It's war! Me versus Japanese beetles

    

This bowl is full of dead, or dying, Japanese beetles, plucked off the driveway.

Gloves and two bowls of Japanese beetles, dunked in warm, soapy water.

    It's a good thing I appreciate a challenge: Japanese beetles provide one like none other this time of year.

    Many gardeners are currently fighting the beetles and I am among them.

    The local beetles love to eat the leaves of the giant Linden trees that line our driveway. After they fill themselves with leaves they drop to the concrete, where I am often waiting to pop them into a bowl filled with hot, soapy water. 

    If I don't catch them they threaten the beautiful flowers in the annual garden, steps away.

    The American Linden trees are gorgeous, normally, and they were purchased before the beetles arrived in Eastern Iowa several years ago.

    The bugs are a menace, mainly as they have no real predators in the United States. In the grub stage Japanese beetles are one of the most egregious yard-killers in the Upper Midwest. They attack a wide variety of plants, even corn and soybeans in Iowa. Farmers spray pesticides to control them.

    Spraying the Linden trees is not logical: They are taller than our three-story house.

    Adult beetles show up the end of June or first of July in Iowa and stay until August or September. It's the air temperature that ultimately stops the carnage.

    Japanese beetles were first found in the United States in 1916, in New Jersey. The larvae arrived on a shipment of bulbs. In Japan, the beetles have natural predators, the USDA reports. Most states east of the Mississippi River were first infested, but the beetles have by now spread to Iowa, of course, as well as Minnesota, Missouri, Nebraska, North Dakota and other western locales.

    This year, my plan is to kill as many in the driveway as possible. I blow debris off the concrete so I can see the beetles clearly and then snatch them up and dump them.

    In the past, without forethought, I've done this task without gloves. Never again. These little guys have big months and they bite.

    I can stand in the driveway and hear the bugs as they drop from the trees. This week they are dropping at an alarming rate. I hope that if I can keep up for several days, the incidence rate will drop. The beetles move slowly in the early-morning hours; another good time to catch them is late afternoon.

    If I don't nab them they will ultimately destroy numerous flowers, and infiltrate the house. 

    While dumping them to drown in soapy water is widely recommended, there are other ways to treat the bugs:

    1. A neighbor has a few calla lilies, which the beetles love. She explains the lilies are sacrifices in the fight against them.

    2. A friend has a spray bottle of insecticide to use, and such products are available in garden centers. Be sure to ask for options that don't harm the bees, or pollinators however!

    3. Some people use "beetle traps," but experts believe these traps actually attract more beetles to the yard and that's why I've avoided investing in one.

    The Extension Service at the University of Wisconsin lists five ways to fight the beetles without hurting pollinators. These include:

    1. Bacillus thuringiensis, or Bt: Bt galleria is an ingredient that can be purchased from garden retailers. A variation of this, Bt Aizawi, is not friendly to pollinators, according to the article, "5 Ways to battle Japanese beetles while protecting pollinators," by Vijai Pandian, of the university's Extension Service. It is online: wiscontext.org

    2. Acelepryn is a new insecticide that provides good control of the beetles when the product is sprayed on the leaves of affected plants. It is suggested it be used only on ornamental plants, however. (It would be impractical to spray this product on tall trees, unfortunately.)

    3. On fruits and vegetables, the article suggests using organic products like neem oil or spinosad. These are sprayed at night after most pollinator activity has paused for the day.

    4. Small landscape plants can be protected using nylon insect screens. I've never seen these before but will be looking into buying two, next year!

    5. The final suggestion is to use a product like Acelepryn on flowering lawn weeds, such as clover. A light irrigation is suggested after application to allow the insecticide to leach into the thatch layer. This would work on the beetles in the larval stages.

    Gardeners who also are fighting these stubborn beetles will hopefully find some good ideas in these suggestions. Here's hoping for a frigid February, 2022, to keep the beetle numbers down.