Periodical cicadas

Periodical cicadas (Magicicada spp.) are large, stout insects with black bodies, red eyes, and orange-veined clear wings that emerge en masse on 13- or 17-year cycles. In turf they are recognized not by foliar feeding but by their emergence signs: numerous pencil-sized (about 1/2 inch) exit holes dotting the lawn and, in the weeks before emergence, finger-height mud 'chimneys' or turrets built over the holes.

Scattered to dense exit holes about 1/2 inch wide pockmarking the turf, sometimes preceded by short mud chimneys over the holes; the surface looks aerated or disturbed but the grass itself is not fed upon and the lawn is not permanently harmed, with holes filling in over time.

Nymphs live underground for 13 or 17 years feeding on sap from tree and woody-plant roots at depths from a few inches to about two feet; turfgrass roots are not the host. After their long development, mature nymphs tunnel to the surface in late spring, emerge synchronously, molt to winged adults to mate and lay eggs in tree twigs, and die within a few weeks. Newly hatched nymphs drop and burrow back into the soil to begin the next multi-year cycle.

Impact on turf is brief and localized to the synchronized emergence of a given brood in a single late-spring season once every 13 or 17 years; heaviest emergence holes occur near mature trees whose roots the nymphs fed on. The disturbance is cosmetic and self-limiting.