Pollen tube through wind, water or pollinators. The last step before fertilization is the growth of the pollen tube to transfer non-motile sperm to the protected egg. Pollen tubes are unique to plants and their structure had evolved over plant history. The pollen tube formation is complex and the mechanism is not fully understood, but is of great interest to scientists. Pollen is produced by the stamen, the male reproductive organ of the flower. Each pollen grain contains a vegetative cell, and a generative cell that divides to form two sperm cells. The pollen is delivered by the opening of anthers for
Pollen beetle but pollen is a major part of its diet. Several members of the Nitidulidae are similarly referred to as pollen beetles. In particular, practically all the species in the genus "Meligethes" are called pollen beetles. Of these the most notorious is probably the one now accepted as being properly called "Meligethes aeneus"/"Brassicogethes aeneus". It is called the "Brassica pollen beetle", "Rape pollen beetle" and similar names, because it first became prominent as a pest of such crops in the first quarter of the 20th century. Many species in the family Oedemeridae are similarly called "pollen beetles". For example, the Southern