Thrips rasp (by puncturing individual surface cells and sucking cellular contents) the surface of flower and fruit tissues as they feed. Their feeding can weaken and deform flowers and reduce flower viability. The most visible damage is caused when they rasp the surface of the fruit in areas where two fruit come in contact or when a leave lies up against the fruit. This damage is cosmetic only and does not extend beneath the fruit skin.
Photo Source: Michael Bush, WSU Extension, Yakima, WA