Fruit IPM Factsheet Fruit IPM Factsheet
Variegated LeafrollerScientific Name-
Platynota flavedana (Clemens)
Family-
Tortricidae
The variegated leafroller was first reported by Riley in Missouri in 1869. It is a common pest of strawberries in the Midwest and a major pest of apples in the Southeast.
Life Stages
Egg: Eggs are elliptical and light green when first laid, but yellowish after two or
three days. The eggs are normally laid in flattened egg masses of 20 to 150 eggs on the
upper leaf surface. They hatch in seven to 10 days. Before hatching, the black head
capsule of the developing embryo is visible through the chorion.
Larva: The newly hatched larva is about 1.2 mm long. The
dorsal body is apple-green, while the ventral surface is a paler and more amber green. The
head capsule is amber to light brown. The mature larva is 13 to 21 mm long.
Pupa: The pupa is brown and about 9 mm long.
Adult: The adult of the species are dimorphic. The forewing of the male is black-brown (almost purple) except for a small part of the base next to the body and the outer portion, which is light colored. The entire forewing of the female is reddish brown except for two darker reddish horizontal bands. The female is usually slightly larger then the male. The wing expanse ranges from 12 to 19 mm.
Host Range
This leafroller has been reported feeding on apples, peaches, roses, cotton, azalea, strawberries, begonia, helianthus and young maples. It is considered a general feeder. It occurs from eastern Massachusetts to southeastern New York, along the east coast to Florida, Louisiana, southeaster Texas and Arkansas to Kansas, Iowa, Illinois, Virginia, West Virginia, Pennsylvania and Michigan.
Injury
or Damage
The variegated leafroller is a serious pest of strawberries. Injury results from the activity of the larvae, which fold and web the leaves together and feed within the protective canopy. This weakens the plants and inhibits the growth of runners. Larvae may also feed on berries.
Peaches can also be injured by larval feeding. On apples, foliage feeding is slight and of little significance. Larval feeding on fruit occurs when a dead leaf is attached to the side of the fruit or when fruits are clustered together. The larva then chews out shallow areas of the fruit. Fruit feeding by large larvae is often quite extensive. These feeding areas are separated and look like small, shallow pecking marks compared with the more continuous feeding damage of the redbanded leafroller. Damage by variegated leafroller larvae is quite similar to that caused by tufted apple bud moth, though tufted apple bud moth shelters are unique with their cut petioles.
Factors Affecting Abundance
Because it is a general feeder, it has many host plants. Plantings of strawberries in the vicinity of orchards can contribute to orchard populations.
Life History
In orchards, the variegated leafroller overwinters as dormant larvae in leaf litter on the apple orchard floor. In April, larvae feed on ground cover and apple root suckers.
Pupation occurs in early May. The pupal stage lasts seven to 10 days. Spring moths begin emerging in early June and are present in orchards until late July. Second-generation adults emerge in late August to early September. Egg masses are laid on the upper sides of apple leaves in June and July and again in September in spherical, rectangular or oblong masses of 20 to 150 eggs.
The incubation period averages about two weeks for the first generation and about nine days for the second. The first generation has five instars, though there may be an occasional sixth. The average time for larval development is about one month. As soon as they hatch, the larvae web and construct feeding shelters on the leaves; later they fold leaves upon which they feed. The larvae will also feed. The larvae will also feed on the fruit.
Like most tortricids, the larvae wiggle violently and spin to the ground when disturbed.
The larval stage lasts about two weeks. The pupal period averages about a week. Fruit is damaged in late summer and early fall by late instar larvae of the second generation. Second-generation larvae continue feeding into October and overwinter in the larval stage.
Monitoring
Use pheromones to monitor brood emergencies. When the larvae in the early and late summer broods begin to feed, examine 30 fruit from each of 10 trees in the orchard. Treatment is recommended if the total number of larvae for the early or late summer broods is five or more, or if there is other evidence of fresh feeding.
Control
Use pheromones to monitor the presence of adults in the orchard. Controls are most effective when directed against the early instars.
