Will Hudson

Fall Armyworms

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Source(s): Will Hudson, Extension Entomologist, The University of Georgia College of Agricultural and Environmental Sciences.

Georgia lawns are under attack. Fall armyworms are chewing their way through turf, leaving destruction in their wake.

Fall armyworms are the larval or caterpillar stage of a nondescript, small gray moth which overwinters in Florida and the tropics. Each year, storms bring the adult moths north. The females lay masses of up to 700 eggs on just about everything. The eggs are cream-colored at first, but turn darker as the tiny caterpillars get ready to hatch.

The first battalion of females lays eggs in south Georgia. Succeeding generations march up the state, traveling on weather fronts and storms. Fall armyworms can’t overwinter in north Georgia. They may survive a mild winter in Florida and extreme south Georgia. The caterpillars hatch from eggs in two to four days, depending on the temperature. Eggs develop to fully grown larvae in two to four weeks. The larvae burrow into the soil and form pupae. Moths emerge in about 14 days.

The first sign that enemy armyworms are near might be large clusters of birds on your lawn. Look closer at the grass, and you may see several caterpillars munching on the turf blades. Although birds eat armyworm caterpillars, they are no match for hundreds of them on one lawn. When hundreds or thousands of armyworms are present, however, homeowners may opt to kill worms with an insecticide .

Young armyworms are one-quarter to three-quarters of an inch long. Mature ones are one and a half inches long. They are dark, with several light stripes down the length of the body. The head or “face” has an inverted Y on it. If you suspect your turf is being infiltrated but can’t find the caterpillars on the grass, use a soap flush to bring them to the surface.

Armyworms rarely kill grass, but some lawns may be severely weakened. Feeding damage, coupled with damage from the recent drought, may justify applying insecticides. In turf or pastures, finding five caterpillars per square foot is a signal to start treating for fall armyworms. Carbaryl (Sevin), pyrethroids and other recommended insecticides are effective caterpillar killers.

Products containing Bt (Bacillus thuringiensis) are effective only on little (a half-inch or smaller) worms. Irrigate before treating, to move the caterpillars out of the thatch. Treat in late afternoon, when the caterpillars are likely to begin feeding. If possible, mow before you treat, and then don’t mow for three days after the treatment.

For information on identifying armyworms, contact your local UGA Cooperative Extension office. See the Georgia Pest Management Handbook for more information on controlling fall armyworms.

Resource(s): Insect Pests of Ornamentals

Center Publication Number: 119

Lovebugs

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Source(s): Will G. Hudson, Extension Entomologist, The University of Georgia

Lovebugs are small black flies with red thoraxes. They are members of the family Bibionidae. Several species of this family are native to the southeast, but lovebugs, Plecia nearctica, are relatively recent invaders from the west.

Southern Louisiana experienced flights of lovebugs during the 1920’s. First reports of their presence in Florida were made in 1947 from Escambia County. Since that time, flights have progressively moved southward. In 1974, specimens were collected in the Homestead area of south Florida. Lovebugs also have moved northward and infest parts of all states bordering the Gulf of Mexico, as well as Georgia and South Carolina.lovebug

Two flights of lovebugs occur each year. The spring flight occurs during late April and May, with a second flight during late August and September. Flights extend over a period of 4 to 5 weeks but individual adults live only 2 – 3 days. Mating takes place almost immediately after emergence.

Female lovebugs lay from 100 to 350 eggs. Larvae (immature stages) feed on decaying plant material, particularly in damp areas. They perform a beneficial function by helping recycle organic matter. After larvae mature, they pupate at the soil surface.

Lovebugs do not sting or bite. They feed on the nectar of various flowers. Adult flights are restricted to daylight hours (generally beginning around 10 AM) and temperatures above 68EF. The adults tend to congregate in open, sunny areas and are attracted to some components of automobile exhaust. At night, lovebugs rest on low-growing vegetation.

Lovebugs are a considerable nuisance to motorists. They congregate along highways and splatter on the windshields and grills of trucks and automobiles. Vision can be obscured, and the bugs can clog radiator fins causing vehicles to overheat. A screen placed in front of the grill will keep the radiator fins from clogging, and will protect the front of the car. Splattered bugs should be washed off as soon as possible. Soaking for several minutes with water makes the mess easier to remove. When the remains are left on a car for several days, the finish may be permanently damaged.

A number of insecticides have been evaluated for effectiveness in controlling lovebug larvae and adults. Most of the insecticides were effective in controlling the adults, and several controlled the immature stages. However, insecticidal control of the lovebug is impractical because infestations occur over such a vast area and adults are so mobile that retreatment would be required every few hours to keep a roadway clear. Most commonly available household insecticides will control adults in confined areas such as entryways and porches. Your county Extension Agent can help with the choice of materials for this purpose.

Lovebugs are not without enemies in nature. Larvae are found in extremely high numbers in pastures and other grassy areas, and make attractive prey for certain bird predators including robins and quail. Laboratory studies using invertebrate predators found in lovebug-infested pastures indicated they were voracious predators also. These included earwigs, beetle larvae and a centipede.

Lovebug populations may vary considerably from year to year, and some years are much worse than others. The reasons for these fluctuations are not known.

Center Publication Number: 197

Two-Lined Spittlebug

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Source(s): Will Hudson, Extension Entomologist, The University of Georgia College of Agricultural and Environmental Sciences.

The two-lined spittlebug is an increasingly common pest of Georgia turf grasses. It will feed on all turfgrasses, but it hits centipede turf especially hard.

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Two-lined spittlebug adult Photo: NC State

 

Both adults and nymphs feed on the plants by inserting their needle-like beaks into the stem and sucking out the juices. This causes the grass to yellow, wither and die if it goes unchecked.

The symptoms are similar to the damage caused by chinch bugs. But spittlebug adults are much more mobile. The damage tends to be spread out, rather than concentrated.

Spittlebugs overwinter as eggs in plant stems, under leaf sheaths or in plant debris.

Nymphs hatch in the spring and begin feeding. They exude a white, frothy mass around them that resembles spittle. It serves to protect the nymphs from drying out and from natural enemies.

The nymphs feed for about a month before becoming adults. Adults live for about three weeks and lay eggs for the last two weeks of that time. The eggs take two weeks to hatch in the summer. Two generations hatch each year.

Adult two-lined spittlebugs are about a quarter-inch long and black to dark brown. They have two bright, red or orange lines across their wings. Nymphs resemble small, wingless adults. They’re white to yellowish orange with red eyes and a brown head.

Early damage symptoms will look like yellow spots of dead or dying grass. With heavy infestations, these spots may overlap to form large areas of dead turf.

The nymphs are easily detected. Just look on the grass stems near the soil surface for their distinctive spittle masses. Adults fly readily when disturbed and can be flushed from the grass by walking through affected areas.

It’s been reported that spittlebug adults can damage a variety of ornamental plants, too, particularly during late summer and fall, when populations are at their highest levels. The ornamental plants they prefer include hollies, asters and morning glory.

Spittlebug infestations can be controlled with several commonly available turf insecticides. Use plenty of water to apply the insecticide. This volume is easily achieved with a hose-end sprayer, but not with a hydraulic sprayer pulled behind a lawn tractor.

Contact your county University of Georgia Extension Service for recommendations.

Take steps to reduce the buildup of thatch. Nymphs need high humidity to survive. Turf with excessive thatch is much more likely to provide them the conditions they need.

Following good turf management practices, too, can make infestations or reinfestations less likely.

Resource(s):

Insect Pests of Ornamental Plants

Center Publication Number: 94