Polyphagous Shot Hole Borer

The Shot Hole Borer Beetle is destroying our Urban Forest

The polyphagous shot hole borer (pshb) is a type of amborsia beetle that is currently infesting over 200 tree species around the country.

This tiny beetle, the size of a sesame seed does not itself kill the tree, rather
it is the fungus that accompanies the beetle and grows in the borer tunnel.

This fungus impacts the trees vascular system and inhibits the flow of water and nutrients within the tree.

How to identify symptoms:

As the beetle is so tiny it is often not seen, therefore it is better to look for signs of infestation. Symptoms vary from species to species.

For more information, visit FABI

REPRODUCTIVE HOST TREES¹
Exotic species		Native SA species
Latin name	Common name	Latin name	Common name
Acacia melanoxylon	Blackwood	Combretum krausii	Forest bushwillow
Acacia mearnsii	Black wattle	Erythrina caffra	Coast coral tree
Acer buergerianum	Trident (Chinese) maple	Podalyria calyptrata	Water blossom pea
Acer negundo	Boxelder	Psoralea pinata	Fountain bush
Acer palmatum	Japanese maple	Salix mucronata	Cape willow
Brachychiton discolor	Pink flame tree
Gleditsia triacanthos	Honey locust
Liquidambar styraciflua	American sweetgum
Magnolia grandiflora	Southern magnolia
Pearsea americana	Avocado
Platanus x acerifolia	London Plane
Quercus palustris	Pin oak
Quercus robur	English Oak
Ricinus communis	Castor bean
Salix alba	White willow

NON-REPRODUCTIVE HOST TREES²
Exotic species		Native SA species
Latin name	Common name	Latin name	Common name
Bauhinia purpurea	Butterfly orchid tree	Bauhinia galpinii	Pride of De Kaap
Betula pendula	Silver birch	Buddleja saligna	False olive
Camellia japonica	Common camellia	Calodendrum capense	Cape chestnut
Carya illinoinensis	Pecan nut	Calpurnia aurea	Geelkeurboom
Ceiba pentandra	Kapok	Combretum erythrophyllum	River bushwillow
Cinnamomum camphora	Camphor	Cordia caffra	Septee tree
Citrus limon	Lemon	Cussonia spicata	Cabbage tree/ Kiepersol
Citrus sinensis	Orange	Diospyros dichrophylla	Star apple
Eriobotrya japonicum	Loquat	Diospyros lycidioides	Monkey plum
Erythrina livingstoniana	Aloe coral tree	Ekebergia capensis	Cape ash
Eucalyptus camaldulensis	River red gum	Erythrina lysistemon	Common coral tree
Ficus carica	Common fig	Ficus natalensis	Natal fig
Fraxinus excelsior	European ash	Grewia occidentalis	Cross berry
Jacaranda mimosifolia	Jacaranda	Gymnosporia buxifolia	Spike thorn
Melia azedarach	Syringa	Halleria lucida	Tree fuschia
Morus sp.	Mulberry	Harpephyllum caffrum	Wild plum
Platanus occidentalis	American plane	Melianthus major	Honey flower/ Kruidjie-roer-my-nie
Platanus racemosa	Californian plane	Nuxia floribunda	Forest elder
Plumeria rubra	Frangipani	Olea europea subsp. africana	Wild olive
Populus nigra	Lombardy poplar	Podocarpus falcatus	Outeniqua yellowwood
Prunus nigra	Black plum	Podocarpus henkelii	Henkel’s yellowwood
Prunus persica	Peach	Protea mundii	Forest sugar bush
Psidium guajava	Guava	Rapanea melanophloeos	Cape beech
Schinus molle	Pepper tree	Schotia brachypetala	Weeping boerbean/ Huilboerboon
Taxodium distichum	Swamp cypress	Prunus africana	Red stinkwood
Ulmus minor = procera	English elm	Senegalia (Acacia) galpinii	Monkey-thorn
Ulmus parvifolia	Chinese elm	Vachellia (Acacia) karroo	Sweet thorn
Viburnum sinensis	Viburnum	Vachellia (Acacia) sieberiana var. woodii	Paper bark thorn
Vitis vinifera	Grapevine	Virgilia divaricata	Keurboom
¹Host trees in which both the beetles and the fungus establish, and where the beetle successfully reproduce. In most cases the reproductive hosts will eventually be killed by the fungus.
²Host trees that are attacked by the beetle and where the fungus establishes, but where the beetle does not successfully breed. The fungus might, or might not cause disease and kill the trees.

Watch the video below:

In South Africa, some Evergreens are also affected

HELP STOP THE SPREAD
Infested and dead trees are a breeding ground for shot hole borer (PSHB). Recent tests Indicate that ONE heavily infested tree contains over 100,000 beetles. Dead trees need to be removed and disposed of responsibly.

How to dispose of
infested plant material:

Cut infested branches into small pieces.

Put into refuse bags and seal.

Keep in direct sunlight, the heat from the
sun will kill the insect and its larvae.

Or

Burn on site.
(Large quantities of infested wood may not be burnt in an urban area)

Or

Consult a tree specialist.

Or

Chip and compost.

Further Reading:
The Conversation A tiny beetle and its deadly fungus is threatening South Africa’s trees by Wilhelm de Beer Read Here
FABI Research Feature *The Polyphagous Shot Hole Borer* Read Here
Australasian Plant Pathology The polyphagous shot hole borer (PSHB) and its fungal symbiont Fusarium euwallaceae: A new invasion in South Africa by T.Paap et al Read Here

Polyphagous Shot Hole Borer

Watch the video below:In South Africa, some Evergreens are also affected

How to dispose ofinfested plant material:

Or

Or

Or

Further Reading:

Watch the video below:

In South Africa, some Evergreens are also affected

How to dispose of
infested plant material: