2015 Volume 57 Pages 63-67
The yellow tea thrips, Scirtothrips dorsalis HOOD, is a serious grapevine pest. Mulching reflective sheets (e.g., TYVEC®, DuPont) on the ground around fruit trees is known to be effective in reducing damage from this pest, for example in citrus orchards. In the case of espalier grapevine fields mulched with reflective sheets, the reflected light easily reaches the leaves and fruits, and damage by S. dorsalis may decrease, compared to the case of typical lattice-like shelves covered with leafy stems, which prevent sunlight from reaching the ground. We investigated the damage to ripe berries of the espalier grapevine (cv. “Neo Muscat”) in the case of mulching with reflective sheets. The damage indices for the stems and fruit clusters from the mulched trees were lower than those from unmulched trees without pesticide application, but higher than those from unmulched trees sprayed with insecticide (cartap). The density of S. dorsalis in the mulched trees was apparently lower than in the unmulched trees. The phytoseiid mite, Euseius sojaensis Ehara, known as a native predator of S. dorsalis, was also observed to be abundant on matured leaves of mulched trees. These results indicate that, for espalier grapevine, mulching reflective sheets is effective in reducing fruit damage by S. dorsalis.