Worms in Cherries
Question from Barbara:
My daughter called me last night, upset because she discovered that many of the cherries she and her son had been eating (from their own tree) contained little white worms.
They live in Pleasant Hill, CA (Contra Costa County) and have never had this problem before. The tree is several years old, located in her front yard which faces south.
We’ve searched IPM info, but can’t find any suggestions that would eliminate the problem for next year – except really serious pesticide spraying.
Is it possible to grow organic cherries? Do you have any suggestions?
Answer from Pat:
Tiny white worms are an increasing problem with home-grown cherries of both sweet and tart varieties. These worms are the larvae of the Western cherry fruit fly (Rhagoletis indifferens Curran), first discovered in Colorado in the late 1990’s. The first thing to do is to report this infestation to your local agricultural department or UC Farm Advisor. It’s important that these agenciest monitor this pest since it threatens commercial groves.
The larvae of Western cherry fruit fly don’t harm human beings who have accidentally ingested them since they are not adapted to living in human intestines, and they are mainly, after all, made up of cherry meat, but it is certainly a disgusting thought to know you have been eating worms. Western cherry fruit flies emerge in spring from pupa that have wintered over in the ground under the trees. As soon as they emerge they fly up into the tree. These black flies are tiny with striped wings are sluggish flyers. People seldom notice them, but yellow sticky traps can catch them and tell you of their presence. Most stay in the same tree but some are blown by wind to other trees. Their lifespan is about 15 to 35 days. They can lay eggs seven to ten days after first emerging when the temperatures are about 75 degrees Fahrenheit to 85 degrees in daytime. They eat aphids and honeydew. Once they mature, they mate and females pierce holes into fruit, laying one egg inside each cherry. The eggs hatch inside the cherry and tiny larvae commence munching. After the larvae mature and get fat inside the cherries they drop to the ground and bury themselves in the soil under the tree where they pupate and remain in dormant state until emerging as flies in spring. Then, once again the process repeats itself. Unless checked they will become worse every year and will spread to all other cherry trees in your area.
Unfortunately, the solutions given by experts are often to spray fruit repeatedly to kill the flies before they can lay eggs. Also with a pest that occurs in various stages experts may recommend attacking it with various specific products to kill the pest at different times of year. Otherwise you couldn’t possibly get them all.
The safe way to get rid of this pest would be to interrupt its life cycle in an organic or natural way without using pesticides, but I don’t have a cherry tree and cannot try out these controls. What I recommend is cleaning up fallen twigs and leaves under the tree, then spreading a layer of dry bagged earthworm castings now under the tree to kill the worms as they fall to the ground. Cover the ground from the trunk to the drip line and a foot or two beyond. Earthworm castings contain chitinase which destroys chitin, the exoskeleton of insects. Insects are killed when trying to burrow through a layer of earthworm castings. Renew the castings in late winter to kill any remaining flies as they emerge and keep it up from year to year. A few fruit flies will migrate into your garden but the castings will get them so they won’t be able to proliferate. This system works for giant whitefly on begonias which have a similar life cycle in the ground under the plants and then emerging to attack the foliage. If you try it please report back with your results.
The Colorado State Cooperative Agricultural Extension recommends putting yellow traps into trees to make sure when flies are first present, and then repeatedly spraying the trees with Spinosad every seven days to get the various generations of flies while they are present. Spinosad is an organic spray but harms bees if used where bees are found. Also, I fear that using it in great quantities will eventually destroy its efficacy.
You are amazing! If we had a designation akin to Japan’s National Treasures, I believe you would definitely be in that class for gardeners. Thanks so much. I’ve shared your message with my daughter and will surely let you know how things go.
What a lovely reply. Many, many thanks!
My daughter took your advice and took samples of her infested fruit to the Contra Costa Ag Department. The entomologist provided both her and our 4 year old grandson with a great illustration of science at work. The pest has been identified as Drosophilla Suzukii. The link to the UC Davis IPM page for information about this pest is: http://www.ipm.ucdavis.edu/EXOTIC/drosophila.html
Its potential is absolutely horrifying, and it’s likely they’ll make it down here sooner or later. Thanks once again for your willingness to help. I’m very glad you’re here for all of us.
Thank you so much for replying with this important update with the UC Davis IPM page about Spotted Wing Drosophila (Drosophila suzukii). Many thanks to your daughter for immediately acting on my suggestion and taking samples of the pest to the Contra Costa Ag Department. I thought from your descriptions that the pest was the Western cherry fruit fly but now we know it is not. This new exotic pest sounds even worse, but it is good news that there is some evidence that traps made from empty yogurt containers may provide one way of controlling it. I urge all readers who have cherry trees to read the information on the link you have so kindly provided.
I heard that letting the cherries soak in water bring the worm out.
I have these flies in my cherries too and I live in Newport, WA. (About an hour and a half from the Canadian Border and also on the border of Idaho.
If I “can or freeze” these cherries with the little white worms in them will they be noticeable when I get the cherries out to bake a pie??? Will canning the cherries whole with the little larvae in them spoil the fruit. Will I notice them in my pies???
It is so much trouble to pick them out that I would rather cook the little buggers unless that would be unhealthy. Thanks Sharon Davison
Most fruit pie recipes begin by saying “First, inspect and pick over fruit and cut off any bruised or damaged portions. Before cooking your cherries, I suggest you phone your local UC Extension office and see if they have an official reply to your question, since it seems to be something many folks would like to know. Below is my personal opinion, based not on scientific inquiry but on common sense:
Many insects and worms are edible and are a good source of protein. We know that worms and maggots of various sorts were eaten by ancient man and are still consumed today in some countries. Various types of worms, locusts, and ants, though disgusting to most westerners, are prepared in special ways to make them delicacies in some countries. However some insects, most notably certain caterpillars, have a bitter flavor and a few tropical kinds are poisonous. Cherry worms are not poisonous and don’t seem to have a bitter flavor, nor do they harm humans who ingest them since many people say they’ve eaten them by mistake without realizing what they had done and they had no ill effects. The main problem is when the worms consume the insides of the cherry and render the fruit itself unpalatable. Also, we have to face the fact that the cherry, once consumed by a worm contains what has gone through the insides of a worm and come out the other end. If you picked the cherries early while they are still in good shape I think it’s okay to cook them, but if later in the season the cherries themselves will be spoiled and won’t taste good in pie. High heat necessary to cook a pie, will sterilized the damaged fruit, but I can’t guarantee that the flavor or texture or look of the pie will come out right. My suggestion: try it and see. A few worms won’t hurt but masses of them might.
I eat them all the time fresh off the tree; sorry we can’t market them as ‘protein plus’ .
for three years now. I eat about lb a day from July 1st
through July 21.
… it’s just a little protein and does no harm — initially
a speck; about the size of a pice of long grain rice when
full grown. Hardly worth sweating over … but we are so squeamish here.
They are very small … once picked, chill cherries
as soon as convenient; it stops their activity, and
they will remain edible for four or five days … or more.
in the fridge.
I do cut in half and remove worms (1 in 4) from any I plan to share with my squeamish friends and family.
I leave whole the ones I freeze for personal consumption.
NOTE: you can fit more in the freezer if they’re cut in half … and there is less air space so they keep longer.
I freeze enough for 10 months. This year I froze extra – hopefully enough for 12 months. 🙂
Thank you for your comment which I truly appreciate. Even though not everyone can adopt the same attitude, your healthy and down-to-earth views might help some folks to chuckle about this subject and not to feel quite so upset with an otherwise frustrating situation. As you say, many people are squeamish, and I am glad you wrote to share your experience and honest opinion and tell others how you deal with this problem including your useful tips on pitting, storage and freezing.
We live in a squeaky clean society and most folks don’t grow up in the country where a peck of dirt and a few critters thrown in is par for the course.
I am very happy and reassured to find this site as I have been slicing and pitting cherries all day, along with disposing of the little worm in order to put the fruit in my dehydrator. I live in Western Colorado and have 5 cherry trees. I haven’t noticed the worms before today and I have been picking, eating, and sorting for a week. This is the first year we have gotten cherries as the aphids have got them in the past. Now to solve the worm problem. I am relieved that I have not been wasting my time as this is a tedious job and the worms have disheartened me. Now I’m wondering how I can get the cherry stains off of fingers, nails and cuticles. Yuck!!!!
Look for little holes in the cherries first. If you miss some the lukewarm water rinse b4 canning and hot syrup will make them surface. If there are not too many I skim them off. I never had them b4 for many years then all of sudden they started up -one year I had to disgard the whole crop AFTER picking them. We are going to try the cherry bait next. Even though we can get rid of them b4 canning it is gross. I have never noticed any spoilage. Didnt realize I had them 1 year and dried some cherries & found them fried at the bottom of the dryer. Have read the worms won’t hurt you if accidently ingested.
Thank you for writing to us on this subject and explaining more ideas to folks, such as the the lukewarm water rinse and hot syrup to make the worms surface so you can skim them off. That will work if there are not too many. Yes, when cooked, the worms are not harmful to ingest but they are unpalatable and make the fruit mushy. At their worst they ruin the fruit.
My neighbor also has the worms in cherries; cans them as is; the worms sink to the bottom of the canning jars; she serves/uses the cherries off the top with worm in them any more.
This is excellent news. I am sure many people will be happy to know this so thanks for sharing.
I’d like to tell you about another way to prevent cherry worms. It’s a
fine mesh net that covers the whole tree and can be used year after year.
I’ve been using one for 6 years and haven’t had a single worm in any
cherry since then. The net is still very strong and stretchy, even though
I put it on an apple for a while in the fall to keep the turkeys out.
I’ve also designed a different type that comes in long (75 metre) lengths
to cover grapes and prevent wasp and bird damage. The people who have
used it say it’s saved their crops.
You can find more information at http://www.kootenaycovers.com or email me at
mroberts@kootenaycovers.com.
Thanks,
Marilyn
Thank you for creating a way for gardeners to grow unsprayed cherries free from worms and other pests. Recently while eating “organic” cherries with my family, I said, “I wonder how one grows such good cherries the organic way? Do you think farmers cover the trees with netting—like bird netting?” Now I find someone has invented just such a device.
Thank you also for writing to tell me about it. Now I can spread the word. This fall when I give my slide-illustrated lectures, I will tell folks about Kootenay Covers. The video on your website explained it well. If I had a cherry tree I would send for one of your “box-like” bags immediately.
Many many thanks for what you are contributing to agriculture worldwide. Your bag for grapes would save much heartache for many vineyard owners, including friends of mine. I will tell them also about the Kootenay Covers.
We have noticed these worms in our cherries for the past 2 years. We,too, live in Pleasant Hill and have 2 cherry trees. One is affected, the other is not. I didn’t realize that I needed to contact my local agricultural department but will do so ASAP. Thanks for the information about the earthworm castings. We will try that.
Good luck and hope it works! Another idea is to completely cover the cherry tree with netting. http://www.jgpress.com/inbusiness/archives/_free/001366.htmlThere is a woman who invented the nets. See this funny video. I hope it does not keep folks from buying the nets! Here is another way to net the tree: http://gardeningafterfive.wordpress.com/2011/06/16/gizmo-makes-netting-fruit-trees-easy/
A coworker in upstate NY told me that in his childhood home they had a dozen cherry trees, never sprayed, and never had worms. They planted a vine next to each tree that flowered in the spring and the blossoms produced a natural pesticide.
But he didn’t know the name of the vine.
Do you?
The worms in cherries were first discovered in Colorado in the 1990’s. Unless your friend’s childood was within the last ten years or so it is unlikely that the cherry trees where he lived as a child ever had any worms in them anyway, and it did not require a vine to kill the moths that cause them, since there were none. On the farm where I lived in the 1940’s we had a sour cherry tree growing in a hedgerow. The cherries from this tree made the best cherry pies I’ve ever eaten. They had no worms or anything else and many plants, including honeysuckle, grew in the hedgerow with that tree. Perhaps honeysuckle was the vine, but I do not know this for a fact. Despite the fact that there might have been no worms in cherries when your friend was a child I would love to know what vine it was that they planted, but I have never heard of this before and cannot imagine what it was. It would be nice if someone were to read this who knew the answer. Possibly there was or is a vine that acts as a trap for moths, luring them away from the cherry blossoms. Many times bugs are confused when several different plants are grown together instead of just one.
We had worms in cherries in the 80s in a tree at a house we purchased in 1980, so I’m not sure why they say they only showed up in the 90s. I was eating them when a friend sliced one open for me and showed me a little white wiggly worm inside each one. I didn’t eat them any more. It was an extremely old tree. Might not have been the exact same moth, but it was definitely a little white worm inside a cherry from our tree.
Surprised that people say cherry fruit flies and larvae only since the 1990s! I can’t speak of them before the 1970s, but definitely had them in our Bing cherry tree at that time. Southern British Columbia, right near the 49th parallel.
Yes, they were in Canada. As with many pests, the problem has spread.
Hi there, I stumbled upon this site because I too found I had consumed these little worms after taking a small bite and seeing the things wiggle within. I got my cherries from my boss’ tree. She has a cherry tree next to an apple tree in her back yard up in El Cerrito, Ca. She’s very green and greatly dislikes chemicals. I want to tell her but don’t know the best way to do it and how which wont have her worry for the kids, because she runs a preschool there in her house.
Eating the worms won’t hurt you. Neither will they harm the kids in the pre-school, so don’t worry and be glad you are not raising the cherries yourself. In that case you would need to tent the tree or find other means of controlling this pest. You can kindly ask your boss someday “Oh, by the way, did you know that there are worms in your cherries? Ha, ha! I ate a few of them by mistake. I know they won’t hurt me but just wondered if you know.”
Hello girls – it´s amazing – I live in Europa – and we have had worms in cherries every time (excuse my english – it´s not my mother language) – when I was a child, when my mother was a child, my grandmother and also my grandgrandmother (I don´t know more). So people in Europa normaly eat cherries with worms. I don´t like it, so I open and check everyone. Before coocking we everytime put them in water with vinegar and the worms get out – anotherway You will have them in Your canned cherries. It´s amazing for me to hear, that in U.S. they weren´t before 90´ies. Here in Europa we didn´t have worms in carrot and onion before – and now they are there sometimes. And I heard that in America are some small worms in strawberries also. It would be amazing when we have no insects in fruits. I wish You tasty cherries without worms! Lenka
Lenka – i also live in Europa, but I’m from Canada. Can you tell me more of the vinegar and water idea. I have cherries from a friend, and have worms. I don’t know what to do to get the worms out. I heard someone say you can boil the cherries – but I don’t if that is a good idea. Thank you for any help you can give me!
Hello Anetka, I wasn´t here for a long time. Yes – you can put them in a water with vinegar – cca in 10 l water put 1 dcl of vinegar – and the worms get out – but the products of their digestion stays still in cherries. 🙁 Our grandmams did it this way. I better don´t eat cerries with worms.
I grew up in southwest Idaho. We always had these little buggers (late 1970’s), and they had been around for a while. Maybe the data about them showing up in Colorado in the 90’s should not be extrapolated to the rest of the US (unless it’s a different type?). I’ve pitted and canned cherries and when you open the jars you’ll see them floating up on the top- I’ve done the raw canning method. This time I’m going to try the hot pack canning method of boiling first and skim them off the top before putting into bottles. I’ll do vinegar too :). Extra protein yes, appetizing, no. Thanks for all the good info!
Thanks so much for your helpful information.
I’ve spent the last two seasons trying to get rid of the curculio’s, only to find small, white worms in some of the cherries. I throw the obviously infested ones away. Is there something particular I should be spraying the tree with?
This pest now attacks other soft fruits including blackberries, raspberries and blueberries. Tenting is the best solution. See the link below. I do not believe in continual spraying with pesticides. Your health, the health of your family and of the planet is more important than a few cherries. Please read what I have already written on this subject and read the comments of others. Most importantly, please read what the University of California says on this subject here is the link:http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74158.htm I think tenting the tree is the best solution if a tree is not too large, and such tents are already being sold.
I have a neighbour who is now 86 now. I told her about the worms in our cherries. She told me they are night time cherries and to go out and eat them when it is to dark to see the worm hole. That is what I did, now I even go out and eat them during the day and think to myself die you little buggers.
Wayne
Nakusp, B.C.
Canada
Thank you so much for this amusing comment. The worms are probably a good source of protein.
So.. if one cans cherries with worms, do you have to adjust canning time or recipe in order to can safely ?
The usual canning time should be fine but looking at the dead worms as you eat might be off-putting.
Thanks Pat & everyone for providing such interesting comments and solutions to the cherry worm problem that I didn’t even know existed. As a vegetarian, I’m now a little concerned about raw cherries I’ve eaten in WA and the cherry preserves my friend gave to me! My question: do the worms invade native Catalina cherry trees (Prunus illicifolia spp lyonii)? I noticed cherries for the first time this year and I’ve been hoping the neighborhood birds would enjoy them.
ps this tree has grown very well in West LA’s heavy clay, now 8ft from the 5-gal tree I bought at Theodore Payne in the Fall of 2012. I tried several species to create a screen, but the Catalina Cherry has done the best (Lemonadeberry is doing well too, but more open & slower growing, and I sadly lost the others) — I think I’ll plant more this coming year!
I have no idea whether worms are a problem with Catalina cherry trees, but if so they are no problem for the plant or for you since we don’t plant this tree as a food crop.
Pat
Years ago I went to then Yugoslavia and people on the trip were eating cherries out of the trees. The locals said to be sure and soak them for the worms to come out. Don’t know if that works but their you have it !!
Thanks for comment. Did they say to put salt or vinegar or anything else in the water?
In Haiti we have a few fruits trees how bear fruits. But the fruits are rip the full of white small worms. would appreciate to know how to treat the trees not to have those worms your help in this matter will be appreciated thanks in advance
I am surmise that you must live at higher elevations and be speaking of deciduous fruit trees, perhaps cherry? In winter when the tree drops leaves be sure to prune the tree. Then clean up all debris under the tree. After cleaning the ground go over the bark scraping away any mess or lingering debris and bagging and disposing of it outside the garden. Then using protective clothing for yourself and wearing rubber or vinyl gloves, spray the tree with dormant spray 3 times or once a month during winter. If it rains right after you spray, then repeat the spray.
In future, if you can, cover the tree with mosquito-netting designed to protect garden plants from bugs. (This works best for small trees.) Purchase the netting online and cover the tree with it after the tree drops its flowers and sets fruit. If you do this carefully it can prevent night-flying moths from laying their eggs in the fruit.
At my Columbus Ohio home I planted two Bing cherry trees, three apple,two pear, and a peach trees six years ago along my driveway. The last couple of years they all are bearing fruit. I have noticed that all of the fruit has signs of some type of bug I festation. Last summer my cherries had the little white worms. I read the previous post about sprays and nets. Is there an organic spay that can be used. Also I would like to know if these worms and flies are the problem with my apples and peaches?
Yes, there is an organic spray called Kaolin clay. Also ask your Farm Advisor or Agricultural Extension, since efforts are on-going to control the fruit fly that lays the eggs that become the worms. As for your other question: Will this pest infect your apples, pears and peaches, luckily no. This horrendous pest only attacks cherries. One way to avoid the problem is to grow a variety that bears fruit ripening early, before the fruit flies hatch out and lay their eggs, but for those who want to grow bing cherries that is not an option. Personally I believe the netting is the best solution if one can devise an easy way for covering your trees. My advice is this: Put your inventive cap on, figure this out and you have the problem solved. This is how I like best to live. I enjoy figuring things out and trying to outwit the low balls life sometimes throws at us! Also, I am not afraid to hire help to give me a hand in putting my plans into action.
I am going to put some worm castings under my cherry tree and hope it will keep the worms out. But I can’t find any info on how thick it needs to be put down or if you can still water under the tree or will it ruin the castings? Thanks for any help you can give me.
Unfortunately 2 or 3 inches thick for worm castings, which is quite thick, really works but with cherry worms I am not sure this will help since the pests fly in. Not all live in the ground. Nonetheless any amount of worm castings under the tree would in a sense give the tree more immunity since it would increase the amount of chitinase inside the tree. Chitinase is an enzyme that destroys the exoskeletons of insects. Also any amount of worm castings helps. I keep my Meyer lemon tree virtually pest-free simply by spreading a bag of worm castings under it and over the roots at least once a year.
Re: water: No it does not destroy any of the beneficial effects of worm castings. Irrigation can was away the castings if the ground slopes but it no way effects the beneficial aspects of the castings.
Thanks Pat for the helpful info. Have a great spring & summer. Happy gardening!
I’m so glad this story continues. I was wondering if putting diatomaceous earth around the bottom of the tree to the drip line might help? I have just put some around my strawberries to stop the earwigs and slaters eating them. Also early on in 2010 someone mentioned dried earthworm castings. I might try fresh ones from my worm farm this year. Definitely not on favour of eating them even if my ancestors are from Croatia.
The problem with diatomaceous earth is that a pest must touch it or walk over it to be killed and if diatomaceous earth get’s wet it’s immediately rendered ineffectual. How could one dust an entire cherry tree daily? And how could one protect the tree from dew?
Unfortunately the only viable control is bagging the entire tree in fine netting to prevent the entrance of the egg-laying moths. Look Online for Kootenay Covers!
Would covering the ground around a cherry tree with a large clear plastic sheet that was held in place,with no gaps,trap and kill the emerging flies that came from under my trees?
No this would not work. What would work would be covering the ground with earthworm castings. This would kill the flies as they emerge but it would be very costly
to purchase enough earthworm castings to do the job. Tenting the tree with fine mesh is the best option.
I believe someone upthread mentioned soaking the cherries. I live in SW CO and I usually soak overnight in the fridge; often that gets lots of worms at least poking out or floating the next morning. I guess I don’t really worry about the rest…
Good to know my preserves and pies get a little nutritional boost!
Thank you for your helpful comment. Yes, I agree with you that a few worms won’t hurt. It’s mainly aesthetic.
I am from northern va near Washington, DC and saw something on FaceBook about worms in cherries that made me research. This comes after eating about a pound of Black Cherries. I am so grossed out, I am not sure what to do. I have cut open SEVERAL cherries before eating them to find nothing. my fingernails are dyed purple from pinching. Is this a Washington State/Midwest/West Coast thing? I LOVE cherries!! Plus they are on sale $1.99/lb!!! Crazy!!! I get them from our grocery store.
I eat cherries often. Store-bought cherries do not contain worms.