Like all garden pests, Japanese beetles can be a real annoyance in anyone’s yard and trying to find out where their nests are is like trying to find an honest man in Congress – very tricky. Let me guess, you’re wondering where they go at night right..? Let’s find out together:
Table of Contents
Where do Japanese beetles go at night?
Essentially, when the sun goes down the beetles retreat back into their shallow nests which are usually just below ground level. In most cases, these nests are only a few inches deep and you’ll usually find them in long grass or near thick foliage as a good shelter. If you want to find them, these two places are a good place to start.
What Are Japanese Beetles?
Japanese Beetles are a species of small, green, copper, and brown insects native to Japan and other regions of Asia. They can be very invasive and destructive, making them difficult to control. You can find Japanese Beetles in countries all over the world including Canada, Europe, and some parts of Africa.
The scientific name for this garden pest is Popillia japonica and they are a type of scarab beetle. They’re also found in many parts of the U.S and their larvae feed on the roots of turf grasses. Adult beetles are known to attack more than 300 different types of plants, including vegetables, fruits, ornamentals, shade trees, and even field crops.
What do Japanese beetles look like?
As an adult, the Japanese beetle is about a half-inch long with a shiny, metallic green body. They have six legs and two sets of wings. The front set of wings is hard and covers the back set of wings which are used for flying. Usually, around the edge of the hard wing, there is a copper-colored band.
Japanese beetle eggs are tiny and white with a rounded shape. They’re usually found in clusters in the soil near where the female beetle lays them. The larvae (or grubs) are C-shaped, whitish-yellow, and have dark brown heads. They grow to be about an inch long and live in the soil, feeding on different types of roots.
As temperatures start to cool down in late summer, adult Japanese beetles begin to mate. Once they’ve mated, the females lay their eggs in the soil which hatch into larvae within 2 weeks’ time. The larvae then spend the winter underground before emerging as adults the following spring/summer.
Are Japanese beetles invasive?
Unfortunately, yes. Japanese beetles are an invasive species in many parts of the world and their destructive habits make them difficult to control. They’re known to attack more than 300 different types of plants. In some areas, they’ve been known to completely destroy entire crops.
In the United States, Japanese beetles were first introduced in 1916 on a shipment of iris bulbs from Japan. It’s thought that the larvae hitched a ride on the plants and made their way into New Jersey where they quickly spread to other states. Today, they’re found in most of the eastern U.S as well as parts of the Midwest.
When are Japanese beetles most active?
Japanese beetles are most active during the day when it’s warm and sunny outside. They’re less active in cooler temperatures or at night. During the day, they feed on root systems, but they have been known to also feed on leaves, flowers, and fruit. At night, they retreat back to their nests where they rest until morning.
What Time Of The Day Do Japanese Beetles Come Out?
Japanese beetles are most active between 8 am – 4 pm (usually during daylight). This species, in general, prefers to eat and travel during the day, therefore you won’t usually find them at night. Just like you and I, Japanese beetles are the most active during daylight hours and prefer to sleep when it’s dark outside.
What Weather Do Japanese Beetles Like?
Japanese beetles prefer warm weather and are most active when it’s sunny and between 80-85 degrees Fahrenheit. They’re less active in cooler temperatures or at night. Japanese beetles have also been known to feed on leaves, flowers, and fruit during the day.
Do Japanese Beetles Fly?
Yes, Japanese beetles can fly for short distances, usually up to 5 miles with the wind. However, they’re not very good at flying and tend to navigate aimlessly. If you find a Japanese beetle in your home, it’s likely that it flew there by accident or is looking for warmth and shelter.
Can Japanese Beetles Bite?
No, Japanese beetles cannot bite. They have chewing mouthparts that they use to eat leaves, flowers, and fruit. However, they cannot bite humans or other animals because their teeth are too weak to penetrate the skin.
Do Japanese Beetles Carry Diseases?
No, Japanese beetles do not carry any diseases that can be transmitted to humans or other animals. However, their larvae (or grubs) can cause damage to roots which can weaken plants and make them more susceptible to disease.
How Do You Get Rid Of Japanese Beetles?
If you spot Japanese beetles in your garden, it’s vital to act quickly. Fortunately, there are a variety of ways to get rid of these beetles, some of which are rather simple:
- Locate their nests and exterminate them by squishing them by hand
- Set up traps that are designed specifically for Japanese beetles
- Place dead Japanese beetles near high grass or shrubs to deter others
- Make a Japanese insect repellent by crushing the dead beetles and mixing it with vinegar
- Apply pesticides to their nests
- Use African Marigolds
- Use aerating shoes to step on potential nests
- Use nematodes
- Don’t water your grass as regularly
Will Japanese Beetles Ruin My Garden?
If you have a Japanese beetle infestation, unfortunately, your garden will likely sustain damage. As we said earlier, this species eats over 300 plant varieties, so they certainly aren’t fussy when it comes to food. Generally, Japanese beetles will start with grass and move on to bigger plants if left unchecked, so it’s best to stop them early on.
Not managing Japanese beetles could result in some serious problems like damaged foliage, plant loss, and even a full-blown bug infestation. Don’t worry though, a pesticide should be enough to get rid of them.
Who eats Japanese beetles?
There are a variety of predators that eat Japanese beetles, including:
- Ants
- Assassin bugs
- Ground beetles
- Moles
- Raccoons
- Shrews
- Skunks
- Spiders
Will Japanese beetles eat tomato plants?
Yes, Japanese beetles will eat tomato plants. In fact, they’ll eat just about any plant they can sink their teeth into, including:
- Apple trees
- Cherry trees
- Corn
- Grapevines
- Peach trees
- Potato plants
- Rose bushes
- Strawberry plants
When do Japanese beetles die?
Japanese beetles typically live for around 30-45 days. However, their larvae (or grubs) can survive for up to 3 years underground. Once they become adults, Japanese beetles will mate and lay eggs before dying shortly afterwards.
Conclusion
Japanese beetles can be a nuisance in the garden. At night, the beetles go back to their shallow nests that are just below ground. You can find them in long grass or near thick foliage since they provide good shelter. Follow these steps to get rid of Japanese beetles:
- Locate their nests and exterminate them by squishing them by hand
- Set up traps that are designed specifically for Japanese beetles
- Place dead Japanese beetles near high grass or shrubs to deter others
- Make a Japanese insect repellent by crushing the dead beetles and mixing it with vinegar
- Apply pesticides to their nests
- Use African Marigolds
- Use aerating shoes to step on potential nests
- Use nematodes
