Sorbus minima Sorbus minima Sorbus minima, commonly known as the lesser whitebeam or least whitebeam, is a shrub belonging to the subgenus "Aria" (whitebeams) in the genus "Sorbus". It is endemic to Wales where it grows at a few sites in Breconshire. It is an apomictic microspecies which reproduces asexually and so is reproductively isolated from its close relatives such as the Swedish whitebeam, "S. intermedia". It probably originated as a hybrid between the rock whitebeam ("S. rupicola") and the rowan ("S. aucuparia"). It was first discovered in 1893 by Augustin Ley, the vicar of Sellack in Herefordshire who travelled widely in
Aphis pomi "A. pomi", especially at high temperatures. Besides occurring on apple ("Malus domestica"), "Aphis pomi" infests other plants in the family Rosaceae including pear ("Pyrus communis "), hawthorn ("Crataegus monogyna"), medlar ("Mespilus germanica"), quince ("Cydonia oblonga"), mountain ash ("Sorbus aucuparia"), rose ("Rosa") and spiraea ("Spiraea"). It is an autoecious species, completing its life cycle on a single host species. Overwintering eggs hatch in spring and the aphids colonise the growing tips of the shoots causing the edges of the leaves to curl. These aphids are all viviparous females and give birth to other wingless aphids by parthenogenesis. In June some winged