Mark: Any JB's hit with a spray of Sevin will be moving in only one direction, and that is straight down to the ground. Sevin has great knockdown power for JB's, but, unfortunately, little residual effect. So it's best to wait for a buildup on their favorite plants, then hit them when there are large numbers present. JB's do like raspberries, but I have never seen them on strawberries or tomatoes. My son has a purple leaf decorative plum that was severely infested 3 years ago. I gave it a thorough spraying with Sevin, and it literally rained beetles for the next 10 minutes. I subsequently treated his property -- 3 acres -- with only one 44 ounce can of milky spore, and he has not had beetles since. This was way below the recommended application rate, but that one can of pure spore was apparently enough to infect the numerous grubs in his soil and he now has total control. I spread the spore very thinly with the tube applicator on about a 10 foot grid. It took me several hours to walk his property and make the application. Milky spore is also sold in a mix intended for application by broadcast spreaders, but this product is quite low in the percentage of pure spore, and ends up being considerably more expensive for what you get. It is, however, easier to apply. Don Yellman, Great Falls, VA

Terryjean, Back when my part of the world had rainy summers, I could count of JBs from the first week of June through August and into early September. When people would come on here and say that the JBs would only damage one bloom cycle of roses and I knew they could take out two. Drought for three years running after using traps for the past eight years has removed my problem. Drought (according to the local extension servie) in Mid March here will entomb them. But when conditions are favorable, the JBs extend their time range as well as their geographic range, to all our detriment.

Here is some interesting information about Japanese Beetle control from Prof. Daniel A. Potter of the University of Kentucky Department of Agriculture. I have corresponded with this professor, after finding one of his earlier articles about Japanese Beetles on the web, and he has been kind enough to summarize some research results that will probably be published within the next year. I mentioned to Prof. Potter that I would forward his comments to Gardenweb.com. First, here is my summary: several different "conventional" and organic insecticides and repellents, which are advertised to reduce JB damage to plants, were tested by applying the products to linden tree foliage (one of JB's most favorite foods), "weathering" the treated foliage outdoors for varying time intervals of 1,3,7,14,19 days (to test durability of each product when exposed to the elements including rain), and then offering the treated and "weathered" foliage to JBs. Some of the more effective products, from longest to shortest lasting, were: 1. Synthetic pyrethroids (deltamethrin, bifenthrin, lambda-cyhalothrin, permethrin, and cyfluthrin): all gave effective protection for more than 19 days. (I don't yet have the trade names in these products, or any information about the "inert" ingredients that are mixed with the pyrethroids.) 2. Sevin: protected for about 14 days 3. "Pyola" from Gardens Alive, natural (botanically derived) pyrethrins in a canola oil base, the most effective organic product: protected for about 5 days 4. "Neem-away" from Gardens Alive, neem oil product, protected for about 2 days During the protected time span, JBs will not feed (or will not survive an attempt to feed) even when put right next to the "target" foliage. If, as other research suggests, JBs tend to follow a "feeding trail" marked by the pheromone scent of other JBs, it may be that JBs will not return in force to a protected plant (or garden) for some period of time even after the repellent wears off. Such an after-effect was not tested in the study. Here now is the complete letter from Prof. Potter: ############################################################ Last summer one of my students evaluated a number of "organic" insecticides, as well as known or putative feeding deterrents for repellence or direct control of adult Japanese beetles on linden foliage. We sprayed individual intact linden shoots, allowed the residues to weather outdoors for varying 1, 3, 7, 14, or 19 d, and then harvested those shoots and challenged them in "no-choice tests" with 10 beetles confined with a treated or untreated leaf, or in "choice tests" wherein 10 beetles are offered a treated versus untreated leaf in an arena. We tested five synthetic pyrethroids (active ingredients were deltamethrin, bifenthrin, lambda-cyhalothrin, permethrin, cyfluthrin) and all of them gave at least 19 days residual control from a single application, despite frequent and heavy rains. Sevin gave about 2 wks protection (longer than I would have thought), but did not last as long as the pyrethoids. Among the "homeowner-oriented organic products", the most effective were "Pyola" and "Neem-Away", both from Gardens Alive. Pyola is a combo of natural pyrethrins plus canola oil; it was effective out to 3 days, but not to 7 days post-spray. Pyola also was relatively rain-fast once the residues had dried. Pyola served as a feeding deterrent, and also gave rapid knockdown, although most of the exposed beetles eventually recovered in these lab assays. I think they would dessicate and perish in the field. One day old residues of Neem-Away were highly deterrent and gave good protection, but the effect noticeably was wearing off by 3 days, and the product seemed less rain-fast than Pyola. Surround is a kaolin clay based emulsion that is sprayed on plant material to deter insects. It essentially whitewashes the plant material with a fine film of inert white clay. In our trials, surprisingly it did not deter the beetles from eating the linden foliage. Regardless, I don't think that Surround is well suited to use on roses or other flowering ornamentals because the white coating affects aesthetics. But it does have promise for fruit protection, where the clay residues can be washed from the fruit after harvest. We are also looking at Surround as a borer treatment (i.e., whitewashing tree trunks). Keep in mind that these were one set of experiments on one plant species (linden), so results might differ on other plants. For example, we did not apply them to open rose blooms. But from what we saw, either Pyola or Neem-Away should give short-term residual protection and be effective if re-applied as-needed (every few days) during the period when Japanese beetles are abundant. Of course, neither will protect rose blooms that break bud and open "in between" sprays. Several of the "natural" plant extract-based products that we tested (and that claim efficacy against Japanese beetles) caused severe phytotoxicity (burned the leaves), so growers would be well advised to test such products on one or two plants before treating a whole garden. As I am 100% Research and Teaching, I regret that I'm unable to answer all requests from the many individual gardeners who find me on the Web or telephone. We will be publishing this work in both scientific and popular articles, but probably not until sometime later in 2005. Also, we may be doing additional testing on roses. Feel free to follow up later on. Incidentally, there is a good Fact Sheet on Japanese beetle management that can be downloaded for free from the University of Kentucky Department of Entomology website. Hope that helps. Regards, Dan Potter ############################################################

Hi All! I have several raised beds and one has Canna and Four O'clocks. When the Jap' beetles arrived just over a week ago I began picking them off. At first first there were only 5 or 10. Then last weekend the amounts began to grow slightly. It was the first real beetle infestation I've had since we moved here 4 years ago. I had a metal Jap' beetle catcher from way back, along with a can of scent. I hung it in the middle of the bed on Monday eve. On Tuesday morning before leaving for out of town, I went to check to see if it was catching. I couldn't believe it. Without to much exaggeration there must have been 500 in the small 4 X 8 area. The pungent scent on Tuesdas hot humid morning must have drawn them to the catcher, with a quick stopover to the plants, from all of my neighborhood, and there was only 1 or 2 inside the catcher. Boy what a screw up that was. Well it's taken me almost a week of picking and drowning to get it under control. I began culling off all the hundreds of leaves they destroyed over the weekend. I had 1 beautiful Hollyhock in the bed that I left that came up from seed. All that's left are the Maroon blooms. I'm going to leave it to see how resilient a plant can be. Last year we had a Maple tree that was infested with the small inch caterpillar and I swear I was going to cut the tree down as we couldn't even use the hot-tub because of the droppings. I'm not that heartless so I'm leaving the Hollyhock as is because I swear the tree has come back stronger than ever. Of course the Holly won't have that chance for next year. But isn't Nature amazing? Jim