Monitor for omnivorous leafroller, western grapeleaf skeletonizer, grape
leaffolder, and orange tortrix (in coastal areas) from bloom through veraison.
Also look for natural enemies of caterpillars.
Use the photos below to identify caterpillars
and their damage. Names link to more information on identification and
management.
Click on photos to enlarge
| Caterpillar |
Damage |
Omnivorous leafroller
Identification
tip: Larvae have a black or brown head capsule. Mature larvae
are cream to brownish green with whitish, slightly convex tubercles
on the top of the abdomen.
|
Identification tip:
Rotting and raisining (drying up) of Thompson seedless grapes following
chewing damage by omnivorous leafroller larvae.
|
Orange tortrix
Identification tip:
The larva is straw colored
with a brown head and prothoracic shield.
|
Identification tip: Berries and stems damaged by orange tortrix
have dry-calloused surfaces. |
Grape leaffolder
Identification tip:
Mature larvae are translucent-greenish with small black spots located
above the second pair of legs which distinguish later larvae from
omnivorous leafroller. |
Identification tip: Grape leaffolder larvae curl leaves and
tie them together with silk. |
Western grapeleaf skeletonizer
Identification tip: Feeding by larvae of western grapeleaf
skeletonizer leaves the surface of foliage pale and scraped.
The fourth-
and fifth-instars are yellow with two purple and several blackish
bands.
|
Identification tip: Whitish spots on a grape leaf caused by
feeding of first-instar larvae. |
Continued
feeding by western grapeleaf skeletonizer leaves the surface of
foliage pale and scraped.
|
