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Japanese Beetles
The Japanese Beetles are back. Usually appearing in late June, we have actually already had reports of a few early ones this year. And while they have been feeding voraciously already, there are still several weeks to go of their damaging presence, possibly well into July. The adult beetles eat the leaves and flowers of over 300 plants by eating the tissue between the veins. The larvae, called white grubs, feed on plant roots and organic matter in the soil, especially under turfgrass. This feeding may result in dead patches of turf that can be picked up like a loose carpet. There are several approaches to controlling the beetles and their larvae, and the damage they do: it is most important to understand that the first, scattered beetles you see are scouts. Once they have found promising feeding grounds, they release a scent to attract all the later emerging beetles to the area. Get rid of these scouts and you could have considerably less of the beetles this season. To learn about the control options, click "continue reading"
Adult Beetle Control: 1. Watch closely for the first adults to arrive, pick them off, and drop in soapy water. You can prevent them from sending out the message to the later beetles! 2. Plant Non-Attractive plants. (Partial list here.) 3. Trapping: Traps with a floral lure and sex attractant are available (we carry the Bonide brand) and attract the beetles and trap them in a bag for disposal. In most circumstances, however, they can do more harm than good by bringing MORE beetles to the area than would have been there otherwise. 4. Insecticides: Spray susceptible plants with carbaryl (Sevin) or pyrethrum (Bonide Japanese Beetle Killer) every 5-10 days. Bayer Advanced Tree and Shrub Concentrate (imidacloprid) is a systemic that is watered into the soil, but must be applied 20 days before insects appear to be fully effective. Grub Control: It is important to note before applying chemicals that the presence of Japanese Beetles does not necessarily mean you have/will have grubs. The beetles may love your food sources, but prefer someone elses lawn for their precious baby grubs. Always check for lawn damage and grubs before applying chemicals unnecessarily. 1. Insecticides: Grubs are best controlled when they are small and actively feeding, late July and August. Imidacloprid (Merit) and halofenozide (MACH2), applications in June and July have sufficient residual activity to kill the new grubs as they come to the soil surface in late July through August. DYLOX can be used later, but is not as effective as earlier applications as grubs are larger and may not be feeding. 2. Biological Controls: Nematodes and bacterial Milky diseases (Milky Spore) have been effective in parts of the country, but have not been well-proven in Ohio and Kentucky. Milky Spore also requires several years of application before it becomes effective. (Information adapted from \"Control of Japanese Beetle Adults and Grubs in Home Lawns\" HYG-2001-03 David J. Shetlar Extension Landscape Entomologist The Ohio State University)