|
 Correction:
The "Fighting Grubs" article that appeared in the May issue of Lawn & Landscape mistakenly included crabgrass control options rather than grub control options. Some active ingredients that Weed Man finds effective for preventive control of grubs are: halofenozide, imidacloprid, chlorantraniliprole, thiamethoxam and chlothianidin. Some active ingredients that Weed Man finds effective for curative control includes: trichlorfon and carbaryl.
One of the most destructible pest problems that arise during spring and fall are grubs.
According to the U.S. Department of Agriculture, it is estimated that grubs cause more than $200 million in damage a year to lawns.
In order to properly treat grub-infested lawns and ensure they stay healthy, it is crucial that you understand how to identify grubs, their lifespan and the symptoms of grub damage, along with the various treatment options that are available.
Identification. Grubs, which are generally found on the East Coast and in the Midwest, are small, plump white larvae that live below the soil surface and chew on the roots of the grass.
They are the larval stage of a group of beetles, including the European chafer, June beetle, Japanese beetle, Asiatic garden beetle and the oriental beetle.
While grubs are typically cream-colored and have six legs with an amber-colored head, the size of grubs will vary depending on the species and its age.
Lifespan. While the typical lifespan of the beetles is about a year, it is not uncommon to come across grubs that have a lifespan of approximately three years.
Grubs are most destructive late summer, but mating between beetles occurs in late June. As the grub larvae sit about 3 inches from the soil surface, they feed off the roots of the grass.
This process will continue into August as they continue to feed off the grass and grow larger. As summer starts to wind down and frost approaches, the grubs will move down into the soil and hibernate in order to make it through the winter season.
Damage. Because grubs chew on the grass roots, the turf will appear brown. Grub damage may be confused with drought or dead patches of lawn. If the lawn is infested by grubs, you will be able to roll the sod back like a carpet. Additionally, be on the lookout for animals like skunks and raccoons.
If grubs are burrowing themselves underneath the turf, these animals will dig up the lawn in order to feast on them.
It is also important to remember that beetles like to lay their eggs in areas with adequate soil moisture and plenty of sunshine.
Control. The most favorable time of the year to implement grub control treatments is early summer right after the eggs hatch.
The most easily accessible method to controlling grubs is to closely monitor the lawn.
Start observing late summer for off-color spots, especially in areas that have been irrigated. There are curative and preventive products available to help control grubs.
Preventive products should be applied as early as mid-April to the end of May when grub eggs are hatching or are small. The most effective control is products with the active ingredients halofenozide, imidacloprid, chlorantraniliprole, thiamethoxam and chlothianidin.
Curative products should be applied in June or early July when the grubs are active. Effective active ingredients are richlorfon and carbaryl.
If seeking an alternative control, nematodes are multi-celled organism that feed on grubs.
In particular, they are most efficient at eliminating Japanese beetle grubs alone with the European chafer grubs. L&L
The author is chief operating officer at Turf Holdings Inc./Weed Man USA. She can be reached at jlemcke@giemedia.com.
|
