Japanese beetles?
Question:I was reading that they don't like the smell of garlic, so I made a paste out of about 30 bulbs of garlic and water and sprinkled it all over my bushes.
I do realize that I should plant garlic near them, but will this help for now until I can plant them?
Answers:
The advocacy of garlic oil as a Japanese Beetle repellent is based on questionable data at best. I can find no credible scientific evidence in support of these claims nor do the people who advocate such a control method provide credible scientific source(s) to backup their claims. In fact, I can only find information in the university extension services questioning or disproving the efficacy of garlic oil. As an example, Cornell University's web site published results of a study involving the use of Garlic Oil sprays on apple crops. Their conclusion is as follows:
..."Results showed that the garlic spray applied at a rate of 11 oz/A did not provide control of any of the labeled apple arthropod pests in N.Y. and did not affect the population density of two predator species commonly found in apples. The foliar pests - aphids, leafminers and mites - were unaffected by the garlic sprays. The fruit pests - plum curculio, tarnished plant bug, obliquebanded leafroller and internal lepidopterans - were also not affected by the biweekly sprays. "
The Virginia Cooperative Extension Service writes: ..."Repellent sprays, such as garlic sprays and bug sprays (made from a puree of bugs), have been found useful by some gardeners, but their effectiveness is questionable."
I appluad the search for viable, non-toxic or low-toxic alternatives to the control of insects and diseases, but giving false hope that these products are safe & effective without supporting evidence is counter productive to your cause. I can only recommend caution in applying any of these methods at this time.
Also, liquid detergents can be phytotoxic to your plants. They work by removing the protective wax coating from the exoskeleton of an insect, but they also remove the protective wax coating from your ornamental plant's leaves. Always test a spray made with liquid detergent on a couple of leaves before general use on your plants. The Clemson Extension Service writes about soaps: "Homemade soap recipes are not recommended because they are more likely to cause foliage burn. Commercial insecticidal soaps are tested on plants and are less likely to cause damage."
Vegetable oils can also harm your plants. Applying vegetable oil at too high a concentration, when plants are in need of moisture, or when temperatures are greater than 90 degrees can damage your plants. Remember that vegetable oil will accumulate on leaves when used repetatively as a contact insecticide. These accumulations could create localized concentrations that reach phytotoxic levels.
These links show the potential danger seemingly harmless home remedies can create. Please be careful.
http://answers.yahoo.com/question/index;...
http://answers.yahoo.com/question/index;...
The following is a reprint from Michigan State University: "The major problem caused by adult Japanese beetle in the home setting is the feeding on ornamental plants. Sevin (carbaryl) and Malathion (acephate) are available for over the counter purchase by the general public. Unfortunately, in heavy infestations it may be necessary to treat sensitive plants on a 5-7 day schedule in July and early August. Follow the label instructions for rates as using more than what the label calls for can cause damage to the plants."
The University of Arkansas recommends the following: "For organic growers, Rotenone and pyrethrins provide some benefit, but they are not highly effective... The notes that Danitol and Sevin work best against these beetles. Imidan, malathion and Marlate (methoxychlor) are moderately effective. "
Anne,
I personally use Bayer Advanced Rose & Shrub Care. This is an insecticide systemic that is applied around May 1st. You mix it with water and pour it on the shrub roots. The roots absorb the active ingredient (imidicloprid) and translocate it to the leaves. It take two months to move the AI to the leaves which is why you apply in May. Now the insecticide only kills those insects that consume your shrubs leaves. The University of Illinois Extension Service has reported some interesting findings. If you can prevent Japaense Beetles from consuming your shrubs in the first wave, they baiscally leave your plants alone for the rest of the season. It seems that they like to feed on shrubs already damaged by other Japanese Beetles. Imidacloprid defends your shrubs during the first wave. It is affective. Now, imidacloprid is not going to help you right now. Sevin is the best product I have used when I have not used imidacloprid. It does need to be reapplied after a rain, but it kills Japanese Beetles on contact and you do not have to run outside with your contact sprays every hour shooting the new Jap Beetles.
Controling Jap Beetle when its a grub never will work. They can fly over 2 miles. Everyone within a 2 mile radius must do this to affect the number of Jap Beetles that can reach your yard. Don't get me wrong, if you have sufficient Jap Beetles in your lawn to warrant control, then control. The threshold is usually 12 beetles per square inch. Above this threshold they do enough damage to your lawn that your lawn can not out grow the damage. Below this threshold & you will not know they are there. Use milky spore, nematodes, or imidacloprid. They all work, but timing is important. They also all need to be watered in to work. And that means a lot of water. lol
It should work! It is thought that it confuses the beetle from its prey.
It has worked for some people.Someone on the gardenweb forum found a garlic-flavored olive oil spray in their cupboard and lightly sprayed their basil plants with it, & it got rid of the beetles.
Here's a Garlic spray you can try:
Use up two cloves of garlic and a hot pepper in a pint of water. Strain, add a drop each of liquid Ivory soap and vegetable oil & spray on plants early in the morning.
Aim at the beetles & try to coat them because the oil will smother them.
When I don't have a spray handy I flick them into a bowl of soapy or oily water.
Another procedure is to spray a mixture of 1 tablespoon isopropyl alcohol to a pint of pyrethrin mixture. Don't use in full sun or high temperatures because that's when they can burn or stress plants. Always aim for the beetles, not the bush.
Long-term prevention for Japanese Beetles is biological controls such as beneficial nematodes or a product called "milky spore," which attack the grubs, and prevent recurrence for years.
Rotenone, Pyrethrum, Diazinon and Sevin sprays are also effective against adult beetles.
Besides garlic, you can plant white mums, rue, tansy, larkspur, and citronella, that are known to actively repel the adults.
Especially on hardy bushes & shrubs, you can always Vaccuum those beetles up ...if you don't want to use chemicals or sprays! LOL
Good luck!
Looks like you've done the right thing but commercial garlic sprays like Liquid Fence might do the trick as well.
I don't think the odor from plants would be strong enough because you don't really smell the plant unless parts of it are crushed.
Thought you might enjoy the article I've referenced below on japanese beetle control.without pesticides
It doesn't work in my garden. I have a gazillion garlic plants all around my garden and I still have an invasion of Japanese Beetles.
"Sevin" powder is the only thing that gets rid of them for me.
Yes and I check my plants each day and flick them off into a coffee can with Dawn dish detergent. Kills them instantly.
They love Rose bushes and will destroy the buds if you don't treat the bush.
I've been gardening for a long time and am still learning...
The best way to get rid of Japanese Beetles is with Milky Spore. The trouble with Milky Spore is that it doesn't' work instantly so keep trying your home remedies in the mean time but it works by giving the beetles a virus that spreads to other beetles, through out many years. I used it about 20 years ago and reapplied it again about 5 years ago and it is amazing the reduction of the beetles. I barely have any now. You have to spread it around your lawn and water it in but that is it. It really works and can be bought in Home Depot or Lowe's. The trouble with Sevin is that it may work but Sevin also kills bees... no bees, no flowers.
More Related Questions & Answers...