With the Japanese beetle invasion in the area and their territory spreading further each year, I checked with local retailers (nurseries, lawn/garden centers, farm stores, Wal-Mart, Ace) to see what they have on hand to hopefully be of help.
First, Please Read the Label on any product before you purchase it to make sure:
1: the product says it controls Japanese beetle adults
2: the product is labeled for where you wish to apply it (vegetables, trees, ornamentals, fruit trees, berries, etc.)
3: follow all pre-harvest intervals (PHI) for when you can safely harvest vegetables, fruits, and berries after a product is applied.
Last year I had to unfortunately tell three people they couldn’t eat the produce from their gardens due to the product they sprayed.
Second, there are a number of insecticide options available. Know that most anything applied to flowering plants will also impact pollinators. For flowering plants like roses, cannas, etc., knocking the beetles off around 7 p.m. in the evening into soapy water will protect pollinators visiting them.
There are also ready to use and concentrate versions of chemicals available. The easiest are ones where you simply attach the garden hose and spray. Others need to be mixed with water into a sprayer.
Organic Insecticide Options include Neem, Pyola, Spinosad Soap, Pyrethrin products (ex. Beetle and Boxelder bug killer), and Bt. Neem may repel more than kill Japanese beetle adults. These products will all last around 3-7 days and will need to be reapplied. Products containing these active ingredients should be safe on fruits, vegetables, in addition to using on flowers, shrubs, and trees. Be sure to read and follow directions as there may be a temperature restriction on applying some of them that contain oils to avoid burning leaf tissue.
Conventional insecticide Options can provide up to two weeks of control. I’m going to separate these into products I found locally based on the location they can be applied. Ultimately, this is NOT a complete list and many other products can also be found online. There are also products containing insecticide + fungicide that I don’t list here. Please be sure to read the label for yourself as to the insects controlled and where it can be applied before purchasing.
1. Ornamental shrubs, plants, trees (like linden, elm, birch): DO NOT use these products on vegetables, fruits, or berries. Hi Yield 38+ and Tempo. There’s home defense products labeled for Japanese beetle adults but they don’t mention they can be applied to trees or shrubs.
2. Vegetables, fruits, ornamentals, shrubs, trees: BioAdvanced Rose and Flower Insect Killer, BioAdvanced Tomato and Vegetable Insect Killer, BioAdvanced Vegetable and Garden Insect Spray, Eight, Spectracide Acre Plus Triazicide Insect Killer, Hi-Yield Lawn/Garden/Pet/Livestock Insect Control, Sevin, Ortho BugClear, and Ortho Bug B Gone.
Many of the conventional insecticide products contain pyrethroids such as bifenthrin or permethrin. Thus, there are also products that just say ‘bifenthrin’ or ‘permethrin’ that can also be purchased. Be sure to read the label as some have restrictions such as “can’t be applied to apples” while others can.