Japanese Beetles are one of the most hated lawn pests.  This is because they are ravenous eaters, and they affect the lawn and garden during virtually every stage of their life cycle.  To effectively control Japanese Beetles in your lawn and garden, you need to understand their life cycle.  Then, you must know what works and what doesn't for control.  You might be surprised at what constitutes effective Japanese Beetle Control.

Life Cycle of the Japanese Beetle

Japanese beetles spend part of their life cycle above ground and part of their life cycle below ground.  They cause damage during both parts of their life cycle.  The grubs attract small mammals that tunnel and dig up the lawn to get to the grubs.  The adults eat almost everything, but particularly love to eat the leaves of roses.  The insects are most vulnerable and susceptible to control when they are young grubs feeding near the surface of the soil in July or August.  You can also somewhat control the adult populations, but there are some commonly used methods that do not actually work.

Japanese Beetle Control: What works and what doesn't

You've probably seen pheromone traps in the garden center.  They advertise to kill thousands of beetles!  This is certainly true. . . however in order to kill thousands, these traps lure every beetle within the nearby area to your yard.  You might catch a lot of Japanese beetles, but you probably aren't doing much to reduce their overall population.  The most effective use of these traps is to convince your neighbor to put one up in their yard--better yet, convince your neighbor five houses down, across the street to do this.  Let them lure all of the beetles away from your garden!  Our advice:  stay away from these traps. One effective way to control Japanese beetles, if the adult population isn't overwhelming, is to hand-pick them off your plants, or to vacuum them with a hand vacuum.  Drop them in soap water to kill them. Plant things in your yard and garden that Japanese beetles don't like to eat.  They really enjoy munching on hollyhocks,  roses, corn,  and fruit trees.  they are much less interested in Four-o-clocks, larkspur, geraniums, calladium, forget-me-not, coralbells, cornflower and others. Apply Milky Spore to the yard and then refrain from using lawn insecticides for a couple of years while the milky spore builds up.  This is a bacterial disease that infects and kills the grubs. Treat the lawn with beneficial nematodes.  It is important to do this at the right time to have the most effect--in late July or early August.  Water the lawn before and after you add the nematodes. As with all pest and disease problems, decide whether you have a problem bad enough to treat before spending the money or time on treatment.  if the problem is not out of control, you can leave it alone.  All pest populations will eventually self-regulate.  When the populations become too large to sustain themselves, the population will crash, and you will enjoy a few relatively pest-free years.