Japanese Beetles Ruining Gardens
By
Residents of Alna and other parts of the state seem to be finding their lawns and gardens at the mercy of a pest that has appeared almost out of nowhere and of which they know little.
It’s the Japanese Beetle (Popillia japonica Newman).
Most people in the area recall first seeing the beetle about three years ago in very trace amounts. The next year there were slightly more, but this year the numbers have exploded.
The damage done by the beetle is being witnessed throughout the state. Jim Dill, Pest Management Specialist for the University of Maine Cooperative Extension, lives in the Bangor area and says the beetles in his yard are “hellacious” and that this is “the worst year in my neighborhood.” He says, “They’re even eating the weeds.”
Residents of Alna share similar feelings. Charles and Lucy Russell have also seen overwhelming numbers of beetles in their yard. Mrs. Russell says that she first saw the Japanese Beetle three years ago in scattered numbers, then more last year and, “This year I was just stunned.”
The damage to their plants has been substantial. Many leaves in their garden have been completely eaten by the beetles so that only a skeleton of the leaf remains.
The Russells looked for advice on the Internet. There they learned that simply collecting the beetles in a bucket of soapy water could be effective.
The best way to do this, according to Dill, is to hold the bucket under the beetle. Its instinct upon seeing a threat is to fall down off of the leaf, thereby landing right in the bucket. The soap will break the surface tension of the water, causing the beetle to sink. Unfortunately for the Russells, the number of beetles was just too overwhelming and collecting by hand was clearly making no progress.
The Russells then decided to get Japanese Beetle traps. The traps are hourglass-shaped plastic bags that hang from pots in the yard. They emit a floral scent or a pheromone to attract the beetle. It travels down the funnel and is trapped in the bottom of the bag.
The Russells have three traps and Mrs. Russell empties the bags once a week. She estimates that, when she does this, there are about 1,000 beetles in each bag. On top of that she continues to go out three or four times a day with a bucket of soapy water and collect beetles by hand. Despite the great numbers of beetles caught, when asked if there has been an improvement she says with great frustration, “No. I really don’t see any difference.”
Where do the beetles keep coming from?
The problem with traps is the scent they release is very strong. It is so strong that it is attracting many more beetles than those just in the trap setter’s yard. It is also attracting beetles from several houses away.
That is why, according to Dill, it is best to use traps on a neighborhood wide scale. Mrs. Russell collects 1,000 beetles per week in each trap Dill says, “If everybody was collecting 1,000 beetles a week you’d start making progress.”
Unfortunately, Dill also says that it is, now, too late in the season for traps to be effective. When using traps the goal is to have them out early enough in the season so as to get the adult beetles before they begin mating again and laying eggs. Now the eggs are already laid and the adults will continue to feed on the foliage for the remainder of the summer.
However, it is still possible to treat the lawn for grubs. Dill says that the Extension, this year, has been recommending a type of parasite called a nematode to be put on lawns. It is a small worm that specifically eats grubs. The time to do this is late August or early spring and, once again, Dill says, “To get the best control, the wider the scale, the better off you are.”
Nematodes provide effective treatment for the lawn and, as they are living organisms, it is an organic solution. There are no chemical pesticides, which could be harmful, involved in their use.
The Japanese Beetle was first discovered in the United States in a greenhouse in New Jersey in 1916. In the U.S. the beetle found an environment abundant in food but lacking its natural predators, it has therefore been able to reproduce at staggering rates almost without interference.
The beetle has only a one-year life cycle. In early summer the female lays about 40-60 eggs in the soil beneath the grass. These eggs hatch around midsummer and the grubs feed on the roots of grass. With the coming of fall, the grubs burrow down beneath the frost line and remain there all winter. As the ground thaws, the grubs come back up further to feed on the grass roots. They change into pupae and two weeks after they emerge from the ground as adult beetles.
These new adult beetles then begin a new cycle of feeding on foliage and laying eggs. Without any other species to prey on either the adult beetles or grubs, they have been allowed to increase at exponential rates.
According to the United States Department of Agriculture’s (USDA) web site on the pest, “No quick fix can rid homeowners of the Japanese beetle once it becomes establishes.”
Most non-profit agencies such as university extensions agree that significant and lasting improvements require and extended, community-wide effort. An individual can rid his or her yard of grubs but if they are growing in surrounding yard there will still be numerous adults to feed on the foliage and flowers of plants.
After treating the lawn, the remaining adult beetles must then be dealt with. And, according to Dill, “There’s not a lot to do for foliage organically.” This leaves either handpicking or spraying with some kind of pesticide.
He says, “If you have one rose bush you can handpick and keep pretty well ahead of them” But most people in the area have considerably more than one or two plants to protect.
The Morris Farm in Wiscasset uses an entirely organic approach. According to Jeff Burchstead, they spray their plants with what he calls a “garlic beer,” a fermented garlic solution. The farm has not yet seen any real sign of Japanese Beetles except for some slight eating of been plant leaves.
That does not necessarily mean the garlic beer is keeping them away. According to Dill, “Garlic spray may do some repelling. I’ve never seen anything specifically for the Japanese Beetle (saying that garlic spray works), but that doesn’t mean that it doesn’t.” But he says, usually, “If you don’t want to use insecticide the adults are really quite difficult to control.”
For people who want to try using insecticides, the extension service gives individual consultations to determine what kind of spray and how much is necessary. Residents affected by the Japanese Beetle would be much better off simply calling the extension service, rather than trying to find pesticides themselves, and extension service spokeswoman said.
There are many articles on the Internet offering advice. However, many are attached to some kind of online business. Therefore, the solutions recommended will be limited to those company sells.
The UMaine
Cooperative Extension Service can be reached at 1-800-244-2104. The Morris Farm
is located on the
MRS Reference for