Grubs
Grubs (larvae of scarab beetles) are sporadic problems of turfgrass in Florida, but often causes damage beachside and along intercoastal waterway areas. At least five common types occur in Florida.
Grubs feed on the roots of all turfgrass species. They occur at or just below the soil-thatch layer. Mild damage may make the turf look yellowish, which could be misdiagnosed as a nutrient deficiency or disease. Severe damage results in large areas of dead turf because of lack of roots. Damage can be masked if the turf is frequently irrigated, but if drought or another stress affects the infested turf, the grass will quickly die. Damage from mature grubs is most pronounced during late summer and early fall.
Identification: The larvae are fat-looking grubs usually lying curled up. They are whitish in color with dark areas at the rear, three pairs of legs, and a tan to reddish-brown head. The adults are beetles. Watch for adult scarab beetles flying at night near lights. Grub damage starts at the roots. Look for areas of yellowing grass. Lawns infected by grubs will often feel spongy under foot and badly infested areas, the sod can be peeled away like a carpet or newly laid sod since the roots are not holding the turf in place. Some grubs in an area is not uncommon (2-3 per sq. ft.) but an infestation will cause serious damage.
Date: November 12, 2009
Categories: Turf Damaging Insects