White Grubs

White grubs is a general name for the larval stage of beetles in the family Scarabaeidae, order Coleoptera, that feed on the roots of turf. All species of scarab beetles have larvae that are C-shaped and vary in size depending on the species and larval age (instar). Heavy white grub infestations can destroy grass roots, causing the affected area to become spongy, which allows the sod to be rolled back like a piece of carpet. Light infestations do little damage, especially if lawns are healthy. Species of concern in Maine include Japanese beetle (Popillia japonica), European chafer (Rhizotrogus majalis), May or June beetle, also called Junebug (Phyllophaga spp.), Oriental beetle (Exomala orientalis), rose chafer (Macrodactylus subspinosus) and Asiatic garden beetle (Maladera castanea).

It is important to identify the type of grub in your lawn before treating. It is usually necessary to consult an expect for grub identification. Adults are pictured to help with beetle identification. Keep in mind, however, that adults do not always stay in the same area as the larvae.

See also Japanese Beetles


damage to lawn by Japanese beetle grubs
Early indications of grub infestation are irregular patches of dry grass, flocking birds, or areas of turf being torn up by raccoons, possums and skunks looking for a tasty treat.

grass pulled back to show grubs
If grubs have been eating the root system, patches of turf will come up easily from the soil surface, like pulling up a corner of carpeting, and the soil will be full of grubs.

larvae of Japanese beetle, European chafer and June beetle
It is important to identify the type of grub in your lawn. Above, left to right: Japanese beetle, European chafer and June beetle larvae.

Japanese Beetles

Japanese beetle larva
Japanese beetle larvae are typical white grubs that are C-shaped when disturbed. First instar larvae are about 1/16 inch long while the mature third instars are about 1-1/4 inch long.

Japanese beetles and leaf damage
Adult Japanese beetles are 7/16-inch long metallic green beetles with copper-brown wing covers. A row of white tufts (spots) of hair project from under the wing covers on each side of the body.

Japanese beetle adult withwinsome fly eggs
Effective biocontrol of Japanese beetles includes winsome fly Istocheta (=Hyperecteina) aldrichi. Adult beetles with eggs on the pronotum, like the one pictured, should not be destroyed.

European Chafers

European chafer grub
European chafer larvae are typical C-shaped white grubs, reaching a maximum size of 1/4 inch wide and 1 inch long.

European chafer adult
European chafer adults are 1/2 inch long. Males and females are a uniform tan or light brown color.

June Beetles

June beetle larvae
June beetle grubs are whitish with brown heads and range from 1/2 to 1 inch in length. These are the largest grubs found in turf.

adult June beetle
All species of Phyllophaga are called May or June beetles. Adults are about 1 inch long and a chestnut brown color and fly to lights in the early summer.

Oriental Beetles

Oriental beetle grub
Oriental beetle grubs cause considerable damage to turf grasses and nursery plants. They eat and destroy the roots of the grass and are found in nursery stock, strawberry beds and some outside potted plants.

adult Oriental beetle
Oriental beetle adults are about 7/16 inch. They vary in color from light brown to black, often with darker mottling on the wing covers.

Oriental beetles in three color variations
Three color variations of the adult Oriental beetle.

Rose Chafers

rose chafer larvae
Rose chafer larvae have a brown head and conspicuous legs. Fully grown, a rose chafer larva is about 3/4-inch long. The larvae feed on the roots of grasses and non-crop plants. They do not cause damage to home lawns or landscape plants.

rose chafer adult
Rose chafers are scarab beetles approximately 3/8 inch long, slender, and light tan in color. They contain a toxin that can be deadly to birds, including chickens, and small animals.

rose chafer adults on skeletonized leaf
Rose chafers are generally found in areas with sandy soil. Adults feed on rose flowers and foliage, skeletonizing leaves.

Asiatic Garden Beetles

Asiatic garden beetle larvae
Asiatic garden beetle larvae has a brown head capsule and six legs. It has three instars.

Asiatic garden beetle adult
Asiatic garden beetles are less than one-half inch long. They are cinnamon in color and have an iridescent sheen in the sunlight. They are attracted to porch lights on summer nights and feed at night, chewing irregular holes in many different plants. During the day, they rest in the soil.

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Control Information

In many instances, organisms that we deem “pests” may not be pests (some may be beneficial), and other organisms may only be pests in certain instances and control may not always be warranted. In most cases, rats are considered a serious health concern and are considered pests.


Best Management Practices

Milky Spore Disease: A Biological Control for Japanese Beetles

Dig Deeper - Scientific Studies

  • Japanese Beetle (Coleoptera: Scarabaeidae) Invasion of North America: History, Ecology, and Management

    Summary: The Japanese beetle, Popillia japonica Newman, was accidentally introduced to the United States from Asia in the early 1900s. First detected in a New Jersey nursery, it is currently established in 28 states in the United States and has been detected in 13 additional states, 3 Canadian provinces, and at least 3 European nations. Adult beetles feed on over 300 host plant species, including many agricultural commodities such as fruits, field crops, and ornamentals, often causing severe economic damage. Authors discuss invasion history, ecology, biology, and management options for this invasive pest species in North America

Think First, Spray Last - Options for Hired Control

In Maine, the Board of Pesticides Control licenses pesticide applicators in several categories. Grub control falls under category 3B (Turf Pest Control). To find a licensed applicator in your area, and search for category 3B and your county.

[Photos, left to right: M.G. Klein, USDA Agricultural Research Service, Bugwood.org; unknown; (three grubs) David Cappaert, Michigan State University, Bugwood.org; (Japanese beetle larvae) Jim Baker, North Carolina State University, Bugwood.org; (Japanese beetle adult) David Cappaert, Michigan State University, Bugwood.org; (winsome fly) unknown; (European chafer larvae) unknown; (European chafer adult) unknown; (June beetle larvae) Steven Katovich, USDA Forest Service, Bugwood.org; (June beetle adult) Steven Katovich, USDA Forest Service, Bugwood.org; (Oriental beetle larvae) unknown; (Oriental beetle adult) Mike Reding & Betsy Anderson, USDA Agricultural Research Service, Bugwood.org; (Oriental beetle adults); Ohio State University photo, Dave Shetlar; (rose chafer larvae) unknown; (rose chafer adult); Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org; (rose chafer adults on leaf) University of Wisconsin Entomology; (Asiatic garden beetle larvae) MSU IPM Resources; (Asiatic garden beetle adult) Mike Reding & Betsy Anderson, USDA Agricultural Research Service, Bugwood.org]