Buzz pollination or sonication is a technique used by some bees, such as solitary bees to release pollen which is more or less firmly held by the anthers. The anthers of buzz-pollinated plant species are typically tubular, with an opening at only one end, and the pollen inside is smooth-grained and firmly attached. With self-fertile plants such as tomatoes, wind may be sufficient to shake loose the pollen through pores in the anther and accomplish pollination. Visits by bees may also shake loose some pollen, but more efficient pollination of those plants is accomplished by a few insect species who specialize in sonication or buzz pollination. In order to release the pollen, solitary bees are able to grab onto the flower and move their flight muscles rapidly, causing the flower and anthers to vibrate, dislodging pollen. Pollination involving vibrations is called buzz pollination. Honeybees cannot perform buzz pollination. About 9% of the flowers of the world are primarily pollinated using buzz pollination. Flower morphology Plants that rely on buzz pollination have a unique anther shape compared to other flora. In buzz pollinated plants, this process can only happen if pollinators visit the flowers to extract pollen. Only a few insect species are able to pollinate these plants. The flower morphology of buzz pollinated plants is different from that of other flora that do not use this type of pollination. The anthers are completely sealed except for a small pore at the top or have very small slits that open along the sides. The pores and slits are small enough that insects cannot easily enter the anther, but large enough pollen can exit. Because of this shape, they are often referred to as poricidal anthers. These poricidal anthers are only able to release pollen when vibrated at a specific frequency. The stigmas of these flowers are often located below the anthers. This is could be an evolutionary strategy to prevent self-fertilization, also known as selfing, by creating distance between the stigma. Plants pollinated by buzz pollination The following plants are pollinated more efficiently by buzz pollination: All species in Primula sect. Dodecatheon (shooting stars) Heliamphora Many members of the family Solanaceae Most species of the genus Solanum Eggplants Potatoes Tomatoes Buffalo bur Solanum cinereum, an Australian shrub Hibbertia Dianella (flax lilies) Many members of Ericaceae Some members of the genus Rhododendron Some members of the genus Vaccinium Blueberries Cranberries Arctostaphylos –