Food for Thought Regarding Fuchsia Gall Mites
Rodney Bergquist
President American Fuchsia Society
May 2004

If you are going to grow fuchsias, sooner or later you are going to bring home a plant that has fuchsia gall mites on it, so you may as well know how to identify fuchsia gall mite damage and learn what your options are.
The University of California Berkeley did the initial research and ran tests in the early 1980’s when fuchsia gall mites were first discovered in the U.S.
I have read the University of California Berkeley test results written in January 1983-85 AFS Bulletin articles. I want to acknowledge the research, studies and articles written by previous AFS members. I have read all of the available AFS Bulletin articles written about fuchsia gall mites during the past 20 years.
I also had the opportunity to discuss with Dr. Peter Baye the importance of how to treat a gall mite infected fuchsia. For those of you who do not know of Dr. Peter Baye, he is a long time member of the American Fuchsia Society (AFS), has a Ph.D. in Botany, and is a hybridist who raises fuchsia gall mites to test on his newly hybridized “mite resistant” fuchsias. After studying all the available information, including the notes I made during and after my discussion with Dr. Baye on how to successfully treat a gall mite infected plant, I came to the conclusion that I needed to share what I learned with you.

INFORMATION about Fuchsia Gall Mites

What are fuchsia gall mites? People who have seen them say you need a 40 + power microscope to see them, so most of us will never see a fuchsia gall mite. Gall mites are not insects; they are members of the spider family. They have a worm-like whitish to yellow body with two pair of legs. Gall mites congregate around new leaf and flower buds. The gall mites feed on new growth and sooner or later the females lay eggs. The eggs hatch in one to two weeks. As the new leaves or buds starts to grow each gall mite punctures the new growth and starts injecting a growth hormone substance that causes the plant tissue to swell and become disfigured. In two to four weeks the babies become adults and move to new locations on the plant.

How to Identify Fuchsia Gall Mite DAMAGE

What to look for:
Plant parts are “fused” together.
Plant parts are “SWOLLEN” and twisted,
Infected area looks “HAIRY”.
Infected area sometimes looks “reddish”.

Question: How did we get to the point that we now have a Fuchsia Gal Mite Problem?
Answer: In the early 1980’s popular fuchsias became infected with fuchsia gall mites. Because they were and still are very popular plants, everybody wants one and because we cannot see fuchsia gall mites on the plant, lots of cuttings have been made and distributed to fuchsia growers and nurseries during the past twenty years.

Question: Why are gall mites so difficult to get rid of?
A) When you see gall mite damage on a plant it is a QUANTITY issue. When you see one gall mite infected area on a plant, that one infected area has over 100 adult and baby gall mites feeding on that plant. Which means in one season, the gall mite count can quickly become hundreds if the plant is not treated. Gall mites are like head lice. They are all over a plant and not just at the infected area that was just cut out.
B) Most products you spray with are consistently able to kill a reasonable number of gall mites per application, however it is not realistic to believe that one application will kill every live gall mite and smother every egg on the plant. That's why almost all spray products recommend that the plant be sprayed two or three times.
C) This PARTIAL TREATMENT only provides temporary relief. UC Berkeley test results recommended the following: as soon as you notice the gall mite damage on your plant, cut out the infected area by cutting back at least two nodes below the gall mite damage, and then thoroughly spray the plant. This effort will reduce fuchsia gall mite numbers to such low levels that several months of gall free growth can be enjoyed. Its interesting to note that most fuchsia growers have echoed these UC Berkeley instructions for the past 20 years.

Question: What is your understanding of what will reduce gall mite numbers?
Question: What is your understanding of the enjoyment of several months of gall free growth?
Answer: To me, it means my fuchsia still has live gall mites on it that will re-infect my plant again at a later date. It also means I can spread the surviving gall mites to other cultivars that have never been infected before.
People say that fuchsias always get fuchsia gall mites, when in reality, for the past 20 plus years we have only been reducing the number of gall mites on infected plants. I believe that most popular fuchsias that had fuchsia gall mites on them 20 years ago still have gall mites on them today.

Question: HOW ARE FUCHSIA GALL MITES SPREAD to other fuchsias?
Because of the following example, I suspect that our hands and fingers spread most of the fuchsia gall mites from one plant to another. Remember that we cannot see mites on the plant when we buy it. Its worth noting that I have had some of my new plants for four or five months before the plant broke out with gall mite damage. During that time, I did what a lot of people do I went from plant to plant using my fingers to kill the whiteflies on the leaves because I didn't want to spray. I repotted several plants one after the other, pinched new growth going from plant to plant, made numerous cuttings touching several plants in a row, removing and picked up old leaves and flowers going from plant to plant. And of course we cannot forget about the possibility that hummingbirds, bees and wind may also spread the gall mites.

FOR FUCHSIAS GROWN IN CONTAINERS OR POTS

Gall mite infected plants are high maintenance plants that require a significant effort on your part. After reading all available AFS articles written about fuchsia gall mites the past 20 years, not one article mentioned anything about cleaning all the gall mites off our plants. Now I think I know why. Let's say you have a fuchsia in a pot that has gall mite damage. If you decide to treat it, your going to segregate the plant, cut out the infected area, sanitize your tools with some sort of disinfectant and wash your hands. Then you have to go put on your spraying clothes and gloves, mix a spray solution, spray the plant, clean the spray container and wash your hands and clothes. Then in a week do it again.
How much frustration are you willing to endure for an $8.00 plant? It finally dawned on me, I think the reason nobody talks about cleaning all the gall mites off our fuchsias is because you are not supposed to go through all that effort and frustration for an $8.00 potted plant.
You can throw potted plants that have gall mite damage in the trash. Why should I throw it away? Plant care maintenance is normally done, using our hands and fingers going from plant to plant. Dr. Peter Baye told me that a plant that has fuchsia gall mites on it serves as an excellent source for infecting an entire collection. It is almost impossible to care for a gall mite infected plant without infecting other fuchsias. I believe we should consider fuchsias in pots as annuals. Buy a bunch of new ones every year and if a fuchsia shows gall mite damage, in the trash it goes. Next year, buy some more fuchsias, with different names, that have the same color combination you like or better yet, try some of the new introductions. If you throw an infected plant away, throw it in the regular trash bin and NOT in the yard waste recycle bin.

FOR FUCHSIAS PLANTED IN THE GROUND

Consider the following: How can I clean all the gall mites off the fuchsias I have planted in the ground? I asked Dr. Baye that question. He said PRUNE the plant back as far as you dare and REMOVE ALL LEAVES, flowers, buds and all loose bark from the plant. Gall mites are on the leaves and can be on flowers, buds, stems, and branches and could possibly be on the surface of the potting soil. Gall mite eggs are sometimes laid under loose bark, which will protect the eggs when you spray. Use a toothbrush, glove or some other method to remove all old loose bark. Clean up any fallen leaves that may have live gall mites or eggs on them.
I believe this to be the CRITICAL STEP. AFTER you have PRUNED and REMOVED ALL THE LEAVES and before the plant grows new leaves, spray your plant two to three times, seven to ten days apart, with a product you believe to be effective in killing fuchsia gall mites. With no leaves on the plant you should be able to do a thorough job of spraying every inch of the stripped plant. However, once the plant starts to grow new leaves your chance of being successful decrease significantly.
SPRAY PRODUCTS: It is important that everyone understand that pesticides or horticultural oil products are contact sprays. In order for them to be effective, the oil must come in contact with every live gall mite and smother every gall mite egg. The only way oil products can be effective in killing gall mites is for you to remove the leaves as Peter Baye recommends.
Some toxic sprays only kill the adult gall mites but do nothing to stop the eggs from hatching. That's why you need to spray more than once to make sure you kill the young gall mites that hatch before they become adults and lay more eggs.
Systemic: Its worth noting that the people I talked to who consistently use some sort of systemic, say they do not have fuchsia gall mite damage on their plants. Our local nursery advises that systemic products are very strong chemicals and must be used with caution. Always water plants thoroughly before applying a systemic.
Check with your local nursery for the current products available in your area. Make sure fuchsia gall mites are listed on the product label. Please, follow all manufacturers recommended dosage, safety precautions and spray intervals.

REDUCING THE NUMBER OF GALL MITE INFECTED PLANTS

In summary, at some point we need to stop spreading fuchsia gall mites to the plants that are not currently infected. When you cut out the infected area and spray the plant, without removing the leaves, you are only reducing the number of gall mites. That means the gall mites left on the plant can spread to other fuchsias. We need to stop reducing the number of gall mites on our potted plants and start reducing the number of potted plants with fuchsia gall mites. I believe we should all consider throwing fuchsias grown in pots or containers with gall mite damage in the trash for the next several years. Maybe we could pull most of the infected fuchsias out of circulation.
My concern is for the fuchsias of the future. If we continue to only reduce the number of gall mites on our fuchsias, isn't it realistic to believe that sooner or later gall mites will ultimately be spread to all fuchsias? Will having gall mites on your fuchsias become the norm? What you decide to do with gall mite infected plants will have an impact on fuchsia culture for many years.