Is Your Lawn Safe from Grubs?

Summer is here and this means we get to enjoy the outdoors more! The sun calls our name and out we go to enjoy natures beauty all around us with picnics, barque’s, evening walks, sitting on the lanai, kids games and just plain old-fashioned family outdoor fun. Something we don’t really think about when it comes to summer is insects and the damage they can do during the summer time. The warm, tropical climate across Florida and especially in Southwest Florida makes the presence of lawn pests highly problematic. Common pests in Southwest Florida lawns include grubs. If not controlled in time, grubs can cause serious damage to lawns.

GRUBSWhite grubs are immature scarab beetles. They hatch from eggs laid in the soil, have three larval instars, and also pupate in the soil. The third instar is often the most damaging and may be present in the soil the longest. The adults are rarely turf pests, but some may feed on tree leaves or make mounds in the soil. White grubs may have one or more generations each year in Southwest Florida.

LIFE CYCLES – The most abundant species of masked chafers in Southwest Florida are Cyclocephala lurida and C. parallela. They have 2 generations each year throughout Florida, and the first generation is the most damaging. Adults are tan, about 5/8 inch long, and slightly smaller than May/June beetles. Adults fly from April to June and again in August and September. They are attracted to lights at night, but do not feed. Adults lay their eggs in the top inch or two of soil, often in small clusters. Small grubs hatch from the eggs and feed on grass-roots. Most damage occurs from the first generation by July or August. The raster pattern is indistinct and does not have any rows of short, thick hairs. They pupate in earthen cells.


Grubs are the larval stage of May or June beetles and masked chafers. The white, c-shaped insects have brown heads, three pairs of legs and range in size from ¼ to 2 inches. The insects have hair on their abdomen.


When white grubs feed on grass-roots, the grass gradually thins, yellows, and dies. This makes the grass feel soft and spongy. Scattered, irregular, brown patches of grass appear, which increase in size over time. The root injury reduces the turf’s ability to take up water and nutrients and withstand drought stress. Heavily infested grass pulls up easily.

In addition, white grubs attract moles, raccoons, armadillos, and birds, which can make an already damaged area look worse. However, these animals may be interested in earthworms or other insects besides grubs. Large numbers of dark-colored, parasitic wasps with yellowish to white stripes on their abdomens that hover over the lawn on sunny days in the summer or fall may also be a sign of infestation. Sample the area to confirm that a white grub problem really exists.


Grubs feed on grass-roots and cause grass to slowly thin, yellow and die. Infested lawn areas feel spongy and soft. Damage appears in the form of scattered brown patches that gradually increase in size. The pests also invite secondary predators like birds, armadillos and moles that dig and damage the lawns searching for the grubs.


You can control grubs in lawns with the introduction of insect parasitic nematodes from the Steinernema or Heterorhabditis species. Insecticidal control options include the use of trichlorfon, imidacloprid, thiamethoxam and halofenozide. This is where Lenny’s Pest Control comes in – we’re here to help you reach your goal of a beautiful, healthy, lush Southwest Florida lawn! Our lawn care specialist will take the time to inspect your lawn and identify the current problems.  We always take time to answer all your questions and educate you about what needs to be done for your lawn. Take advantage of our summer special and save today!

St. Augustine Grass & Insects –  Several insect pests cause serious damage to St. Augustine grass lawns. The Southern lawn chinch bug is the most serious pest on St. Augustine grass in Florida where the insect if active most of the year. In other states it ranks among the most serious pests along with SAD, brownpatch and white grub.

The chinch bug damages St. Augustine grass by feeding on the stems at the base of the leaf sheath. Populations of chinch bugs may reach several hundred per square foot with damage usually apparent at 20 to 30 chinch bugs per square foot. Initial injury symptoms from chinch bugs resembles drought stress — stunted, chlorotic spots in open (full sun) areas of the lawn. As feeding continues, irregular areas of dead grass develop in the lawn.

Timely applications of insecticides will control chinch bugs. Two or more treatments are required during the growing season in most areas, and as many as 5 or 6 may be required in some areas of Florida. Floratam St. Augustine grass is resistant to the Southern lawn chinch bug and is widely used in South Texas where the grass is adapted. In Florida severe damage to Floratam has been observed in lawns infested with chinch bugs.

White grub are also a serious pest on St. Augustine grass lawns. The grubs are the larvae of the May beetle or June bug that develop in the summer and fall just below the soil surface. The grubs feed on roots of St. Augustine grass and cause significant losses of turf during some years. Damage usually appears the following year as dead areas of grass that can be easily lifted from the lawn.

Grub control is difficult since the larvae are often quite large when detected and feed below the soil surface. Also, for them to be effective, insecticides must be drenched into the soil where the insects feed. Since some insecticides are tightly bound to the thatch layer of St. Augustine grass, drenching the material into the soil is difficult.

Timely and proper application of insecticides is the only method of controlling white grubs. Since they are only an occasional problem, inspection of the turf in midsummer is required for effective control. Biological control with milky spore disease has not been effective against this species of white grub.

Sod webworms, armyworms and cutworms can also feed on St. Augustine grass leaves and can cause damage when infestations are heavy. Evidence of heavy feeding by these insects includes a skeletonized appearance of leaf blade, silk-like webs visible in early morning (webs cover earthen tunnel in the thatch layer of turf) or defoliation of lawn in irregular patches. All of the leaf-feeding insects can be easily controlled by insecticides or biological worm control. (Bacillus sp.)

Ground pearls, subterranean scale insects that feed on roots of grasses, can also cause damage to St. Augustine grass lawns. The scale insects attach themselves to grass roots and secrete a waxlike shell around their bodies that resembles a pearl. At the immature scale inside the pearl grows larger, the pearl also increases in size. The pearl may reach 1/8 inch in diameter, and can be found attached to grass roots in the top several inches of soil.

Ground pearl damage becomes evident in spring and summer, particularly during dry periods, as small irregular areas of unthrifty or dead grass. Insecticide treatment should be made in May or early June when the insect is in the crawler stage. Consecutive treatments for 2 or more years may be required for effective control.

Lenny’s Pest Control has a team of experts that specialize in Southwest Florida Pest Control inside and outside of your home. We are experienced in tackling the GRUBS and any other insects in your living space. Don’t try to fix it yourself, let the experts handle all of your pest control problems! We proudly service the Lee, Charlotte and Collier Counties.  Call us at 239-945-6543 or visit our website at get a quote today!

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