Background
Lobesia botrana (Lepidoptera: Tortricidae), also known by the common name European grapevine moth, is currently regulated as a quarantine pest by Canada:
- D-13-03: Phytosanitary Import Requirements to Prevent the Introduction of Lobesia botrana, the European Grapevine Moth
- D-95-08: General import requirements for fresh temperate fruits from the world
It is also regulated as a quarantine pest by the United States, where it has been successfully eradicated. Other countries that regulate this pest are Argentina, Australia, Brazil, Chile, China, Costa Rica, Dominican Republic, Ecuador, Egypt, Indonesia, Korea, Kosovo, Mexico, Myanmar, Nepa, New Zealand, Nicaragua, Peru and Taiwan.
Host
Lobesia botrana is a polyphagous insect feeding on at least 40 plant species belonging to 27 families. Its preferred commercial host is Vitis vinifera (grape). However, it may also feed on several other plants or plant products, including Daphne gnidium (spurge flax), Olea europaea (olive), Prunus spp. (stone fruit), Ribes spp. (currant, gooseberry), Salvia rosmarinus [syn. Rosmarinus officinalis](rosemary), Rubus caesius (European dewberry), Rubus fructicosus (European blackberry), and Urginea maritima (sea squill).
Distribution
- Africa: Algeria, Egypt, Eritrea, Ethiopia, Kenya, Libya, Morocco, Tunisia
- Asia: Armenia, Azerbaijan, Georgia (Republic of), Iran, Iraq, Israel, Jordan, Kazakhstan, Lebanon, Syria, Tajikistan, Türkiye, Turkmenistan, Uzbekistan
- Europe: Albania, Austria, Belarus, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, France, Germany, Greece, Hungary, Italy, Kosovo, Lithuania, Luxembourg, Malta, Moldova, Montenegro, Netherlands, North Macedonia, Poland, Portugal, Romania, Russia, Serbia, Slovakia, Slovenia, Spain, Switzerland, Ukraine, United Kingdom
- The Americas: Argentina, Chile
Biology
Lobesia botrana is a multivoltine species (that is, with many generations per year) and a diapause stage. The number of generations depends on latitude, climate, and microclimate. There are two generations per year in the northern limit of its distribution and 3 to 5 generations in its more southern distribution range.
The female moth of the first generation lay eggs singly or in groups of 2 to 3 on flower buds, blossoms, or stems of host plants. Those of the second and third generations deposit eggs singly on individual berries. Eggs hatch in 7 to 11 days in the spring and in three to five days in the summer.
Larvae of the first generation feed on flower buds and flowers, while the later generations feed on ripening and mature fruits. Pupae of the non-overwintering generations occur inside fruit or in folded leaves. Pupae of the overwintering generation are found under bark and in crevices of stems and trunks of woody plants; they can also be found in the soil or under leaf litter near host plants. Adults first emerge in April or May and the final generations emerge in August to September. The lower temperature threshold for egg, larval and pupal development is approximately 8°C.
Identification
Adults (figures 1, 2) are 6-8 mm long with a wingspan of 10-13 mm. Males and females are similar in appearance but differ in hindwing colour; white in males and dark gray to brown in females. Forewings are cream with brown and purplish gray markings, a dark brown median band, and a border of olive-brown hairs. The head, thorax and abdomen are cream with brownish-gray markings. The antennae are filiform (thread-shaped).
Pupae (figures 3, 4) are 5-9 mm long, slender and cream to dark brown in colour. The abdomen has well-developed dorsal spines, the head is unmodified, without projections, and the cremaster (the structure used by the insect to attach the pupa to its support) is fan-shaped. The pupal cocoon consists of whitish-gray silk threads, and is 8-10 mm long, 3 mm wide.
Larvae (figures 5, 6, 7, 8) are 10-12 mm long and 2 mm wide when fully mature. There are usually five larval instars that can be distinguished by the width of the head capsule and length of the mandibles. The head is yellowish-brown, the abdomen varies from greenish-yellow to light brown, the thoracic legs are brown, and the anal plate is yellowish-brown. An anal comb is present with 6-8 prongs.
Eggs (figures 9, 10) are lentil-shaped and around 1 mm long, 0.6 mm wide. Freshly laid eggs are initially pale yellow, later becoming gray and translucent.
Signs and symptoms
Damage from larval feeding is the most obvious sign of pest presence. Partially eaten or shrivelled fruits often accompanied by mould or fruit rot are key indicators. The presence of larval webbing (clustering a few flowers together) and larval frass may also be visible (figure 11). Larvae feed inside fruit, so damage to the fruit may only be noticed when the larvae are large, or populations are high. Exit holes may be found on the fruit after internal feeding. Larval damage on growing points, shoots or leaves of the plant is unusual. Overwintering pupae (in cocoons) can be found under bark and in crevices on the stems or trunks of nursery stock or grapevine plants.
