I've had limited success with DE on the leaves. Of course, you have to reapply it whenever it rains.

I have cucumber beetles too, and from what I've read, they are seriously bad bugs. Apparently they LOVE corn, and if your corn is falling over, it may be because the larva are feeding on the roots. (I wondered why my corn wouldn't stand up!) So they recommended some good stuff on this site, and it has a lot of useful information. Here is the link.

Here is a link that might be useful: cucumber beetles

a cup of soapy water. Hand pick them and drop them in the water.

Anney from Georgia has done excellent research and experiments on cucumber beetle traps over the past couple of years. (see link)

Jim

Here is a link that might be useful: Cucumber Beetle Traps

Jim

I'm still working on it!

For those who might be interested, the rationale for this insecticide is to combine two ingredients, a cucumber beetle lure and a cucumber beetle poison. The lure must not attract any other insects to the poison.

The quickest insecticide using these principles to dispatch cuke beetles is to combine clove oil and dental disclosing tablets (made with red dye #28 -- no other red dye works) with water and set it around your plants.

Dissolve one tablet containing the red dye in a half-cup of water. Then mix 3 tablespoons of the dye mixture and one teaspoon of the clove oil and put it in a shallow non-plastic container like a jar lid or even a small metal catfood can so the cucumber beetles can feed on it. Set it in your garden or hang it about 24" high on your trellises. (Clove oil melts plastic so don't use plastic cups.) Save the rest of the dye mixture in the refrigerator and your clove oil separately. Replenish after rain or when it evaporates.

Female cucumber beetles are attracted by the volatiles in the clove oil and will flock to eat it -- but no other insects are attracted to it. The red dye that they ingest along with the clove oil is phototoxic, meaning that it causes a reaction when the insect is in sunlight, killing them in as little as five minutes.

You can replace the red dye #28 with Sevin if you don't have ready access to the red dye and don't mind going chemical. The Sevin does not go in your garden or on your plants, so you aren't contaminating your garden with it. It stays in its container, and it must eventually be discarded, so that's something to think about.

You can also use cucumber "boats" as your container. Just slice a cucumber the long way, scoop out some of the seeds, and soak them in the clove oil and dye mixture for several hours so they absorb them. Then set them around your garden. (They'll disintegrate in place with no harm done to anything.)

Cucumber beetles will decrease in number as the females die. Using this insecticide, I don't see any but one or two stray cuke beetles after a few days.

=====

There are also other lures for both male and female cucumber beetles that can be used. Unfortunately perhaps, they're usually in the form of plants that you must grow as trap crops, so you must plan ahead for cucumber beetle invasions. That's something we don't tend to do until they've really done a number on our plants and we say "never again". (This was the motivation for my efforts to find an organic control for them.)

I am currently growing three buffalo gourd plants in a large garbage can to harvest the roots to use as a lure next year. Cucumber beetles are extremely attracted to this plant and particularly the roots. The plants grow wild in the dry west and midwest and are considered to be very invasive, so I didn't want to set them loose in Georgia soil! When allowed to grow unmolested in their native habitat, the roots get to be huge, weighing in at 40-60 pounds after a couple of years! I don't think they'll get that large in my garbage can growing for just one year, but I don't want to take any chances.

If anyone wants seeds to grow them yourself, just email me. It isn't too late to plant them to use next year. The vendor was delighted at what I wanted to do with the plants and gave me an extra pack of them if anybody else wanted to grow them for this purpose. Later you can save the gourd seeds yourself since it's an OP plant.

I never had much luck getting rid of them, so now I only grow County Fair cucs........which are bitterfree and don't attract the beetles.

I do the same with the County Fair, Catherinet, but I find the beetles are attracted to them, they just don't die as readily as other varieties from wilt.

Unfortunately the beetles usually become numerous enough that they go after lots of plants. Some ornamental plants, beans, any curcubit etc. I don't even both growing corn. I suppose if there was a local market for corn smut I could do that effectively ;)

I honestly don't know of any effective way to control them when they are present in high numbers other than covering plants that don't need insect pollination or using some sort of pesticide.

They are by far the most difficult pest I deal with each year.

Great advice Anney. I'm gonna try that red dye and clove oil mix. Anyone know where I can get some dental disclosing dye??

canuckistani

I had to order the dye online, but some dentists have the tablets that they give to kids to help them see plaque and brush it away! Maybe you can find a friendly dental assistant who can give you some of them.

If you would like to see the background and research that's been done showing the results of using lures and poisons (including red dye #28) to kill cucumber beetles (& corn rootworm, a different stage of the pest), here is The Bitter End, a scientific report on various ways scientists are finding to dispatch them without killing other insects. The article starts with a discussion about using a mutant bitter melon as the lure and then moves on to other plants that are attractants for the insect.

This site lists clove oil as a bait for cucumber beetles, along with several other oils.

Thanks again Anney, great info. Has the red dye + bait really helped you to control the cuke beetle? Will it work well in the first season?

canuckistani

Yes, it really does work. I set out the red dye and clove oil this year after seeing two cuke beetles on my melons. It rained a LOT as I was trying to get rid of them by putting out the bait and poison, and I did find several dead ones submerged at the bottom of the bait-poison liquid that had been diluted by rain. So I've had to replenish it more than usual. Since then I haven't seen a single one, and even if I saw one or two, I wouldn't panic. That few can certainly chew some holes but nothing like the damage from infestations I had two and three years ago.

According to what I've read, the adults actively feed for two weeks and then reproduce. I don't know how long it takes for the next batch to make the next attack, but the more you kill, the fewer young ones there are in the next wave. They also arrive in your garden by migrating or being windblown in, so it isn't a one-shot deal!

I just try to keep a sharp eye peeled for the buggers. I hate them!

Riley 17,

Thanks for sharing that website. I love the sticky trap idea.
It's all natural. and I can use my male squash flowers to create a bait.

The spotted cucumber beetle doesn't overwinter up here, but blows in the winds from down south later in the season. The western corn root worm beetles are another species from striped cuke beetles. All three types are serious pests on corn, melons, cukes, squash, and green beans.

The corn root worm beetle is darkish on top and yellowish underneath. The striped cucumber beetle is mostly yellow on top and blackish underneath.

Aren't the corn root worm the larva of the spotted cucumber beetle? Is the larva of the striped cucumber beetle no considered a pest?

Wayne

Canuckistani is correct. The corn root worm is the larva of the (Southern) spotted cucumber beetle. I am sure I have so many cucumber beetles because my garden beds are right next to a cornfield.

Canuckistani

The larva of the striped cucumber beetle is definitely a pest -- it eats the roots of the plants the adults attack later, a behavior pretty much the same as the behavior of the spotted cucumber beetle larva, which attacks corn roots. This insecticide kills both kinds, should you be as lucky as I am and have them both in the spring and early summer.

I finally got my dental disclosing tablets that I ordered from this website

http://www.dental-mart.com/plaqdistab.html

They look purplish and it says old plaque will stain blue and newer plaque will stain red. Does this sound like the right dye??

canuckistani

They seem to work fine -- that's the kind I got first and reported on above. Recently I went ahead and ordered some tablets that have ONLY the red dye though, just to be sure, and had to order $20 worth before they'd ship them. I can't test the difference yet because I don't have any cuke beetles now to test it on!

I just wish there were something as effective that worked on squash bugs. They give me the creeps and are very hard to control other than by hand.

Anney thank you very much for sharing your research with us!

I spent the weekend looking for the tablets at drugstores and couldn't find them and my dentist doesn't use them. I really need something now to start killing the beetles until I can get the tablets through mail order.

Do you know the ratio of Sevin to clove oil to use? Thanks again.

never-give-up

I'd use the same ratio of Sevin mixed for a straight insecticide as the tablets -- about 1 tsp. of clove oil to 3 TBSPs of the Sevin mix for each container.

Since the clove oil floats on top of the Sevin mixture, you might put a piece of sponge in the mixture to suspend the Sevin along with the clove oil so the beetles will consume both at the same time. Or you can soak pieces of melon or cucumber in the clove oil/Sevin mix and set them in the garden, preferably in a metal lid or something else not plastic if you want to avoid getting Sevin on or in the soil.

Thank you very much anney. I really appreciate it.

Hi Anney,

I emailed the company (wish I had thought of that before I ordered! lol) and they said the only dye they know of it in the product is FD&C Blue #1. Where did you get dental tabs with only the red dye in it?

Thanks again

Thanks loads, Annie. I just Googled dental disclosing tablets, and it looks like Butler makes one with the #28 dye.

Any thoughts about where to get the clove oil?

canuckistani

The link below is where I found the tablets with red dye #28. But remember, you have to order $20.00 worth! If you'd like to buy one of the boxes from me (since I had to order eight of them!), just email me and we'll arrange it.

hepatica

I can't find the Butler tablets saying the red dye is #28. I ordered the clove oil through Amazon but many health food stores carry it.

Here is a link that might be useful: Dental Disclosing Tablets

Sorry Anney, I can't find the link now. Strange, since I used the same words to Google it this time.

Could you also just mix straight dye with the clove oil?

plant squash or cucumbers in succession or plant trap crops...they tend to only go for young cucurbits, and they LOVE canteloupe.

kstatefan
Could you also just mix straight dye with the clove oil?

Only if it's red dye #28, which is not the basis for red food coloring. As for dyes, it's probably impossible to know what red formula is used in Rit dyes (or other dyes) since they don't publish their formulas. There are several red dyes, but red #28 is the only one that is phototoxic to the beetles.

Isn't the toothache medicine that is sold in drug stores pure clove oil? You know the one that comes in a little brown bottle with tiny cotton balls and tweezers. I'm pretty sure it is. It only cost a few bucks.

hepatica I found the clove oil at the Walmart pharmacy.

I found these Butler tablets on Amazon and the ingredients list on another site.

INGREDIENTS
Dextrose, Mannitol Powder, Stearic Acid Powder, Cherry Flavor, D&C Red 28 (Cl 45410), Calcium Stearate, Sodium Saccharin, FD&C Blue 1 (Cl 42090), Sodium Fluorescein.

I tried the clove oil with the Sevin yesterday and so far no takers. I am pretty sure there are females out there as there is what appears to be passionate interaction going on. LOL I took the can and put it on the leaf next to at least 2 dozen individual ones though out the day with no takers. When I knocked them off the leaf into the can they were gonners. Maybe the solution with Sevin should have more clove oil??

Here is a link that might be useful: http://www.amazon.com/s/ref=nb_ss_hpc?url=search-alias%3Dhpc&field-keywords=butler+disclosing+tablets&x=14&y=15

I found the dye here. I thought I might get some and try.

Here is a link that might be useful: Red Dye #28

gardener

I think you may mean Anbesol. It comes in several varieties, and almost all of them contain benzocaine with only a little or no clove oil. You could try it though, to see if the beetles are attracted to it. Maybe they'd be paralyzed to death with the benzocaine! (Just kidding. I have no idea what the effect would be if they ate it.)

never-give-up

Glad you found a source for the Butler tablets that has the right dye.

For it to work, you need to put out several containers of the mixture and leave them there. Give it some time -- they have to find it. Very few of them will die in or near the solution, though I've found several dead ones in it when I used Sevin. None at all in the red dye mixture, but within a few days no more beetles.

The beetles probably also need some kind of perch or place to hang on while they feed if the liquid layer is much depth, which would depend on your container. A piece of sponge would work as a wick for both the poison and the oil.

kstatefan

That's a great link! I'd been able to find only large quantities of the pure red dye costing something like $250.00! The smaller amount is fine, though you'd have to use your own judgment about how much to use.

anney I used a clean tuna fish can and put in a sponge that rose slightly above the liquid. I have knocked about 35 or so into the can and they walk on the sponge for just a few moments and are dead. None have made it out alive at all, so it seems to me that if any went in of their own accord they wouldn't make it out either.

I used an old spoon to remove them just so I'd know for sure if any went in on their own.

I am not sure how to tweek it until I get some tablets.

I kill dozens of them every day on just one squash plant that came up on its own in the compost. All the stuff they would kill that I planted myself I have covered with row cover, but they are blossoming now and I need to uncover them so they can get pollinated.

I'd like to know how much you all are paying for clove oil? I wanted some for watermelon pickles last year and it was $9 for three tenths of an ounce. By the time I see cuc beetles, I'm ready to tear up my garden. They do get on my dahlias and then I spray them.

flowergirl I found it at the Walmart pharmacy. It only came in 1/8 FL OZ bottles for $3.68 a bottle.

No. not anbesol. It comes in a little brown glass bottle with a red cross on it. I can't find mine,but I'm pretty sure it is clove oil.

I planted a nasturtium seed between every cucumber seed and I have not seen any cucumber beetles this season.

He Anney, thanks for this information. I found my first cucumber beetle (spotted) yesterday and my dentist gave me Butler Gum Red-Cote disclosing tablets. Then I bought some clove oil. The jar with the mixture is now at the base of the plant.

Will the beetles die in the jar and that's how I can tell if it's working? Or will I just notice fewer/no beetles on the flowers (I have actually only seen one, but assume they don't travel alone). Also, do you recommend one at each plant or will the jar cover a single area, like 10 SF?

The dye seemed kind of pinkish, I couldn't tell whether it was red dye #28 or not, but I'm hoping to find dead beetles in the jar soon! Thanks!

P.S. My dentist asked me to leave her the instructions so she could try it, too! :-)

Hi, ditnc

It appears that the Butler disclosing tablets do have red dye #28, along with a bunch of other ingredients. I'd think they'd work fine.

It seems logical to me that the redder the solution (the more concentrated the dye), the more of the dye will be consumed at one go-round. When the cucumber beetles' bodies or stomachs turn red, that's when the literature says five minutes in the sunlight kills them. If your solution is only a pale pink, I think I'd add another tablet to the next batch.

I'm not sure where the beetles would die since the poison must be consumed in a sufficient amount and then enough time in the sunlight to work. Remember that clove oil attracts only the females, so you're liable to see some males who aren't able to find any females to reproduce with. But without the females around, the males will leave to find better pickings.

I haven't read all the replies, but the only way I could have cucumbers was to grow the County Fair variety. They're good and I never see one single cuc beetle on them. Otherwise, I would have given up long ago on growing cucs.

Thanks anney, I just looked at my cukes and don't see any beetles. But boy do those bees love the cuke flowers! I need to be careful when I am checking to see what kind of bug's in the petal....

Like a jerk, I treated my powdery mildew on my cuke leaves with Seranade, but no one told me to remove the leaves. I thought the mildew would just go away with the treatment! Duh, so I just today trimmed the bad leaves off. Here's hoping for red female beetles, nice green mildew-less leaves, and of course, a plethora of delicious cukes.

And I ordered some more tablets online so I don't have to keep grubbing from my dentist, although if it works for her, she owes me! :-)

I have tried the red dye solution over the last few weeks with some limited success. Perhaps it is the delivery method I was using, or perhaps the striped beetles we have up north don't like my recipe, because I am still engaged in some serious hand-to-hand combat.

In a shallow tuna can, how deep should the solution be?

I found the cheapest source of clove oil is Ebay.

Anney- where did you find out that clove oil is an attractant to the cuke beetles? Does it attract any other insects?

canuckistani

The link at the bottom of the post mentions clove oil as a lure for *female* cucumber beetles in a discussion about making sticky traps. You can use pieces of cotton wicks stuck to the boards that have been soaked in a Eugenol based oil which is what attracts the female beetles. 2 types of oils that contain 60 to 90 percent eugenol are allspice oil and clove oil. Squash blossoms contain indole which are very attractive to the adults. If you can spare some you might mash them up and stick them to your trap.

There are also a number of other natural lures that might be combined with a poison mixture. Tayuya root powder, buffalo gourd root, Caserta squash, Blue Hubbard squash, Turk's Turban, etc.

And no, the clove oil attracts only diabroticine beetles, which includes cucumber beetles. Eugenol, a naturally occurring insect attractant found in clove oil (82 to 87 percent eugenol), allspice oil (65 to 75 percent eugenol) and bay oil (40 to 45 percent eugenol), lures diabroticine beetles (Peet, 2001 and The Scientific Community on Cosmetic and Non-food Products, 2000). Cinnamaldehyde, found in cassia oil and cinnamon bark oil, functions as an insect attractant and natural cucumber beetle bait (Environmental Protection Agency, 2007). Attach a cotton swab soaked in these aromatic oils to increase the sticky traps trapping effect.

Cucumber Beetles: Organic and Biorational Integrated Pest Management

The ATTRA site above lists common cucurbits ranked according to their effectiveness as lures. Any ranking number over 45 indicates the plant is highly preferred by cucumber beetles, male and female.

You might want to review the list to see if there is anything you could grow next spring to use as a lure as well. The clove oil is usually the best way to start since it is the most readily available lure and doesn't have to be grown -- most people don't plan ahead for cucumber beetle invasions!

m_lorne

Why don't you put a piece of sponge in the solution so the beetles have a place to land and feed from. Just enough solution to keep the sponge wet is all it should take.

My cucumber beetles virtually vanished after I set out my dye traps a couple of weeks ago. What's everyone elses results with this method??

canuckistani

Great!

Next year I'm going to see if I can capture a few and put them in a large clear jar with the clove oil and dye solution in the sunlight and see what happens, since it's hard to know if it works if they fly away to die.

Your big test will be whether any females are around to lay any eggs later since the clove oil is a lure for only the females, not the males. Unmated adults overwinter in neighboring woodlands under leaves and trash. Adults leave their winter sites in late March and lay eggs from late April to early June. Before cucurbits become available to adults, they devour cotyledons and stems. Larvae feed in the soil on stems and roots, become full grown in two to four weeks, and pupate in the soil. First generation adults emerge from late June to early July. A complete life cycle requires from six to nine weeks. There are two and sometimes a partial third generation each year

So if you don't have a second round of them, I'd think that means it worked on the egg-laying females. If you see only a few, they're probably lone males.

I have had zero cuke beetles this year other than a couple spotted early season. This is very unusual in my garden as most years they are pest #1.

I am in SE Wisconsin. Anyone else noticing they are largely absent this year?

Does anyone know how to kill the cucumber beetle larvae?? Esting the rooys of my watermelon & they are dying