Billbugs are a particular problem of Kentucky bluegrass lawns. Members of the weevil family, the adults have long snouts that end in a set of mandibles. Adult billbugs are 1/4 to 1/2 inch long and brown or gray. The larvae do the most damage to the stems of grass plants, however adults will also cause some stem and leaf blade damage. The larvae are small legless white grub-like creatures with a yellow-brown head. They look much like a grain of puffed rice. They feed on stem tissue causing infested shoots to turn brown and die. Billbugs over-winter as adults and emerge in April or May. In late May, females lay eggs in lawn grass stems above the crown in May and June. In June, larvae move into the soil and feed on roots and rhizomes. They remain near the soil surface feeding near the thatch layer when it’s moist. As soils dry, they go deeper. In July, adults appear. Proper identification and treatment are needed when dealing with these insects, in order to maintain effective control.
Chinch Bugs are not as common as some other turf-feeding insects such as grubs or sod webworms, but left unidentified and untreated they can devastate a lawn very quickly. The pests are so small and inconspicuous that they can destroy a lawn right beneath your eyes without being noticed. Chinch bugs cluster in lawns down among grass blades near the crowns of the grass plants and suck juices from their tissues. Their feeding causes grass to appear yellowish and sometimes stains the grass red. These bugs thrive in hot, dry weather, becoming active when temperatures are in the high 70s, and causing most of their damage from August to September, when Northern grasses are stressed from the summer heat. Lower than average temperatures plus moisture retards chinch bug activity. Topical insecticides, combined with regular monitoring are needed to properly control them.
Grubs are perhaps the most hated pest insect in the country. “Grub” is a catch-all term for the larval, or worm, stage of many kinds of beetles. May beetles (also called June bugs), Japanese beetles, masked chafers, billbugs, etc are all grubs in the soil prior to emerging as beetles during the growing season. Grubs are plump whitish colored worms that grow 3/4 to 1-1/2 inches long. They have 3 pairs of legs and tan heads with large, brown-black mouth parts. They rest in a characteristic C-shaped curl just under the soil surface in planted areas or turf, where they feed on roots of ornamental plants and lawn grasses. Grubs are a subsurface feeding insect and therefore must be treated with the correct insecticide in order to establish control. They are often blamed for many lawn problems in error. Grubs emerge from underground and feed only during certain periods of the year, but many blame any browning in their lawn on grubs regardless of the time of year. That is why a correct diagnosis and then sub sequential proper treatment plan should be developed, rather than making incorrect assumptions. The best plan is prevention. Since grubs primarily feed during the fall months, a preventative can be applied late in summer to ensure effective control the entire fall.