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How to identify it
- Adult females are about 1/8 inch long, soft, oval, flat and clearly segmented, with a pinkish body that shows through a coat of white, mealy wax.[1]
- The wax forms short filaments around the edge of the body (ScaleNet counts 18 pairs). They are shorter than the filaments on the other mealybugs found on grapes, and there are no long tail filaments.[1][2][3]
- It resembles citrus mealybug and has a dark stripe down its back.[2]
- Adult males are winged and dark brown, only about 1.5 mm long, and fly short distances to find mates. They are smaller than adult thrips, so identifying them takes a dissecting microscope.[1][3]
Look-alikes
| Look-alike | How to tell them apart |
|---|---|
| Grape mealybug and obscure mealybug (Pseudococcus species) | Slightly larger, with longer wax filaments. They stay on the aboveground parts of the vine and do not lay eggs on leaves above the fruit zone, while vine mealybug does.[1] |
| Citrus mealybug (Planococcus citri) | A close relative with short, even filaments that is mostly a pest of citrus, landscape shrubs and indoor plants.[2][3] |
| Longtailed mealybug | Has tail filaments longer than its body and is found only on aboveground parts of grapevines.[1][2] |
Where it lives
In the United States it is a pest of California vineyards, where UC IPM reports it in every major grape-growing region. ScaleNet's catalogue also lists records from nine southern and eastern states, from Maryland to Florida and Texas, most of them from a 1956 study. North American populations likely came from the Middle East, and California and Mexico appear to share a single invasion.[1][3]
Biology and life cycle
It does not go dormant in winter. Coastal vineyards have two to three generations a year, and the lower San Joaquin Valley has five to seven.[1]
In the North Coast only nymphs are found in winter, tucked under bark at the graft union, on pruning wounds and below the spurs. In regions with sandy soils it spends the winter almost entirely on the roots, and elsewhere eggs, crawlers, nymphs and adults overwinter under bark, inside buds and on roots.[1]
As spring warms, populations climb from the roots and trunk into the cordons and canopy, and by late spring and summer they can be on every part of the vine, including leaves well above the fruit, where females lay eggs. Ants may carry mealybugs from the roots to the canopy and tend them there.[1]
Females and nymphs cannot fly. They are carried to new places by people, equipment, wind and birds, or arrive on infested vines at planting.[1]
In California it feeds mostly on grapevines. In other countries it is also a pest of fig, date palm, apple, avocado, citrus and a few ornamentals, and it is a major grape pest in the Mediterranean region, South Africa, Pakistan and Argentina.[1][3]
Damage and signs
- Feeding produces honeydew that drips onto bunches and other parts of the vine, where black sooty mold grows on it. If no ants are present, a heavily infested vine can be coated with honeydew that looks like candle wax.[1]
- The mealybugs themselves infest the bunches, which makes the fruit unfit to eat.[1]
- It spreads grapevine leafroll-associated viruses, and studies have estimated yield losses from leafroll disease spread by this mealybug at as much as 30 to 40 percent in California vineyards.[1][3]
Health risk
The sources treat it only as a plant pest; none mentions bites or any risk to people or pets.[1][3]
Control
Prevention
Researchers who studied its spread in Napa County concluded that quarantine and treatment zones of 250 meters around each detection are likely enough to take in most local establishment and spread.[4]
Pheromone mating disruption can replace or supplement insecticides. It works best over 10 acres or more, after insecticides have first brought numbers down, and has worked better in northern California, where there are fewer generations a year.[1]
Sanitation
Keep contaminated equipment, vines, grapes and winery waste away from clean vineyards, steam-clean equipment before moving it into clean blocks, don't spread infested stems or pomace in the vineyard, and cover pomace piles with clear plastic for several weeks.[1]
Traps and physical control
Prune so clusters don't hang directly on the cordon. Where mealybugs overwinter on the roots, a band of sticky barrier material on duct tape wrapped around the trunk (with the bark removed) may slow crawlers climbing the vine in spring.[1]
Biological control
Parasites of grape and obscure mealybugs don't attack vine mealybug, so the parasitic wasp Anagyrus pseudococci was imported and released in California. It works best late in the season because it doesn't emerge until about bloom; growers can buy and release it early, and controlling ants helps it. In coastal areas, mealybug destroyer and Hyperaspis lady beetles feed on its eggs and crawlers, and predatory midge larvae eat the eggs.[1]
Pesticides
In vineyards where it is found, treatment is recommended. With light infestations, one insecticide application in spring or at bloom is often enough for the season, while heavily infested, late-harvested table grapes may need three or more. Repeated oil sprays approved for organic use can suppress it in wine and raisin grapes but are not used on table grapes.[1]
When to call a professional
Several mealybugs infest grapes and their management differs, so confirm the species first: put the largest mealybugs you can find in alcohol or a sealed bag and take them to a UC Cooperative Extension farm advisor or the county Agricultural Commissioner.[1]
Finding vine mealybug in a vineyard
Look on the roots and lower crown in winter (in sandy soils), on the crown and trunk in spring, on cordons, canes and lower leaves from bloom on, and on clusters once fruit is present, especially after veraison.[1]
Ants and honeydew point the way: Argentine and gray ants tend vine mealybugs, and in summer the honeydew looks like melted candle wax on clusters, trunks and cordons, with lower leaves turning shiny and sticky. Later, sooty mold turns the vine's woody parts greenish black.[1]
Pheromone traps catch males from as far as a quarter mile away. UC IPM suggests small red delta traps hung in the cluster zone, two per 20 to 40 acres, checked every two weeks through November.[1]
Common questions
- How is vine mealybug different from other grape mealybugs?
- It is a little smaller, pinkish under its wax, and has short filaments with no long tails. It also lives on roots and lays eggs on leaves, which the other grape mealybugs don't do.[1][2]
- How does vine mealybug get into a new vineyard?
- The females and nymphs can't fly, so they are carried in by people, equipment, wind and birds, or arrive on infested vines at planting. UC IPM advises keeping contaminated equipment, vines, grapes and winery waste away from clean vineyards.[1]
- Can vine mealybug spread grape diseases?
- Yes. Like grape, obscure and longtailed mealybugs, it can transmit grapevine leafroll-associated viruses.[1]
Sources
- University of California Statewide IPM Program, “Grape Pest Management Guidelines: Vine Mealybug.” ipm.ucanr.edu/agriculture/grape/vine-mealybug/ (accessed 2026-11-09)
- University of California Statewide IPM Program, “Pest Notes: Mealybugs (UC ANR Publication 74174).” ipm.ucanr.edu/home-and-landscape/mealybugs/ (accessed 2026-11-09)
- ScaleNet (scale insect database begun at the USDA ARS Systematic Entomology Laboratory), “ScaleNet catalogue: Planococcus ficus (Signoret).” scalenet.info/catalogue/Planococcus%20ficus/ (accessed 2026-11-09)
- Oxford University Press for the Entomological Society of America (Environmental Entomology), “Quantifying Planococcus ficus (Hemiptera: Pseudococcidae) invasion in northern California vineyards to inform management strategy (Schartel et al. 2021, Environmental Entomology 50:138-148).” doi.org/10.1093/ee/nvaa141 (accessed 2026-11-09)
- iNaturalist, “Planococcus ficus taxon page (order and family).” www.inaturalist.org/taxa/684061 (accessed 2026-11-09)