The bees (and also other insects) play a minor role in the fertilisation of the vine, this is mainly done by self-pollination resp self-pollination (see also in detail under flowering). Bees occur to an insignificant extent as vine pests. The mouthparts of the bee are lick-sucking. The very small upper jaws chew, the lower jaws and the lip palps form a suction tube with which nectar can be taken from the flower. In contrast, wasps do not have a proboscis for sucking up nectar, but biting mouthparts with paired upper jaws (mandibles) and lower jaws. In contrast to wasps, bees cannot bite open the skin of grapes, but can only press on fine hairline cracks with their head, where they then suck up the sweet juice that emerges. However, they also participate in the preliminary work of the berries bitten by wasps. See also under beneficial insects and vine enemies.