The Japanese Beetle is a shiny, metallic green/coppery hungry little bug! Some would say it is actually pretty. This is only until they see the damage they can do in just one day. Early spring is the time to apply some type of treatment before they hatch out. Control them before they have destroyed your entire garden or landscape. Let me tell you a little about their habits, life cycle and safe removal. It would be wonderful if everyone would treat for them before the grub turns into the beetle. Then all our hard work and beautiful gardens will shine instead of this pretty little beetle.
Habits of Adult Beetles
The beetles begin to emerge from the ground and start feeding on plants in mid-June. This does depend on our spring weather and how fast the ground warms up.They do most of their damage over a 4 to 6 week period. Japanese beetles feed on about 300 species of plants. They have their own little army that enjoys feeding in groups which causes the most damage. One single beetle doesn’t eat that much. They starting at the top of a plant and work their way down. The beetles especially love plants that are in direct sunlight.
When the beetles hatch out, they start mating. The female lays her eggs immediately. They leave plants in the afternoon, to find an area that suits them, then burrow 2 to 3 inches into the soil and lay their eggs. She may lay as many as 40 to 60 eggs during her life. Females are attracted to moist, grassy areas to lay their eggs. Golf courses sometimes have higher grub populations, especially if they irrigate often. Many beetles overwinter in the grub stage. When the soil cools to about 60°F in the fall, the grubs begin to move deeper. Most live in the winter 2 to 6 inches below the surface, sometimes more.When soil starts warming up above 50°F in the spring, the grubs begin to move up into the root zone.
The grubs feed on the roots of grass and can eat a plant's entire root system. You may have a patch of pale, discolored and dying grass that may look a little like drought stress. The damaged areas grow larger as the grubs expand their feeding range. Grass will feel "spongy" when you walk on it and you can easily lift it off. If you see raccoons, moles, skunks or lots of birds in the yard, you might have a grub infestation.
One of the easiest ways to rid your plants of the beetles is to hand pick them. I personally have a hard time doing this. I must put my gloves on. This is best done before they start getting to numerous. If there is just one beetle on a plant their army will follow. Shaking them off early in the morning helps, they are a bit sluggish at this time. Use a bucket of soapy water to drop them into.
There are natural and organic treatments as well as chemical. Here is a few natural controls.
The active ingredient Bacillus popilliae,in Milky Spore Powder is a naturally occurring host specific bacterium that kills Japanese Beetles in the grub stage. Once grubs ingest Milky Spore, they die within 7 to 21 days. When eaten, the spore is activated, as the grub decomposes, billions of new spores are released into the soil. Milky Spore in the soil is not harmful to beneficial insects, birds, bees, pets or man. The Bacillus popilliae spores continue to reproduce and spread naturally to control larvae in the area for 15 to 20 years.
Veggie Pharm is a mix of natural ingredients like cottonseed oil, garlic and peppermint. This is a contact spray. I have used this on my pole bean plants, porcelain vine, wild grape vines and it worked very well. You do need to be careful that you spray early in the morning or late afternoon when the beneficial insects are sleeping. Always read labels carefully.
Japanese Beetle Traps
These traps attract the beetles with two types of baits. One with the scent of the female. The other one is a sweet-smelling food-type lure that attracts both sexes. This combination draws in thousands of beetles in a day. Unfortunately, research has shown that the traps may attract more beetles than are actually caught. If using traps, be sure to place them well away from gardens and landscape plants.
Your favorite plants such as roses can be protected by covering them with fine garden cloth during the peak of beetle season. They don't have to win!