eight spotted forester
Beginner
Scientific Name
Alypia octomaculata
Identification
Larvae
- Yellow, black and white stripes and black spots
- 3.3 cm long when mature
Adults
- Black with white, orange and yellow markings
- Two yellow spots on each forewing, two white spots on each hindwing
- Fly during the day
Damage
- Entire leaves or the interveinal areas of leaves are chewed and webbing may be present on leaves
Injury Often Confused With
Grape Plume Moth: 2 cm green larva with white hairs; Terminal leaves of shoots are webbed together and chewing damage is evident.
Japanese beetle: adults are easily seen feeding and mating on injured leaves; smaller veins are left behind after feeding, giving leaves a lacy appearance.
Period of Activity
Spring to early fall.
Scouting Notes
When scouting for grape berry moth larvae along borders of vineyards, make note of any eight-spotted forester adults or shoot injury from larvae on vines or alternate hosts.
Threshold
None – This is a pest of low impact with rare exceptions.
Advanced
Scientific Name
Alypia octomaculata
Identification
Larvae
- Yellow, black and white stripes and black spots
- 3.3 cm long when mature
Adults
- Black with white, orange and yellow markings
- Two yellow spots on each forewing, two white spots on each hindwing
- Fly during the day
Damage
- Entire leaves or the interveinal areas of leaves are chewed and webbing may be present on leaves
Injury Often Confused With
Grape Plume Moth: 2 cm green larva with white hairs; Terminal leaves of shoots are webbed together and chewing damage is evident.
Japanese beetle: adults are easily seen feeding and mating on injured leaves; smaller veins are left behind after feeding, giving leaves a lacy appearance.
Biology
Adult moths emerge late spring and mate. Eggs are laid on grape shoots and leaves shortly afterward. Larvae hatch and start to eat the foliage around bloom and continue to feed, completing development by early summer. The mature larvae drop to the ground and pupate in tunnels they construct just beneath the soil surface. The next generation of moths emerge and lay eggs again in late summer. There may be two generations, or only a partial second generation, each year. Virginia creeper and wild grape are alternate hosts. Damage is most severe along the perimeters of vineyards and in rows near bushes, woods or weedy areas.
Period of Activity
Spring to early fall.
Scouting Notes
When scouting for grape berry moth larvae along borders of vineyards, make note of any eight-spotted forester adults or shoot injury from larvae on vines or alternate hosts.
Threshold
None – This is a pest of low impact with rare exceptions.
Management Notes
Although commercial vineyards are not usually damaged severely, small areas within a vineyard may have concentrated infestations and defoliation. Insecticides applied for grape berry moth or leafhoppers should control eight-spotted forester as well.