French Prune Trees as Overwintering Sites for the Grape Leafhopper Egg Parasite

Abstract

The mymarid wasp, <i>Anagrus epos</i> Girault, an egg parasite of the grape leafhopper, <i>Erythroneura elegantula</i> Osborn, also parasitized eggs of the prune leafhopper, <i>Edwardsiana prunicola</i> (Edwards), inhabiting French prune trees. Studies showed that the prune leafhopper completed four generations during the year. <i>Anagrus</i> overwintered within the prune leafhopper eggs laid in prune twigs. In early spring, emergence of the <i>Anagrus</i> adults coincided with the egg laying period of the grape leafhopper in nearby vineyards. Movement of <i>Anagrus</i> from prune orchards to the vineyards was determined with sticky traps used to catch <i>Anagrus</i> adults and examinations for parasitized grape leafhopper eggs on grape leaves collected at various distances away from the orchards. Results showed that <i>Anagrus</i> generated in prune orchards can migrate to vineyards and be effective in controlling the grape leafhopper.