Invasion Continues: Japanese Beetles Lay Eggs for Next Wave

invasion continues japanese beetles lay eggs for next wave.jpg Science

Millions of metallic green invaders have taken over Ohio this summer, wreaking havoc on plants and landscapes. These invaders, known as Japanese Beetles

Japanese Beetles: A Menace to Ohio’s Foliage

Millions of metallic green invaders with brown wing covers have been wreaking havoc on Ohio’s foliage this summer. Known as Japanese Beetles, these pests feed on over 300 different species of plants, munching on anything in their path. They are ruthless eaters, consuming only the leaf tissue and leaving behind withered and skeleton-like plant veins. As larvae, they even devour entire root systems, turning lawns and flowerbeds into dried, brown patches.

A Foreign Invasion

The battle against Japanese Beetles in North America has been ongoing for 107 years. These beetles were brought to the United States by gardeners from Japan during the World’s Fair in 1916. It is suspected that the beetles’ larvae, known as Popillia japonica, were hidden in the soil around the plants they brought. The beetles quickly established themselves, with the first population being discovered in a nursery in New Jersey. By 1972, they had heavily infested 22 states east of the Mississippi River.

Life Cycle and Impact

In August, female Japanese Beetles lay up to 60 eggs, about 2 to 4 inches deep in the soil. The eggs develop into grubs, which feed on roots and organic material throughout the year. By winter, the grubs burrow about eight inches deep to survive until spring. In mid-April, they return to the surface, pupate, and emerge as adults in June. The adults are active for about two months, laying their eggs in August to continue the cycle. The grubs cause brown patches in lawns, while the adults strip plants of their leaves, leading to their demise.

Control Methods and Challenges

Controlling Japanese Beetle populations can be expensive. The federal government’s primary objective is to limit their spread out west. Bag lures, using pheromones to attract beetles into a trap, are commonly used east of the Mississippi. However, this method can inadvertently draw in more beetles and lead to a larger population of grubs the following autumn. Commercial growers often resort to chemicals, which can harm beneficial members of the ecosystem. One promising control method is the introduction of the spring Tiphia, a parasitic wasp that attacks the beetles in their grub stage. However, this method is still being studied and implemented.

Taking Matters Into Your Own Hands

While waiting for effective control methods, individuals can take action against Japanese Beetles. Dr. Cindy Perkovich, an entomologist at Ashland University, suggests using a bucket filled with soapy water to drown the beetles. By getting rid of the females before they lay their eggs, the number of grubs next year can be reduced. This simple method can help protect gardens and plants from these destructive invaders.

In conclusion, Japanese Beetles pose a significant threat to Ohio’s foliage. Their voracious appetite and ability to reproduce quickly make them difficult to control. While various methods are being employed to combat these pests, individuals can also play a role in reducing their numbers. By staying vigilant and taking action, we can help protect our gardens and preserve the beauty of Ohio’s green spaces.


  • Japanese Beetles are invasive pests that feed on a wide range of plants, causing significant damage to foliage.
  • They were brought to the United States from Japan during the World’s Fair in 1916 and quickly established themselves.
  • The life cycle of Japanese Beetles involves laying eggs in August, developing into grubs that feed on roots, and emerging as adults in June.
  • Controlling Japanese Beetle populations can be expensive, and chemical methods may harm beneficial organisms.
  • Individuals can use simple methods like drowning beetles in soapy water to help reduce their numbers and protect plants.
Crive - News that matters