Japanese beetles are an invasive species and a major pest of over 300 plant species in the United States. Needless to say, you don’t want these bugs in your backyard – but is there anything you can do to discourage them?
Several mammal, bird, and insect species are known to eat Japanese beetles. By encouraging their presence around your home, you can reduce the number of Japanese beetles on your property and, therefore, the amount of damage inflicted on your plants!
What is a Japanese beetle?
The Japanese beetle is an invasive species, but one that is well established in the United States. This insect first arrived in the USA back in 1916 and, since then, has become widespread throughout the eastern states.
Unfortunately, Japanese beetles are serious agricultural pests and can cause massive damage to flowers, trees, shrubs, fruits, vegetables, and turf. Adult beetles have an enormously varied diet and feed on over 300 plant species. They chomp their way through the leaves, flowers, and fruits of virtually every plant they come across and, in large numbers, can decimate your garden.
Their larvae aren’t innocent, either, and can destroy the roots of grasses. This prevents the grass from effectively taking up water and nutrients and, in cases of severe infestation, can lead to large dead patches of turf on your lawn.
How to identify Japanese beetles
Japanese beetles are quite easy to spot, thanks to their striking colors.
Adult beetles are metallic green with coppery wing covers and have a pretty, iridescent sheen. Below the wing covers, they have a row of white dots that run along each side of the abdomen, and which are made of patches of white hairs. Japanese beetles are stocky and quite large, reaching up to ½ an inch in length.
What eats Japanese beetles?
Japanese beetles are a nuisance but, fortunately, they have a lot of natural predators. Japanese beetle predators include a variety of bird, spider, and insect species, many of which are common in the United States.
Tachinid flies are a family of parasitic fly, with around 1500 species found all over the world. They can look a lot like plain old house flies, but the behavior of the Tachinid fly is actually very different. Tachinid flies parasitize a wide range of insects, including grasshoppers, caterpillars, sawfly larvae, earwigs – and Japanese beetles!
The Tachinid fly uses a special appendage called an ovipositor to pierce the skin of the Japanese beetle. They then lay their eggs beneath the skin of their unsuspecting victims. Other tachinid fly species may lay their eggs on the exoskeleton (the outer skeleton) of the beetle. Once the larvae hatch, they burrow through the body of the beetle, often leaving their host when the time comes for them to pupate, and killing the beetle in the process.
Tachinid flies have been found to be highly effective for the control of Japanese beetles, as well as other problematic garden bugs (like caterpillars).
There are plenty of birds that eat Japanese beetles. But which of our feathered friends are most likely to reduce your beetle population?
The best-known Japanese beetle eaters are starlings, as they will devour both the adult bugs and their larvae. Plenty of other birds will eat the larvae of the Japanese beetle, including:
- Blue jays
- Eastern Kingbirds
- Purple Martins
Do chickens eat Japanese beetles?
Chickens eat all kinds of bugs, including Japanese beetles! A flock of these Japanese beetle predators in your backyard can help to keep your plants free from attack by bugs but beware; chickens also adore veggies. They can peck their way through lettuce, chard, and spinach, and may also damage tomato and squash plants.
What animals eat Japanese beetles? As it turns out, plenty of animals will dine on these invasive pests.
Mammals such as skunks, raccoons, moles, and hedgehogs are all voracious bug-eaters, and will chomp down any beetles they come across.
Other predators of Japanese beetles
Any predator with a varied diet will attack and eat Japanese beetles. Several spider species, assassin bugs, and predatory stink bugs are also known to prey on the beetles.
How to encourage Japanese beetle predators in your garden
There is a planet of animal, insect, and bird species that prey on Japanese beetles, but how can you use this information?
It is possible to encourage the presence of Japanese beetle predators in your garden by making your backyard wildlife-friendly. This means planting a wide variety of plants, including trees and hedges, which provide much-needed shelter and food sources for critters. You may also consider putting up a few bird boxes, feeders, tables, or baths, which can encourage avian predators into your backyard.
Certain plants, herbs, and flowering plants can attract tachinid flies (an important predator of Japanese beetles!). To attract tachinid flies, you can plant:
- Other flowering plants
- Other herbs
Japanese beetles are a serious pest of over 300 plant species in the United States. This invasive species was accidentally introduced to North America in 1916 and has settled throughout the eastern states since then. They can cause extensive damage to flowering plants, trees, shrubs, turf, fruits, and vegetables, but what can you do to control them?
Luckily, Japanese beetles are delicious for a wide range of mammal, birds, and insect predators. Starlings are known to eat both the adult beetles and their larvae, and many other bird species will feast on the grubs (including chickens). Animals such as skunks, raccoons, and moles will also hoover up large numbers of the bugs, and tachinid flies parasitize the adults.
Encouraging wildlife species into your garden is the best way to reduce your Japanese beetle population. Plant a wide variety of flowering plants and herbs to draw insects in, and consider installing bird boxes to attract avian predators.