7.22.13 Spotted Wing Drosophila (SWD)

More SWD has been captured in the coastal growing area. Nine flies were captured this past week in a Warren field and continued single SWD detections have been found in Union and Lincolnville. However, despite the number of fields where this pest has been captured in traps there are still several fields in this area that have not detected SWD. The first capture Downeast was in Marshfield last week, but as of today, no other occurrences have been reported. It appears that recent applications of insecticide to control blueberry maggot fly might be negatively affecting SWD as fields that we had found SWD in earlier and that were sprayed have had few if any subsequent captures. This is just a guess because it could also be that the hot weather we had last week was detrimental to SWD as well. It has been reported that SWD does not tolerate extremely high temperatures.

Last week we collected fruit samples from coastal and central Maine and inspected the fruit for SWD larvae infestation using the “saltwater crush test”. The fields sampled were fields that have had SWD reported in them for at least a week. Thus far, we have not found any SWD larvae in fruit, but we will sample more fields this week.

At this point, we recommend that you continue to be vigilant and monitor. Be prepared to protect your crop if SWD trap captures occur. Again, hopefully, a significant amount of harvest can occur prior to SWD captures in many fields.

NOTE: SWD updates will only be made when we have trap captures.