Fruit tree pest management (mites?) - Ask Extension
We have a large, mature apple tree that I'm pretty sure has had some spider mites (and/or rust mites) on it the last couple of years: some leaves curl...
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Fruit tree pest management (mites?) #858530
Asked February 05, 2024, 11:29 AM EST
We have a large, mature apple tree that I'm pretty sure has had some spider mites (and/or rust mites) on it the last couple of years: some leaves curled and webbed, plus some rust-colored spot on some leaves. But it's not infested, so it still produces lots of good apples (though some do get wormy later in the harvest season). We haven't bothered to treat the tree, as it still produces more than enough good apples and generally looks very healthy (most of the leaves aren't affected by the mites). However, last year, a new (2nd year) cherry tree (that was close to the apple tree) died just after it had started producing its leaves and flowers, and it looked like it was probably killed by spider mites (and/or rust mites). Is there an effective, non-toxic/organic (IPM) way for us to treat our young cherry trees (in winter and/or in spring/summer), to keep the mites off of them? I'm planning to re-plant a new cherry tree soon, but I'm thinking I should not plant it close to the apple tree this year.
Thanks!
Benton County Oregon
Expert Response
Dear Miriam,
Mites seem to be growing in numbers around the area. Treating the trees is an option, however, there are biocontrols that are very specific for pest mites. Predator mites, when set out at the same time as the pest mites start to appear are a good remedy without sprays.
Pest mites: The two-spotted mite is probably on your tree, it is common and can inhabit just about any type of plant. There are red mites, small but you can see them when they move. There are also brown mites. I am just mentioning a few types. The red mites attack most fruit trees, the brown mites attack stone fruits.
A spray for these mites is horticultural oil when buds have swollen but not opened. Cover all buds and bark. This smothers the eggs and any mites that have hatched. It does not affect the pollinators (which do not frequent trees without open blossoms) or the tree. Do not spray when the bees are out and the blossoms are open. It will clog the pollen and can kill the bees.
Predator mites:
Anystis Baccarum - Crazee mite. It will eat thrips, aphids, leafhoppers, spider mites, whiteflies, fungus gnats, and more. It not only eats them, but kills them without eating them and causes disruption for the pests with its crazy movement. They are larger than most mites. Adults are red in color.
Another predator mite is Galendromus Occidentalis. It targets a range of mites: two-spotted, citrus red mite, McDaniel spider mites, apple and pear rust mites. It feeds on nymphs and adults and will eat pollen when mite populations are low.
A. fallacis is noted as working well in nurseries. It is native to our area and overwinters. Local insectaries should have these mites. We do not recommend any specific businesses.
Predators are sold online, mailed to your residence with instructions on how and when to disseminate them.
Aside from predator mites there are other insect predators that eat mites: Green lacewings, brown lacewings, lady bugs, and minute pirate bugs. If you decide to order, nymph predators are usually more voracious than the adults.
It is important to minimize any pesticides. If you decide to order predators, no pesticides should be used. If a spray says it will kill one insect, it will probably kill most if not all insects.
I am providing a link to an OSU publication on biological control of the two-spotted mite:
https://agsci.oregonstate.edu/nurspest/mites/biological-control-two-spotted-mite
If you have an area away from the infected apple tree, it might be a good idea to plant the cherry tree there. However, two-spotted mites move around.
If you have further questions, please contact us again.
Mites seem to be growing in numbers around the area. Treating the trees is an option, however, there are biocontrols that are very specific for pest mites. Predator mites, when set out at the same time as the pest mites start to appear are a good remedy without sprays.
Pest mites: The two-spotted mite is probably on your tree, it is common and can inhabit just about any type of plant. There are red mites, small but you can see them when they move. There are also brown mites. I am just mentioning a few types. The red mites attack most fruit trees, the brown mites attack stone fruits.
A spray for these mites is horticultural oil when buds have swollen but not opened. Cover all buds and bark. This smothers the eggs and any mites that have hatched. It does not affect the pollinators (which do not frequent trees without open blossoms) or the tree. Do not spray when the bees are out and the blossoms are open. It will clog the pollen and can kill the bees.
Predator mites:
Anystis Baccarum - Crazee mite. It will eat thrips, aphids, leafhoppers, spider mites, whiteflies, fungus gnats, and more. It not only eats them, but kills them without eating them and causes disruption for the pests with its crazy movement. They are larger than most mites. Adults are red in color.
Another predator mite is Galendromus Occidentalis. It targets a range of mites: two-spotted, citrus red mite, McDaniel spider mites, apple and pear rust mites. It feeds on nymphs and adults and will eat pollen when mite populations are low.
A. fallacis is noted as working well in nurseries. It is native to our area and overwinters. Local insectaries should have these mites. We do not recommend any specific businesses.
Predators are sold online, mailed to your residence with instructions on how and when to disseminate them.
Aside from predator mites there are other insect predators that eat mites: Green lacewings, brown lacewings, lady bugs, and minute pirate bugs. If you decide to order, nymph predators are usually more voracious than the adults.
It is important to minimize any pesticides. If you decide to order predators, no pesticides should be used. If a spray says it will kill one insect, it will probably kill most if not all insects.
I am providing a link to an OSU publication on biological control of the two-spotted mite:
https://agsci.oregonstate.edu/nurspest/mites/biological-control-two-spotted-mite
If you have an area away from the infected apple tree, it might be a good idea to plant the cherry tree there. However, two-spotted mites move around.
If you have further questions, please contact us again.
