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How to identify it
- Adults are very dark brown, almost black, with a silvery or bluish sheen and a wingspan of about 4/5 inch to nearly 1 1/4 inches. Each forewing has two white spots.[2][1][3]
- On the hind wings, males have a single white bar or spot and females have two white spots. Two white stripes cross the abdomen.[2][1][3]
- Male antennae look thickened and notched near the middle; female antennae are plain and threadlike.[2]
- Caterpillars are glossy and translucent, looking yellow-green to green from the leaf tissue showing through, with a light brown head and fine scattered hairs. They grow to about 3/4 inch (2 cm), and later-stage larvae have small black spots above the second pair of legs.[2][1][3]
- Disturbed larvae wriggle hard and drop to the ground without spinning a silk thread.[2][3]
- Eggs are tiny, about 1/32 inch, flat, iridescent and elliptical, laid one at a time on the leaves, often in the angle between a vein and the leaf surface.[2][1][3]
Look-alikes
| Look-alike | How to tell them apart |
|---|---|
| Omnivorous leafroller | Another caterpillar pest of grapes. UC IPM separates grape leaffolder larvae by the small black spots above the second pair of legs on later-stage larvae.[3] |
| Other Desmia moths | In Florida, other Desmia species and similar moths have more linear white wing spots or a clearly different number of spots.[2] |
Where it lives
Common and widely distributed in the United States. UF/IFAS reports it from Florida and California, and Virginia Tech has seen it commonly in some Virginia vineyards.[2][1]
Biology and life cycle
It spends the winter as a pupa inside folded leaves that have dropped to the ground.[1][2][3]
Moths emerge in spring shortly after grape leaves appear, in April or May in California and in late May or June in Virginia, and lay their eggs on the leaves.[2][3][1]
Young larvae feed in groups between leaves webbed together for about two weeks. Each then rolls or folds a leaf edge with silk strands that contract and pull the leaf together, and feeds from inside, making at least two rolls before it is grown. Larvae fold the thicker leaves of bunch grapes and roll the thinner leaves of muscadines and other thin-leaved varieties.[3][2][1]
Larvae stay inside their rolls except when moving to a new spot at night, and the moths are most active from midnight into the early morning.[2]
To pupate, a mature larva cuts a small flap of leaf on three sides and folds it over into an envelope.[2][3]
California has three generations a year (about April to May, mid-June to mid-July, and August). In Virginia a second generation appears in August and September, and in the southern United States a third brood leads into the overwintering pupae.[3][1][2]
First-brood larvae are few compared with the second brood, and moths of later broods lay most of their eggs on leaves already rolled by earlier larvae. In Fresno, California, egg to moth took 6 1/2 to 7 1/2 weeks for the first brood and 4 to 5 weeks for the second.[2]
Damage and signs
- Folded leaves show their pale undersides, so a vine with many larvae looks patchy even from a distance. Inside the fold the larva skeletonizes the leaf.[2]
- Infestations are often patchy within a vineyard and usually show up first along the borders. The second generation does more damage than the first.[1]
- Heavy third-generation feeding can defoliate vines completely, leading to sunburned berries, soft fruit and larvae feeding directly on the berries. Losing too many leaves can also drain the vine's reserves enough to shrink the next crop.[3][2]
- Vines tolerate a fair amount of leaf loss: UC IPM puts it at about 20 percent one month after fruit set in the San Joaquin Valley, and more later in the season. In Florida the worst damage has come in September and October, after growers stopped spraying for the season.[3][2]
- Varieties with thinner, tender, hairy leaves are attacked more. Wild and cultivated grapes are the main hosts, and redbud, Virginia creeper and Oenothera have been reported as occasional hosts.[2]
Health risk
A grape pest. Virginia Tech, UF/IFAS and UC IPM describe damage to vines only and mention no risk to people or pets.[1][2][3]
Control
Prevention
Watch for young larvae feeding in groups between webbed leaves, and once rolls start appearing, check every 2 to 3 days for a jump in numbers. UC IPM rarely finds the first generation worth treating and judges each later brood on its own.[3]
Sanitation
The pupae spend the winter in fallen leaves, so rake up and destroy grape leaves after they drop.[2][1]
Traps and physical control
In a home planting, go over the vines when folded or rolled leaves appear and crush the larvae by hand. UF/IFAS reports good results this way for gardeners who prefer not to use insecticides.[2]
Biological control
Parasites play a major part in keeping grape leaffolder below damaging levels. The wasp Bracon cushmani often holds second- and third-generation numbers below economic levels, other wasps and at least two kinds of flies attack the larvae, and lacewings and spiders prey on them. Unroll a few leaves to check for parasitism before deciding to treat.[3][2]
Pesticides
If treatment is needed, apply it as soon as a few rolls appear in that generation, since small larvae are easier to kill. Bacillus thuringiensis and an organically acceptable spinosad formulation are options for organic plantings, and UF/IFAS reports that Bt gave control comparable to carbaryl in California and Florida tests. Check current state recommendations before applying any insecticide.[3][2]
Common questions
- What is rolling up the leaves on my grapevine?
- Grape leaffolder injury is distinctive: leaves folded or rolled and held with silk, pale undersides showing, and a translucent green caterpillar inside. Omnivorous leafroller larvae can look similar, but later-stage leaffolder larvae have small black spots above the second pair of legs.[2][3]
- Do I need to spray grape leaffolders?
- Often not. Parasites keep them in check much of the time and vines tolerate moderate leaf loss. In a home planting, crushing larvae in rolled leaves and raking up fallen leaves can give good results.[3][2]
- Why does the damage get worse late in the season?
- First-brood larvae are few, but later broods build up and lay most of their eggs on leaves that are already rolled. Third-generation feeding can be heavy enough to defoliate vines.[2][3]
Sources
- Virginia Tech Department of Entomology (Virginia Fruit), “Grape leaffolder, Desmia funeralis (from D. G. Pfeiffer and P. B. Schultz, Major Insect and Mite Pests of Grape in Virginia, VCE 444-567).” www.virginiafruit.ento.vt.edu/leaffolder.html (accessed 2026-11-08)
- University of Florida IFAS Extension (Featured Creatures), “Grape Leaffolder, Desmia funeralis, EENY-192 (F. W. Mead and S. E. Webb, 2001; archival copy).” journals.flvc.org/edis/article/download/110442/105634/153904 (accessed 2026-11-08)
- University of California Statewide IPM Program, “Grape Leaffolder, UC IPM Pest Management Guidelines: Grape.” ipm.ucanr.edu/agriculture/grape/grape-leaffolder/ (accessed 2026-11-08)
- iNaturalist, “Desmia funeralis taxon page (order and family).” www.inaturalist.org/taxa/1106113 (accessed 2026-11-08)