# Horticulture/Prunus

Stone Fruits :
| Genus: | Prunus |
| Family: | Rosaceae |
| Type: | Trees, Shrubs |
| Disease issues: | Several, with some quite serious |
Prunus is a genus of trees and shrubs traditionally placed within the rose family, (Family Rosaceae), but now sometimes placed in its own family, the Prunaceae (or Amygdalaceae), or in a subfamily of Rosaceae, the Prunoideae (or Amygdaloideae). There are several hundred species of Prunus, spread throughout the northern temperate regions of the globe.

## Description

The flowers are usually white to pink, with five petals and five sepals. They are borne singly, or in umbels of two to six or more on racemes. The fruit of all Prunus species is a drupe with a relatively large stone. Leaves are simple and usually lanceolate, unlobed and toothed along the margin.

## Subgenera

Some treatments break the genus up into several different genera, but this segregation is not widely recognised other than at the subgeneric rank.
* Prunus subgenera:
** Subgenus Amygdalus: almonds and peaches. Axillary buds in threes (vegetative bud central, two flower buds to sides). Flowers in early spring, sessile or nearly so, not on leafed shoots. Fruit with a grove along one side; stone deeply grooved. Type species Prunus dulcis (Almond).
** Subgenus Prunus: plums and apricots. Axillary buds solitary. Flowers in early spring stalked, not on leafed shoots. Fruit with a grove along one side; stone rough. Type species Prunus domestica (Plum).
** Subgenus Cerasus: cherries. Axillary buds single. Flowers in early spring in corymbs, long-stalked, not on leafed shoots. Fruit not groved; stone smooth. Type species Prunus cerasus (Sour cherry).
** Subgenus Lithocerasus: dwarf cherries. Axillary buds in threes. Flowers in early spring in corymbs, long-stalked, not on leafed shoots. Fruit not groved; stone smooth. Type species Prunus pumila (Sand cherry).
** Subgenus Padus: bird cherries. Axillary buds single. Flowers in late spring in racemes on leafy shoots, short-stalked. Fruit not groved; stone smooth. Type species Prunus padus (European bird cherry).
** Subgenus Laurocerasus: cherry-laurels. Axillary buds single. Flowers in early spring in racemes, not on leafed shoots, short-stalked. Fruit not groved; stone smooth. Mostly evergreen (all the other subgenera are deciduous). Type species Prunus laurocerasus (European cherry-laurel).

## Uses

The genus Prunus includes the almond, apricot, cherry, peach, and plum, all of which have cultivars developed for commercial fruit production. The edible part of the almond is the seed; the almond fruit is a drupe and not a "nut". There are also a number of species, hybrids, and cultivars grown strictly as ornamentals, usually for their profusion of flowers, occasionally for leaves and bark. These ornamentals include the group that may be collectively called flowering cherries.
Because of their considerable value as both food and ornamental plants, many Prunus species have been introduced to parts of the world to which they are not native. Many of the Old World species are grown for ornament or fruit, and have been planted throughout the world; and some have become naturalised beyond their native range.

## Pests and diseases

Bacterial Leaf Spots (Shot-hole)
* Xanthomonas pruni
Fireblight
* Erwinnia amylovora
Powdery Mildew
* Podosphaera oxycanthae
Blights
* Monilinia fructicola
Leaf Spots
* Cercospora circumscissa
* Cercospora cladosporioides
* Coccomyces hiemalis
* Coccomyces lutescens
* Phyllachora beaumontii
* Phyllosticta laurocerasi
* Septoria ravenelii
Black Knot
* Apiosporina morbosa
Root Rot
* Armillaria mellea
* Clitocybe tabescens
Wilt
* Verticillium albo -atrum
Witches’ Broom
* Taphrina cerasi
Leaf Curl
* Taphrina deformans
Plum Pockets:
* Taphrina communis
Little Leaf Virus
Root Rot
* Pratylenchus penetrans
Leaf Drop
* Bordeaux mix and copper sprays may cause leaf drop.
Aphids
* Melon Aphid, Cotton Aphid: Aphis gossypii
* Leafcurl Plum Aphid: Brachycaudus helichrysi
* Black Peach Aphid: Brachycaudus persicae
* Green Peach Aphid: Myzus persicae
* Waterlily Aphid: Rhopalosiphum nymphaeae
* Apple Grain Aphid: Rhopalosiphum fitchii
* Black Cherry Aphid: Myzus cerasi
* Hop Aphid: Phorodon humuli
* Mealy Plum Aphid: Hyalopterus pruni
* Rusty Plum Aphid: Hysteroneura setariae
* Thistle Aphid: Anuraphis cardui
Scales
* Indian Wax Scale: Ceroplastes ceriferus
* Scurfy Scale: Chionaspis furfura
* Calico Scale: Eulecanium cerasorum
* Greedy Scale: Hemiberlesia rapax
* Cottony Cushion Scale: Icerya purchasi
* European Fruit Lecanium Scale: Lecanium corni
* Terrapin Scale: Lecanium nigrofasciatum
* Oystershell Scale: Lepidosaphes ulmi
* Obscure Scale: Melanaspis obscura (synonym Aspidiotus obscura)
* White Peach Scale: Pseudaulacapsis pentagona
* Cottony Hydrangea Scale: Pulvinaria hydrangeae
* Cottony Grape Scale: Pulvinaria vitis
* San Jose Scale: Quadraspidiotus perniciosus
* Euonymus scale: Unaspis euonymi
* Forbes Scale: Quadraspidiotus forbesi
Hoppers
* Planthopper: Anormensis septentrionalis
* Rose Leafhopper: Edwardsiana rosa
* Citrus Flata Planthopper: Metcalfa pruinosa
* Buffalo Treehopper: Stictocephala bisonia
* Plum Leafhopper: Macropsis trimaculata
* Privet Leafhopper: Fieberiella florii
* White Apple Leafhopper: Typhlocyba pomaria
Whiteflies
* Citrus Whitefly: Dialeurodes citri
Bugs
* Lacebugs: Corythuca
* Boxelder Bug: Leptocoris trivittatus
* Tarnished Plant Bug: Lygus lineolaris
* Western Boxelder Bug: Leptocoris rubrolineatus
Walkingsticks
Earwigs
* European Earwig: Forficula auricularia
Thrips
* Western Flower Thrips: Frankliniella occidentalis
* Pear Thrips: Taeniothrips inconsequens
Maggots
* Apple Maggot: Rhagoletis pomonella
* Black Cherry Fruit Fly: Rhagoletis fausta
* Cherry Fruit Fly: Rhagoletis cingulata
* Chokeberry Gall Midge: Contarinia virginianae
* Walnut Husk Fly: Rhagoletis completa
* Western Cherry Fruit Fly: Rhagoletis completa
Beetles
* Plum Gouger: Coccotorus scuttelaris
* Plum curculio: Conotrachelus nenuphar
* Asiatic Garden Beetle: Maladera castanea
* Japanese Beetle: Popillia japonica
* Asian Ambrosia Beetle: Xylosandrus germanus
* Cherry Curculio: Anthonomus consors
* Green Fruit Beetles: Cotinus/ spp.
* Pacific Flatheaded Borer: Chrysobothris mali
* Rain Beetles: Pleocoma spp.
* Redheaded Ash Borer: Neoclytus acuminatus
* Shothole Borer: Scolytus rugulosus
* Tenlined June Beetle: Polyphylla decimlineata
Caterpillars
* Fruittree Leafroller: Archips argyrospila
* Promethia Moth: Callosamia promethia
* Apple and Thorn Skeletonizer: Choreutis pariana
* Obliquebanded Leafroller: Choristoneura rosaceana
* Yellownecked Caterpillar: Datana ministra
* American Plum Borer: Euzophera semifuneralis
* Cecropia Moth: Hyalophora cecropia
* Fall Webworm: Hyphantria cunea
* Gypsy Moth: Lymantria dispar (syn. Porthetria dispar):
* Eastern Tent Caterpillar: Malacosoma americanum
* Western Tent Caterpillar: Malacosoma californica
* Cherry Leafminer: Nepticula slingerlandella
* Speckled Green Fruitworm: Orthosia hibisci
* Stalk Borer: Papaipema nebris
* Eastern Tiger Swallowtail: Papilio glaucus
* Cherry Leafminer: Paraleucoptera heinrichi
* Western Tentiform Leafminer: Phyllonorycter elmaella
* Tentiform Leafminer: Phyllonorycter mispilella
* Blackheaded Fireworm: Rhopobota naevana
* Redhumped Caterpillar: Schizura concinna
* Saddleback Caterpillar: Sibine stimulea
* Peach Tree Borer: Synanthedon exitiosa
* Lesser Peach Tree Borer: Synanthedon pictipes
* Apple Pandemis: Pandemis pyrusana (Pacific Northwest)
* Cherry Fruitworm: Grapholita packardi
* Cherry Bark Tortrix: Enarmonia formosana
* European Leafroller: Archips rosanus
* Eyespotted Bud Moth: Spilonota ocellana
* Leaf Crumpler: Acrobasis indigenella
* Lesser Appleworm: Grapholita prunivora
* Mineola Moth: Arcobasis tricolorella
* Navel Orangeworm: Amyelois transitella
* Oriental Fruit Moth: Grapholita molesta
* Peach Twig Borer: Anarsia lineatella
* Pistol Casebearer: Coleophora malivorella
* Redbanded Leafroller: Argyotaenia velutinana
* Resplendent Shield Bearer: Coptodisca splendoriferella
* Stinging Rose Caterpillar: Parasa indetermina
* Twotailed Swallowtail: Papilio multicaudatus
* Uglynest Caterpillar: Archips cerasivorana
* Variegated Leafroller: Platynota flavedana
Sawflies
* Pear Slug: Caliroa cerasi
* Cherry Fruit Sawfly: Hoplocampa lacteipennis
* Cherry Webspinning Sawfly: Neurotoma fasciata
* Chokeberry Sawfly: Pristophora serrula
* Peach Sawfly: Pamphilius persicus
* Plum Webspinning Sawfly: Neurotoma inconspicua
Ants
* Texas Leafcutting Ant: Atta texana
Mites
* Plum Rust Mite: Aculus fockeui
* Mite: Eriophyes emarginatae
* Southern Red Mite: Oligonychus illicis
* Mite: Phytoptus cerasicramena
* Twospotted Spider Mite: Tetranychus urticae
* Brown Mite: Bryobia rubrioculus
* European Red Mite: Panonychus ulmi
* Plum Rust Mite: Aculus fockeui
Slugs and Snails

## References

* Partial Prunus species listing: by National Genetics Resources Program