Research led by Fanny Vogelweith of the University of Burgundy in Dijon, France, and INRA Bordeaux-Aquitaine in France indicates the moths are better adapted and more successful in certain French wine-growing regions than in others because of the grape variety and the presence or absence of their natural enemies.
Vogelweith's team assessed how immune differences within the moth's populations are influenced by its host plants and natural enemies.
The European grapevine moth is a major vineyard pest in Europe because of its geographical distribution. When its larvae feed on grapes, they become more susceptible to fungi, the researchers said.
The research team collected and measured larvae -- and any parasites found on the larvae -- from different grape varieties from vineyards in six French viticulture regions, Vogelweith said.
Among other things, the team found a noticeable geographical variation in the immune defense and the level of parasitism among populations of the grapevine moth. If more parasites were found in a vineyard, the moth focused more on its immune defense rather than body growth, the research indicated.
Vogelweith said more research would be necessary to clarify the influence of grape variety on the immune system.
"The findings emphasize the roles of host plants and parasitoids as selective forces that shape host immune functions under natural conditions," Vogelweith said. "Studies such as these are central to understanding natural variations in immune functions, and the selective forces beyond."
The findings were published Wednesday in the Science of Nature.