UF/IFAS Okeechobee County Extension Service
458 Highway 98 North
Okeechobee, FL 34972-2578
Phone: (863) 763-6469
E- mail: firstname.lastname@example.org
Article - for release the week of
Article - for release the week of
Dan Culbert - Extension Horticulture Agent
Spots? You may
One of the most impressive creatures found in our Florida Yards is the Ox Beetle. Our office is often asked to identify this one and one-half inch long dark brown beetle with one or three long horns on the front of its body. And usually the next question asked is, does it hurt my plants?
While the majority of insects found in and around the home donít cause significant problems to our yards, this beetle larva can cause damage to the lawn. Turf damage begins as temperatures warm in the spring, and if they are a problem, management should begin now.
Many beetle larvae are found among
grass roots. Beetles
lay eggs on the soil surface in late summer.
low mound of soil with a hole on the end shows where
the female lays her eggs.
As eggs hatch and burrow through the soil, they
feeding on plant roots and grow into one to 3-inch sized
Several species of white grubs damage grass including the May or June beetles (Phyllophaga sp.), masked chafers (Cyclocephala sp.), and the Ox Beetle (Strategus sp.). White grubs are, well, white, but on closer inspection their heads are brown and the rear of the abdomen is dark area. Grubs have three pairs of small legs near the head, and curl up at rest in a C-shaped position.
|May or June beetles (Phyllophaga sp.) Photo: UF||Masked chafer beetle. Photo: UF||
Between one and four years is
required to for grubs complete their life cycle, and in
certain years heavier infestations occur. Adult beetles do
not damage grass but usually feed on flowers and foliage
or ornamental plants upon emergence in the spring.
Young landscape plants or tree seedlings are also chewed up by white grubs. In turf areas, yellowish areas are an indicator that grass is being chewed. In severe cases grass roots are eaten so much that a mat can be rolled back like a carpet. If grass wilts in an area of the turf even though adequate water is available, an infestation of root-feeding grubs should be considered.
|Beetles emerge from the ground in spring to mate and lay eggs. Photo: UF||Turf Damage from White Grubs appears as irregular yellowed areas that turn up dead. Photo: UF/IFAS||This white grub is attacking Seashore Paspalum in Fort Pierce. Photo: Dan Culbert, UF/IFAS|
Grubs damage the grass by feeding on the roots about an inch below the soil surface. Their feeding causes the grass to turn yellow and then brown. The damage may first appear as spots only a few inches in diameter, but these spots will gradually become larger as feeding continues. Heavy infestations completely destroy the roots, and the grass can be rolled back like a carpet.
Moles, skunks and armadillos feed on the grubs. Unfortunately, they may damage the lawns or ornamental plants while searching for these insects. To discourage their rooting activities of these forms of wildlife, best management recommendations call for the control of grubs.
To inspect for grubs, cut three sides of a one-foot piece of sod, two-inches deep with a flat spade under the grass, and lay it back. See if the grass roots are chewed off and sift through the soil looking for these white larvae. Replace that strip of sod, and inspect other areas in the lawn, especially those with yellowing spots. If two or three grubs are found per square foot, use of an approved insecticide is suggested.
While there are wasps known to parasitize grubs, none of these wasps are widely available on a commercial basis. Other grubs are being managed by bacterial-based products, but these are expensive and difficult for most homeowners to apply for grub management.
Other factors can cause off color
areas in lawns, such as chinch bugs, turf diseases,
sprinkler malfunctions, or fertilizer problems.
Good landscape managers must determine what the
cause of the problem before corrective measures are taken.
And if an infested turf area is being converted
into a vegetable garden, avoid planting root-type crops, a
favorite food of grubs.
To help prevent contamination and
reduce the destruction of beneficial insects, spot
treatments can be applied when damage is first noticed and
areas are small. Treat
the off-color areas and the surrounding 10-foot areas.
If damage is widespread, the entire yard should be
treatment, inspect the area two to three different times
twice a week to determine if infestation is under control.
Links to White Grub Pesticide recommendations from University of Florida/IFAS:
|2005 Turfgrass Pest Management Guide: http://turf.ufl.edu/2005PestControlGuide.pdf, go to p.15/74|
Granular insecticides and liquid concentrates are used to manage white grubs. Besides traditional compressed air sprayers, hose-end applicators are popular homeowner equipment for many grub insecticides. Those that use 15 to 20 gallons of water passing through the hose to empty a quart sized jar are appropriate kinds of applicators. Put the amount of insecticide in the jar as directed on the label for 1000 square feet. Fill the remainder of the jar with water. Spray the contents over 1000 square feet. To insure even coverage, spray back and forth across the same area.
When spraying for control of white grubs, the turf should be moist at the time of application. Immediately after spraying the insecticide, product labels will usually require that the turf be irrigated with a half-inch of water. This will soak the insecticide into the soil where the insects are feeding.
Use Insecticides Safely
Insecticides are poisons and should
be handled as such. Read
the manufacturer's label carefully before opening the
container and observe all instructions and precautions.
Wear rubber gloves when handling and applying
not breathe mists or fumes or spill sprays on the skin.
Iíve placed more information on our Okeechobee web page, http://okeechobee.ifas.ufl.edu. If you need additional information on white grubs, please email us at email@example.com or call us at 863-763-6469. Local residents can stop by our office at 458 Hwy 98 North in Okeechobee, and visit our Okeechobee County Master Gardeners from 1 to 5 PM on Tuesday afternoons.
Trade names, where used, are given for the purpose of providing specific information. They do not constitute an endorsement or guarantee of products named, nor does it imply criticism of products not named. The Florida Cooperative Extension Service - Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational information, and other services to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin. Florida Cooperative Extension Service / IFAS / University of Florida. Larry A. Arrington, Dean Last update: 04/04/2006 . This page is maintained by Dan Culbert
Daniel F. White
Press Journal, released
Weissling,T. Of grubs and porch lights. In Garofalo,Joseph, PROSCAPES (newsletter). Miami: Dade Co Extension Service, July 2003. p.5 http://miami-dade.ifas.ufl.edu/programs/commurb/newsletters/Proscapes%20July%202003.pdf
white grub escaping