Aphids, aphids, aphids! - Ask Extension
I have had aphids on my Brooks prune tree for about 5 seasons, reducing yield and attacking young growth. I have tried neem oil, horticultural soap, ...
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Aphids, aphids, aphids! #878131
Asked July 21, 2024, 2:54 PM EDT
I have had aphids on my Brooks prune tree for about 5 seasons, reducing yield and attacking young growth. I have tried neem oil, horticultural soap, ladybugs - nothing works to get rid of them. They were on nearby hops plants this spring and I got rid of them with a hose. Not so lucky with two Japanese honeysuckle, killed one last year and one this year. Any advice on anything short of a flamethrower is greatly appreciated!
Linn County Oregon
Expert Response
Dear Zeeknos,
Aphids have been overly prevalent for months in our area, more so than last year, literally covering rose buds and other plants almost completely.
Aside from a shot of water to remove them from the plant (they usually cannot get back up to the area where they were feeding) you can use biocontrols pretty effectively.
However, if you purchases lady bugs in a local store, they will not stay in the area and they, while good at eating aphids, will not do the job the lady bug larva will do.
Do a Google check of insectaries in the Portland area. You will find information on important predators for aphids. They include brown and green lacewings, rove beetles, lady bugs in larva form and various fly larva. The syrphid fly larva are also predators. They are also known as hover or flower flies. They have been known to reduce aphid populations almost 100%. The lacewings are also called the aphid lions because they eat so many.
Another insect is the aphid midge which may also be available through insectaries or parasitic wasps. The parasitic wasp pierces the aphid body, lays an egg which hatch and feed on the inside of the aphid.
You should also control ants. Ants herd aphids and collect their honeydew, a sticky substance that can accumulate on the leaves. It also collects dust and contributes to sooty mold on the leaves. This can easily be washed off with water though.
Keep ants from the trees by using a piece of cardboard around the base of the tree, tape the bottom to the tree all the way around. Then smear the cardboard with petroleum jelly or any sticky substance, tangle foot, that you can smear around the entire piece of cardboard. This prevents the ants from climbing the tree. You may have to clean it off and re-apply if dust clogs the jelly.
Ants will attack predators that are trying to eat or lay eggs in the aphids.
Aphids lay their eggs on leaves and can reproduce 60-80 live nymphs which look like adults but are smaller. Each aphid is born pregnant.
In the fall, aphids with wings are produced as well as male aphids to mate and produce eggs.
A good fall spray is horticultural oil which will smother any eggs of any insects on the tree. Cleaning the area which they have heavily contaminated will keep eggs on fallen leaves from hatching near food sources.
For your garden area the following plants are known to keep aphids away: garlic, chives, leeks, catnip, fennel, dill and cilantro. Most herbs are not bothered by aphids: lavender, thyme, rosemary, and sage. Planting these plants between your aphid loving plants will also help.
You can also make insecticidal soap, using 1 tablespoon of castile soap (peppermint or lavender scented is good) and 1 tablespoon of any veggie oil in a squirt bottle then fill with water. Shake it every time you spray to keep the liquid emulsified. Spray both the top and bottoms of the leaves.
This will kill any insect so be careful that you do not hit pollinators. Many pollinators are flies by the way. So it is best to spray when pollinators are not around.
I am adding a link on aphid growth: https://www.google.com/search?q=life+cycle+of+an+aphid&rlz=1C1VDKB_enUS1030US1030&oq=life+cycle+of+an+aphi&gs_lcrp=EgZjaHJvbWUqBwgAEAAYgAQyBwgAEAAYgAQyBggBEEUYOTIICAIQABgWGB4yCAgDEAAYFhgeMggIBBAAGBYYHjIICAUQABgWGB4yCAgGEAAYFhgeMggIBxAAGBYYHjIICAgQABgWGB4yCAgJEAAYFhgeqAIAsAIA&sourceid=chrome&ie=UTF-8#fpstate=ive&vld=cid:7ffb1472,vid:HVTitHBwpN0,st:0
It is very important that you are able to identify predator larva insects such as the lady bug or lady beetle. Here is a link with pictures: https://ipm.ucanr.edu/natural-enemies/sevenspotted-lady-beetle/#gsc.tab=0
If you have further questions, please contact us again.
Aphids have been overly prevalent for months in our area, more so than last year, literally covering rose buds and other plants almost completely.
Aside from a shot of water to remove them from the plant (they usually cannot get back up to the area where they were feeding) you can use biocontrols pretty effectively.
However, if you purchases lady bugs in a local store, they will not stay in the area and they, while good at eating aphids, will not do the job the lady bug larva will do.
Do a Google check of insectaries in the Portland area. You will find information on important predators for aphids. They include brown and green lacewings, rove beetles, lady bugs in larva form and various fly larva. The syrphid fly larva are also predators. They are also known as hover or flower flies. They have been known to reduce aphid populations almost 100%. The lacewings are also called the aphid lions because they eat so many.
Another insect is the aphid midge which may also be available through insectaries or parasitic wasps. The parasitic wasp pierces the aphid body, lays an egg which hatch and feed on the inside of the aphid.
You should also control ants. Ants herd aphids and collect their honeydew, a sticky substance that can accumulate on the leaves. It also collects dust and contributes to sooty mold on the leaves. This can easily be washed off with water though.
Keep ants from the trees by using a piece of cardboard around the base of the tree, tape the bottom to the tree all the way around. Then smear the cardboard with petroleum jelly or any sticky substance, tangle foot, that you can smear around the entire piece of cardboard. This prevents the ants from climbing the tree. You may have to clean it off and re-apply if dust clogs the jelly.
Ants will attack predators that are trying to eat or lay eggs in the aphids.
Aphids lay their eggs on leaves and can reproduce 60-80 live nymphs which look like adults but are smaller. Each aphid is born pregnant.
In the fall, aphids with wings are produced as well as male aphids to mate and produce eggs.
A good fall spray is horticultural oil which will smother any eggs of any insects on the tree. Cleaning the area which they have heavily contaminated will keep eggs on fallen leaves from hatching near food sources.
For your garden area the following plants are known to keep aphids away: garlic, chives, leeks, catnip, fennel, dill and cilantro. Most herbs are not bothered by aphids: lavender, thyme, rosemary, and sage. Planting these plants between your aphid loving plants will also help.
You can also make insecticidal soap, using 1 tablespoon of castile soap (peppermint or lavender scented is good) and 1 tablespoon of any veggie oil in a squirt bottle then fill with water. Shake it every time you spray to keep the liquid emulsified. Spray both the top and bottoms of the leaves.
This will kill any insect so be careful that you do not hit pollinators. Many pollinators are flies by the way. So it is best to spray when pollinators are not around.
I am adding a link on aphid growth: https://www.google.com/search?q=life+cycle+of+an+aphid&rlz=1C1VDKB_enUS1030US1030&oq=life+cycle+of+an+aphi&gs_lcrp=EgZjaHJvbWUqBwgAEAAYgAQyBwgAEAAYgAQyBggBEEUYOTIICAIQABgWGB4yCAgDEAAYFhgeMggIBBAAGBYYHjIICAUQABgWGB4yCAgGEAAYFhgeMggIBxAAGBYYHjIICAgQABgWGB4yCAgJEAAYFhgeqAIAsAIA&sourceid=chrome&ie=UTF-8#fpstate=ive&vld=cid:7ffb1472,vid:HVTitHBwpN0,st:0
It is very important that you are able to identify predator larva insects such as the lady bug or lady beetle. Here is a link with pictures: https://ipm.ucanr.edu/natural-enemies/sevenspotted-lady-beetle/#gsc.tab=0
If you have further questions, please contact us again.
