European grapevine moth (Lobesia botrana)

Synonyms: Polychrosis botrana, Tortrix botrana

Common Names: European grapeworm moth, European grape moth, grapevine moth

Description:

European grapevine moth (Lobesia botrana) is a small moth from southern Europe and the Mediterranean whose caterpillars bore into the flowers and fruit of grapes [1][2]. It is one of the most damaging grape pests in its native range, and it was found in California vineyards in 2009 before being eradicated from the United States in 2016 [1]. MISIN tracks it as an early-detection target, so a new arrival in the Midwest can be caught and reported before it takes hold [1].

Identification:

The European grapevine moth is small and easy to overlook. The adult is only about a third of an inch long, with a wingspan near half an inch [2]. Its front wings are a mottled tan-cream marked with gray-blue, brown, and black blotches, and at rest it folds them in a bell shape over its body [2]. The caterpillars are the damaging stage: they bore into grape flower clusters and berries, web them together, and leave behind frass (droppings), and the damaged berries often rot afterward [2].

The clearest signs are on the fruit, not the moth. In spring, look for flower buds webbed together; from summer into fall, look for berries that are hollowed, bound with silk, and filled with frass, and for clusters that begin to rot [2]. Because the adults are tiny and fly at night, they are usually found with pheromone traps rather than by eye, and they closely resemble several native moths ? so any suspected sighting needs expert or lab confirmation [3][4].

At-a-glance cues:

1. Small moth, about ? inch long, with mottled tan-cream forewings marked with gray-blue, brown, and black [2]
2. Wings folded in a bell shape over the body at rest [2]
3. Grape flower clusters webbed together in spring; berries hollowed, webbed, and frass-filled from summer into fall [2]
4. Damaged clusters often develop gray mold or other rot [2]

Hosts:

European grapevine moth is native to southern Europe and the Mediterranean and is found across the wine-growing regions of Europe, North Africa, and western Asia; it has also reached Japan, Chile, and Argentina [1][2]. Its main host is grapevine, where it does the most damage, but it feeds on a wide range of fruiting plants, including spurge laurel, blackberry, currants, gooseberry, olive, cherry, plum, persimmon, kiwi, and pomegranate [2]. It is not established in the United States: it was found in California in 2009 and declared eradicated there in 2016, and it is not currently known to occur in the Midwest [1].

Life Cycle:

European grapevine moth spreads from place to place mainly when people move infested fruit, plants, or packing material ? eggs and tiny caterpillars can ride along on grapes or nursery stock [1][4]. Within a vineyard or garden, the adults fly at night and lay eggs one at a time on or near flower clusters and berries [2].

The moth goes through two to three generations a year, with sometimes a partial fourth in warm climates [2]. The first generation feeds on flower clusters in spring; the second feeds on green berries in summer, hollowing them out; and the third, in late summer and fall, does the most damage by feeding and webbing inside ripening bunches [2]. It survives the winter as a pupa in a silk cocoon tucked under bark or in cracks, and the adults emerge in spring once the weather warms [2]. For early detection, the key window is the growing season ? spring flowering through fall harvest ? when both the caterpillars and their feeding damage are present [2][4].

Impact and Damage:

European grapevine moth is first and foremost a crop pest, so the impact a homeowner would notice is to backyard grapes and fruit. The caterpillars feed inside grape flower clusters and berries, and their feeding wounds open the fruit to gray mold (Botrytis) and other rots that can spoil a whole bunch [2][3]. Heavy infestations cut both the amount and the quality of the fruit [3]. It is not a risk to human health and does not harm pets [2].

The larger concern is economic and agricultural. In its native range it is considered one of the most serious pests of wine and table grapes, and it attacks many other fruit crops as well [2][3]. Because of that threat, its 2009 arrival in California triggered a multi-year federal and state eradication program ? quarantines, intensive trapping, and coordinated control across the affected region ? that successfully removed it by 2016 [4]. Keeping it out of new regions such as the Midwest protects vineyards, orchards, and the other plants it can use as hosts [1][4].

Similar species:

European grapevine moth is a small leaf-rolling moth (a tortricid) that looks like several native and introduced moths. Reliable identification usually needs an expert or a lab, which is why suspected sightings should be reported rather than judged by eye [3][4].

Grape berry moth (Paralobesia viteana) is the native North American look-alike and the easiest one to confuse it with [4]. Its caterpillars also bore into grape berries, and the adults are so similar that they are hard to tell apart by wing color alone, needing close examination under magnification [4]. Grape berry moth is already common across the eastern United States, while European grapevine moth is not established here [4].

Light brown apple moth (Epiphyas postvittana) is another non-native leaf-rolling moth that feeds on grapes and many other plants and is also a regulated pest [4]. Like European grapevine moth, it is small and mottled brown and is monitored with traps, so the two are easy to mix up without expert checking [4].

Omnivorous leafroller (Platynota stultana) is a small leafroller that also webs and feeds in grape clusters [4]. Its damage can look similar, but it tends to roll and tie leaves as well as feed in the fruit, and it too needs expert confirmation to separate from European grapevine moth [4].

Monitoring and rapid response:

Signs to watch for:

1. On backyard grapes and fruit: flower clusters webbed together in spring; berries that are hollowed, webbed with silk, and filled with frass from summer into fall; bunches starting to rot [2]
2. Small tan-cream mottled moths near grapes ? usually found only in pheromone traps, not by eye [2][4]
3. Keep in mind it is not known to be established in the Midwest, so any find is worth reporting [1]

What you can do:

1. If you grow grapes or fruit and find webbed, frass-filled, or rotting clusters, seal a few affected clusters (with any caterpillars) in a bag for identification rather than leaving them out [2][4]
2. Clean up and bag fallen and shriveled (mummified) fruit at the end of the season to remove overwintering sites, and put it in the trash, not the compost [2]
3. Do not move grapes, grapevines, or fruit out of an area where this pest is suspected ? people moving infested fruit and plants is the main way it spreads [1][4]
4. For volunteer crews and land managers: support the coordinated trapping and survey efforts led by agricultural agencies, and prioritize reporting and confirming suspect finds early, because this pest is handled through area-wide programs rather than spot treatment [4]

When to call a professional:

1. Any suspected European grapevine moth should be reported to agricultural authorities ? confirmation and any response are handled through federal and state programs, not by individual treatment [1][4]
2. Established or repeat infestations on a property, where expert survey and coordinated control are needed [4]
3. For chemical control options, contact a licensed applicator or your local cooperative extension office.

Report sightings to MISIN. Help track this species' spread by submitting observations through the MISIN web site or the MISIN mobile app (Android, iOS, Windows, and macOS). Photos at multiple angles paired with a precise GPS location are the most valuable data for confirming new occurrences and triggering rapid-response review.

Credits:

1. National Invasive Species Information Center (USDA National Agricultural Library). European Grapevine Moth (Lobesia botrana). invasivespeciesinfo.gov
2. Texas Invasive Species Institute (Texas State University System). European Grapevine Moth ? Lobesia botrana. tsusinvasives.org
3. Ioriatti C, Anfora G, Tasin M, et al. (2011). "Chemical Ecology and Management of Lobesia botrana (Lepidoptera: Tortricidae)." Journal of Economic Entomology 104(4):1125?1137. semanticscholar.org
4. Simmons GS, Varela L, Daugherty M, et al. (2021). "Area-Wide Eradication of the Invasive European Grapevine Moth Lobesia botrana in California, USA." In: Area-Wide Integrated Pest Management: Development and Field Application. CRC Press. semanticscholar.org

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