Source: Jack K. Clark, University of California IPM Statewide Program
Common Name: European Grapevine Moth (EGVM)
Latin Name: Lobesia botrana
Main Host(s): Preferred host is grape, but occurs on kiwi, raspberry, apple, pomegranate and wild hosts such as Virginia creeper, etc.
Long an important pest in grape production throughout Europe, European grapevine moth (EGVM) (Lobesia botrana) made its way into Chile and the premium wine grape areas of California for the first time in 2009, causing great concern. In Europe, EGVM can be found together with another grape berry moth, i.e. Eupocilia (Clysia) ambiguella.
There are generally two to four generations of EGVM per year. The first generation occurs between early April and mid-May in the U.S. The second (adult moth flight) appears in mid-June to late July, and the third and most critical generation appears in late August until late September.
The female lays single eggs 2-3 at a time on flower buds and fruiting structures. When the eggs develop, the black head of the developing larvae can be seen through the translucent egg covering (blackhead stage). The eggs hatch in 3-10 days depending on temperature. The final larval generation pupates for overwintering in the soil or under bark.
The first larval generation of EGVM is usually of no concern as feeding occurs on flower buds. Damage by the second larval generation feeding on small berries can become economically impactful, but the third generation larvae cause the greatest damage. This generation feeds on berries after veraison, exposing berries and clusters to bunch rot (Botrytis cinerea) and other secondary fungi.
Monitoring for EGVM eggs in the vineyard should begin immediately after moths are observed in sex pheromone monitoring traps. Beneficial insect predators and parasites can play a significant role in first generation EGVM control. Despite the threat from later larval generations, growers have learned that through careful scouting and judicious application of the Bacillus thuringiensis (Bt) insecticide DiPel®, the pest’s potentially serious damage could be limited. All generations can be controlled using DiPel alone or in tank mix or rotation with chemical insecticides. DiPel can also be used with pheromone dispensers used in mating disruption programs. DiPel application should occur when the majority of the eggs are at the blackhead stage with a second application 7-10 days after the first, if necessary.