Just like most other pests and critters in your garden, Japanese beetles can be a real issue in more ways than one. If you have been spotting these little insects during the day, and find them suddenly disappearing later, you might be wondering- where do Japanese beetles go at night, and should you be worried about them.
Well, here's your ultimate guide to just that.
Scroll down to get a detailed overview of everything you need to know about Japanese beetles, where do they go at night, how they can affect your plants, what you can do about them and much more.
What are Japanese Beetles?
Native to Japan and other regions of Asia, the Japanese Beetle is a tiny green, copper and brown, and, wait-for-it, invasive insect. They resemble scarabs, and are highly adaptable, which makes them quite tough to deal with.
These beetles may exist in various regions of the globe including Canada, Europe and some African regions.
Scientifically called Popillia Japonica, Japanese beetles, if left unattended, can wreak havoc in your garden and can destroy garden plants, flowering plants, and trees.
How Do I Identify a Japanese Beetle?
Japanese beetles bugs are beautiful but destructive. Adult beetles are around 3 inches in length and have a metallic-green head.
Their wings are copper colored, and if you look closely, you should be able to see five white spots of hair at the side of the abdomen.
Younger beetles and larva are white to cream colored, with a brownish head.
How Do I Know if My Plants Have Been Invaded by the Japanese Beetles?
Japanese beetles tend to chew the leaf tissue between the veins of leaves. If you spot tiny holes in the leaves of your plants, usually between the veins, it can be a sign that your plants have been invaded by these beetle species.
If you have a lawn that seems to have brown patches, look closely and you might find these beetles there. These beetles damage the grass roots, leading to the brown patches which are distinctly visible.
What Time of the Day are Japanese Beetles Most Active?
Japanese beetles tend to appear and be active from 8 am to 4 pm- the hours when there is daylight.
These beetles like to work and go in search of food during the day. It is very rare that you'll spot one during the night.
Nighttime is when they travel into their underground nests and sleep. The nest of Japanese beetles is usually hidden under a protective vegetation cover.
Are Japanese Beetles Active During the Day?
Yes, Japanese beetles feed the most during the early hours of the day between 8 am to 4 pm. They also prefer the warm weather and their activity generally decreases in the cooler months of the year.
Adult beetles can fly on a cloudy day and seek refuge on windy nights.
What Weather do Adult Japanese Beetles Like?
Japanese beetles can be found at any time of the year and in plants and ponds in spring and fall from early summer.
The warmer the environment, the more the Japanese beetles population you can expect to find- they are actually a summer species that are most active during the months ranging from early July to mid August, where the humidity levels are high.
In the colder months of the year, the adult Japanese beetle die. This is because their life span is usually around 60 days, which means the summer bugs have already crossed their life span by the time they reach winter.
When the frost hits the ground, the grubs move deeper into the ground and burrow deeper into the ground. Japanese beetles are strong, and can survive until the temperature drops to 15 degrees Fahrenheit.
Yes. When the temperature goes below 15 degrees Fahrenheit, the Japanese beetle grubs can die.
Are Japanese Beetles Active at Night?
If you're wondering where do Japanese beetles go at night, you're not alone. Well, it is during this time of the day that they retire to their nighttime nesting location in their shallow nests.
These beetles are more active during the daytime, which is why, it can be hard to find them during the later hours of the night.
You might find a few during the sunset, but as the night sets in, a typical Japanese beetle will return to its underground nest and retire for the day, much like humans.
How Long Do Japanese Beetles Live?
An adult Japanese beetle can live for up to 6o days. An adult beetle usually lives for 30-45 days, whereas the larvae or the grub, can survive for up to 3 years, if they are in their underground nest.
Are Japanese Beetles Invasive?
Yes. Japanese beetles are invasive and the USDA officials claim they are very destructive and are a threat to US agriculture.
Since their discovery in 1916, the beetles are now spreading rapidly. Thankfully, the strict regulatory regime and rigorous controls have prevented their establishment.
Scientists, however are now concerned that global warming might affect beetle populations. This means that there is a good chance these invasive species could expand north into Canada.
How Do I Deal with a Japanese Beetle Infestation?
If your garden has been hit by a Japanese beetle infestation, there are a few ideas you could implement to get rid of them.
Remember that to control the Japanese beetle population, time is of essence, and the faster you act, the easier it can be to get rid of Japanese beetles.
How Can I Control Japanese Beetle Populations in My Garden?
Using a Japanese beetle insect repellent is the best way to control their population, and keep them from invading your garden. You can find many different variants online and pick the one you like best for your garden.
In most cases, you can find Japanese beetle nests near the area of the infestation and the affected plants, and the simplest way to keep them from spreading is to manually remove this nest. You can hand pick the adult beetles and place them in a can of soapy water to control their spread.
Another effective way to get rid of Japanese beetles is to set up a trap crop like African marigold, or simply use Japanese beetle traps.
Japanese beetles are also very attracted to Geranium plants. Then, when they consume these blossoms, they become dizzy due to the natural chemicals in the plant and eventually fall off, which makes them easy to be removed manually.
You can plant geraniums near your valuable plants as a method of pest control of this invasive species.
If you have spotted Japanese beetle larvae or adult Japanese beetles in your garden, it is most likely that your garden will sustain damage.
Since these beetles consume most plant species and aren't really fussy when it comes to food, you might need to take quick action to ensure grub control and protect your garden from Japanese beetle damage.
Remember that these beetle species first start to eat grass roots and then move on to attack other plants.
Other Tips and Tricks to Get Rid of This Beetle Species
Still wondering what makes Japanese beetles go away from your garden, and if there are any other ways to get rid of Japanese beetles once and for all? Here are a few other good tips and tricks you might want to implement.
- Rely on natural predators like skunks, racoons, moles, ants, ground beetles and spiders. A lot of these eat Japanese beetles and can be really helpful in establishing natural pest control.
- If you have crops that do not need to be pollinated, installing row covers is a great idea. You can install these covers during the 8 week feeding period around mid June, which can help keep the pests away from your garden.
- Another effective way to keep the adult female beetles from feeding on your plants is to spray a bit of neem oil on your plants. The use of neem oil helps prevent the second generation of Japanese beetles from emerging, and helps control their population.
- You can also consider spraying beneficial nematodes through your garden. The use of these parasitic nematodes can be particularly helpful in establishing grub control.
- Some experts swear by another technique, which is using dead Japanese beetles to control their population. You can place a few dead Japanese beetles near their nests and your plant roots to encourage them to go away.
- You can also spray the target plants with a simple homemade solution of dishwashing liquid, water and oil. Remember that this soapy water solution can be effective only for a certain period of time, and can be applied only to certain plants.