Leaffolders are moths that are black with with white spots and sometimes whites stripes depending on the species. Their larvae do the most damage and are very small caterpillars, clear and are pale green because of the leaves they eat.
Leaf Folder Adult moth-photo Cropnet (left), Leaf Folder Larvae-photo Jack Kelly Clark-University of California (right)
There are several different types of leaffolder each eating only one type of plant. Pupae are long bronze to brown coloured and the eggs are clear.
Egg on grape plant (left), Pupae (right)-photos Jack Kelly Clark-University of California (right)
Habitat and Lifecycle
These are found everywhere in North America. They overwinter as pupae in the soil, emerge in spring and lay their eggs on host plants. After hatching the larvae feed on the leaves and roll themselves in edges of them and continue to feed. If disturbed they will drop to the ground on a silken thread. Once the larvae has completed feeding they pupate in the protection of the folded leaf. They can have as many as 3 cycles per year.
Diet and Damage
They attack lilacs, grapes, rice ond other farm crops. They eat the leaves and also damage the leaves of plants by folding them over (not to be confused with leafrollers). Plants will defoliate and eventually die.
1) Hand Pick
If you have had leaffolder damage in the past dig around the soil in the fall and pick out the pupae. Destroy the adult moths when you see them. If you see rolled leaves pinch them off and drop them in hot soapy water. Eggs can be removed with a moistened cotton swab or regular household alcohol.
An early spray of Bt in the first cycle of larvae will help control them and ensure no second or third generation.
3) Beneficial Inscects
Parsitic flies, parasitic wasps, lacewings, small groundbeetles (they are red with a black stripe) and crab spiders help control the larvae population. Birds will eat adult moths.