If your lawn has irregular-shaped areas of weakened or dying grass you are in danger of losing large parts of your turf grass. Immediate attention is required to prevent further damage and return your lawn to a beautiful healthy state.
Here Is What You Need To Know About Grubs
In Keller, Texas we often sometimes refer to grubs as grub worms. For our purposes in this information, we simply refer to them as grubs.
White grubs are the larval stage of insects commonly known as May or June beetles (or June bugs). Almost 100 species live in Texas, most of which do not cause significant economic damage to crops or horticultural plantings. A few species, however, commonly damage turf grass and other cultivated plants.
Grub worms injure turf by feeding on roots and other underground plant parts. Damaged areas within lawns lose vigor and turn brown. Severely damaged turf can be lifted by hand or rolled up from the ground like a carpet.
Texas Turf Grasses Most Affected
The most important turf grass infesting white grubs in Texas are the June beetle, Phyllophaga crinita and the southern masked chafer, Cyclocephala lurida.
Warm season grasses like Bermuda grass, Zoysia grass, St. Augustine grass, and Buffalo grass are attacked readily by both types of white grubs, with most lawn damage occurring during summer and fall months.
Once a year, in late spring or summer, adult beetles emerge from the soil to mate. Mated females then return to the soil to lay eggs. After mating, female beetles dig 2 to 5 inches into the soil to lay eggs. Each female can lay up to 30 to 40 eggs. Within about two weeks the eggs hatch into small white grubs that feed on grass roots.
The pupa, or intermediate stage between the larva and the adult, occurs the following spring and is the last immature phase of the insect’s development cycle. Adults subsequently emerge from the pupal stage when environmental conditions are favorable in early- to-late-summer. Most damage from white grubs occurs during midsummer to early fall when the larger larvae are actively feeding.
What Grubs Look Like
White grub larvae are creamy white and C-shaped, with three pairs of legs. After hatching, the white grub passes through three larval life stages, or instars. These instars are similar in
appearance, except for their size.
First- and second-instars each require about three weeks to develop to the next life-stage. The third-instar actively feeds until cool weather arrives. Third-instar larvae are responsible for most turf grass damage due to their large size (1/2 to 1 inch long) and voracious appetites.
Feeding by large numbers of third-instar white grubs can quickly destroy turf grass root systems, preventing efficient uptake of food and water. Damaged turf does not grow vigorously and is extremely susceptible to drying out, especially in hot weather.
Fall Weather Impact
When cool weather arrives, white grubs become dormant until the following spring. During this dormant period white grubs do little or no feeding and cause little damage. Occasionally white grubs will be found in turf grass areas that fail to green up in the spring; however, the damage is primarily the result of feeding that occurred the previous fall. Spring and winter treatments for white grubs with one-year life cycles generally are ineffective in preventing turf damage.
When to Treat For Grubs
The best time to inspect for grubs and apply insecticides occurs approximately five to six weeks after the heaviest June beetle flights. Peak June beetle flights occur at different times of the year in different parts of the state. So in Keller, Texas the best times to treat grubs is between late July and August. Within a given locale like Keller, flight periods may vary as much as two months from year to year, due to variations in rainfall.
TurnKey Lawn Service is always monitoring grubworm conditions and we can give you accurate information each season. Keep in mind that because we service a large number of Keller lawns, with various turf grasses, we can share with you trends as we see them and often recommend preventative treatment before your lawn becomes severely damaged by grub infestation. Here’s why.
Proper timing of insecticide treatments is one of the most critical elements for successful suppression of white grubs. Both chemical and biological control measures are most effective when applied against smaller (less than 1/2 inch long) larvae, and less effective against eggs, larger larvae, and pupae.
The residual effectiveness of most insecticides is greatly reduced one to two weeks after application; thus, insecticides applied too early may not remain effective in the soil through the egg hatch period. Insecticides applied after the optimal treatment period is often less effective because white grubs have become large and difficult to kill.
Call Larry at TurnKey Lawn Service – Call 817/271-6125 – or send an email - for a free consultation and inspection of your yard.