Chemicals That Kill Grubs

Preventative Chemicals

• Preventative chemicals help control grubs before the eggs start to hatch. These chemicals are recommended for use in areas where grubs are a frequent problem. Preventative chemicals have an extended residual activity in soil and usually do not require reapplication. The University of Florida Extension recommends thiamethoxam, imidacloprid, halofenozide, chlorantraniliprole or clothianidin as preventative chemicals for killing grubs.

Application Suggestions

• The best time to apply preventative chemicals is a month before the expected egg hatching time until the grubs are very young. Recommended application is between June 15 and July 15. Water in all chemicals with at least ½ inch of water. Preventative chemicals for controlling grubs are more environmentally friendly than curative chemicals. It is best to read labels regarding application timings prior to applying chemicals.

Curative Chemicals

• As the name suggests, curative chemicals are used for grub control after the presence of pests has been confirmed in lawns. Recommended curative chemicals for killing grubs includes trichlorfon. As opposed to the preventative insecticides, curative products have very short residual effect in soil and chemicals have to be reapplied for best efficacy.

Application Suggestions

• Apply curative chemicals during the summer when the grubs are very young and are still feeding near the soil surface. Once the pests dig deeper into the soil, they are hard to reach with pesticides. The best time for application is anywhere between the middle of August to the middle of September. Curative applications made during spring are less effective than those made in fall since the grubs are larger in size during spring and harder to control. Spring applications will also fail to protect against an infestation from adult egg-laying beetles in fall.