so that you can make the best decisions for your particular situation. Please note that 2 neonicotinoid materials (Assail and Actara) are included in the SWD list. Conflicting research has shown some activity by these materials. These materials have some efficacy, but are weak SWD insecticides. We feel that their place in a SWD program is only early in the SWD season when populations are low, and you may still need something with aphid activity. If you use either Assail or Actara, use them only in the first spray (last week and this week). They are of no practical use for SWD control as the population increases. SWD may prefer shaded areas and therefore may pose greater risk in the sheltered zones of the bush (interior/low). For this reason it is important to achieve the best possible coverage practical for your situation.
