Southeast Michigan fruit update for July 15, 2011
Apple and blueberry growers need to be on the lookout for maggots, and a spotted wing Drosophila was caught in Allegan County late last week.
In the last two days I have news concerning two pests: one old apple and blueberry pest and the other a new pest found in Michigan for the first time last fall.
The first news concerns apple maggot. Yesterday afternoon (July 14), both Jeanette Yaklin, Genesee area pest management association scout, and I found apple maggots in traps at two different orchards here in east Michigan. Additionally, we each found them on yellow sticky board traps and red sphere traps, which is unusual to catch them in both traps on the same day. Both sites where we caught them received about a half inch of rain that moved through the region on Monday (July 11). This rain event most likely triggered their emergence or catch. Catching apple maggot on yellow board traps is an early indication that they have emerged. Catching them on red sphere traps tells us that they are on the lookout to lays eggs on fruit, which is a key time for control.
This means that apple growers need to be on the lookout for apple maggot catches on traps at their farm, and if found on red sphere traps, make an insecticide application in the next four to seven days to control them. If you are not trapping for apple maggot at your farm, then it is up to you when to make an insecticide application when you think they need to be controlled.
Blueberry maggot has very similar emergence dates as apple maggot, so blueberry growers also need to watch for this pest. Traps need to be checked every few days.
The second pest news that I want to share with you concerns spotted wing Drosophila. This is a new pest of several tree and small fruit crops grown in Michigan. As of Wednesday (July 13), it was confirmed that we caught this pest late last week in Allegan County, which is west of Grand Rapids, Mich. Wednesday afternoon MSU entomologist Rufus Isaacs received confirmation from the USDA-APHIS taxonomist that the specimen caught last week in Allegan County was a male spotted wing Drosophila fly. This was suspected at the time of trap checking, but he wanted to be sure for this first catch of the year. The specific trap is located 50 feet into the woods adjacent to a field that had high catches in fall 2010.
It is important to highlight when delivering this news that we have not detected spotted wing Drosophila in any traps in fruit crops and that many insecticides being used already for control of other insects will be active on spotted wing Drosophila. Monitoring will continue and we will continue to update you as this situation develops.
This first detection of spotted wing Drosophila for 2011 is a wake-up call to make sure traps are well positioned in the shade in the fruit zone, checked regularly, and maintained with fresh apple cider vinegar. Directions on trap design, placement, checking, and also information on management of this insect in blueberries and other fruit crops are all available at MSU IPM’s spotted wing Drosophila website.