Boxwood leaf miner stage - Ask Extension
Hello I currently believe I have leafminer on my boxwood shrubs I’m wondering what the best course of action would be at this point In time as I’m...
Knowledgebase
Boxwood leaf miner stage #871728
Asked June 05, 2024, 1:44 PM EDT
Hello I currently believe I have leafminer on my boxwood shrubs I’m wondering what the best course of action would be at this point In time as I’m not to sure what stage this pest is in. I wanted to apply a product like imacloprid but wasn’t sure if I was to late now. What would you reccomend based on pictures and treatment. Also what would be the best plans for next year to stay ahead of this pest they have done quite a bit of damage to my boxwoods
Wayne County Michigan
Expert Response
Hi Ryan, Thank you for your inquiry.
The link below from Clemson University will give you excellent information about boxwood leafminer and its control. Scroll down to "Insects and Related Pests," and you will find the info on Boxwood Leafminers.
https://hgic.clemson.edu/factsheet/boxwood-diseases-insect-pests/
It's a good idea to confirm that it is really leafminer that is affecting your plant. You can open a few leaves and see if any larvae are still present. Here is additional information on how to treat leafminers.
https://www.canr.msu.edu/news/boxwood_leafminer_a_serious_pest_of_a_favorite_landscape_plant
Note that the timing for management using contact insecticides would be right around the time that the adult flies are laying eggs in the spring. This timing coincides with blooming of Weigela bushes and is also about the same time that the boxwoods will be producing their own flowers. Boxwood produces small inconspicuous flowers along the tips of last years shoots (see attached photo). This is the ideal timing for an insecticide application targeting the adult leaf miners. However, applying contact insecticides to a blooming boxwood is a sure-fire way to kill bees and other pollinators.
And finally, the link below includes some excellent pictures to help you ID and control boxwood leafminer. Good luck!
The link below from Clemson University will give you excellent information about boxwood leafminer and its control. Scroll down to "Insects and Related Pests," and you will find the info on Boxwood Leafminers.
https://hgic.clemson.edu/factsheet/boxwood-diseases-insect-pests/
It's a good idea to confirm that it is really leafminer that is affecting your plant. You can open a few leaves and see if any larvae are still present. Here is additional information on how to treat leafminers.
https://www.canr.msu.edu/news/boxwood_leafminer_a_serious_pest_of_a_favorite_landscape_plant
Note that the timing for management using contact insecticides would be right around the time that the adult flies are laying eggs in the spring. This timing coincides with blooming of Weigela bushes and is also about the same time that the boxwoods will be producing their own flowers. Boxwood produces small inconspicuous flowers along the tips of last years shoots (see attached photo). This is the ideal timing for an insecticide application targeting the adult leaf miners. However, applying contact insecticides to a blooming boxwood is a sure-fire way to kill bees and other pollinators.
And finally, the link below includes some excellent pictures to help you ID and control boxwood leafminer. Good luck!
