Johannesburg City Parks and Zoo (JCPZ) has been working tirelessly to investigate infections noted in street trees as well as in trees planted in parks and open spaces.
The task team has engaged with a number of tree and insect specialists (academics, entomologists, and arbor culturists) to consult on this particular alien invasive beetle known as the Polyphagous Shot Hole Borer (PSHB), named as such due to the effect it creates, which is similar to that of a shot gun having been fired into a tree.
To date the infected trees include the following species:
|Reproductive hosts||Non-reproductive hosts|
Blackwood (Acacia melanoxylon)
Black wattle (Acacia mearnsii)
Trident (Chinese) maple (Acer buergerianum)
Boxelder (Acer negundo)
Japanese maple (Acer palmartum)
Pink flame tree (Brachychiton discolor)
Forest bushwillow (Combretum krausii)*
Coast coral tree (Erythrina caffra)*
Honey locust (Gleditsia triacanthos)
Jacaranda (Jacaranda mimosifolia)
Liquidambar/American sweetgum (Liquidambar styraciflua)
Southern magnolia (Magnolia grandiflora)
Avocado (Pearsea americana)
London Plane (Platanus x acerifolia)
Water blossom pea (Podalyria calyptrata)*
Fountain bush (Psoralea pinata)*
Pin oak (Quercus palustris)
English Oak (Quercus robur)
Castor bean (Ricinus communis)
White willow (Salix alba)
Cape willow (Salix mucronata)*
Monkey-thorn (Senegalia galpinii)*
Swamp cypress (Taxodium distichum)
Sweet thorn (Vachellia karoo)*
Paper bark thorn (Vachellia sieberiana var. woodii)*
English elm (Ulmus minor = procera)
Chinese elm (Ulmus parvifolia)
Viburnum (Viburnum sinensis)
Keurboem (Virgilia divaricata)*
Grapevine (Vitis vinifera)
Pride of De Kaap (Bauhinia galpinii)*
Butterfly orchid tree (Bauhinia purpurea)
Silver birch (Betula pendula)
False olive (Buddleja saligna)*
Cape chestnut (Calodendrum capense)*
Wild laburnum - Geelkeurboem (Calpurnia aurea)*
Common camellia (Camellia japonica)
Pecan nut (Carya illinoinensis)
Kapok (Ceiba pentandra)
Camphor (Cinnamomum camphora)
Lemon (Citrus limon)
Orange (Citrus sinensis)
River bushwillow (Combretum erythrophyllum)*
Septee tree (Cordia caffra)*
Cabbage tree - Kiepersol (Cussonia spicata)*
Star apple (Diospyros dichrophylla)*
Monkey plum (Diospyros lycidioides)*
Cape ash (Ekebergia capensis)*
Loquat (Eriobotrya japonicum)
Aloe coral tree (Erythrina livingstoniana)
Common coral tree (Erythrina lysistemon)*
River red gum (Eucalyptus camaldulensis)
Common fig (Ficus carica)
Natal fig (Ficus natalensis)*
European ash (Fraxinus excelsior)
Cross berry (Grewia occidentalis)*
Spike thorn (Gymnosporia buxifolia)*
Tree fuschia (Halleria lucida)*
Wild plum (Harpephyllum caffrum)*
Syringa (Melia azedarach)
Honey flower - Kruidjie-roer-my-nie (Melianthus major)*
Mulberry (Morus sp.)
Forest elder (Nuxia floribunda)*
Wild olive (Olea europea subsp. africana)*
American plane (Platanus occidentalis)
Californian plane (Platanus racemosa)
Frangipani (Plumeria rubra)
Oteniqua yellowwood (Podocarpus (Afrocarpus) falcatus)*
Henkel's yellowwood (Podocarpus henkelii)*
Lombardy poplar (Populus nigra)
Forest sugar bush (Protea mundii)*
Black plum (Prunus nigra)
Peach (Prunus persica)
Guava (Psidium guajava)
Cape-beech (Rapanea melanophloeos)*
Pepper tree (Schinus molle)
Weeping boerbean - Huilboerboon (Schotia brachypetala)*
The PSHB infestation is a national problem, and the current action plan is focused on gathering and analyzing as much information as possible, as well as working in collaboration with the national Department of Agriculture, Forestry and Fisheries (DAFF) who are taking a lead in dealing with this issue – as well as other organizations and private institutions.
This includes continuously identifying trees that are infected and researching a sustainable solution to dealing with this problem. In this regard, JCPZ through the City of Johannesburg joined the Cities4Forests Group - the World Resource Institute Forum dealing with urban forestry and related matters.
A workshop is being planned with several international and UN based organizations in a quest to develop a specific strategy for the City.
Key implementable action plans for which resources were acquired include:
• Removal of dead trees.
• Ensuring data on what killed the trees is accurate – this is to ensure cases of PSHB are accurately recorded.
• Proper disposal of these trees so that no further contamination happens.
• Engagement with PIKITUP on the volume of green waste that will be generated.
• Education and engagement with communities in the month of September and October in areas where trees are being planted for Arbor month.
• Risk profile compilation by the Stakeholder unit of JCPZ.
• Development of capacity within the City to manage the phenomenon through academic research and skills insourcing.
Scientifically based data is provided by agencies such as the Forestry and Agricultural Biotechnology Institute (FABI), various universities and the JCPZ team on the ground in mapping and plotting the areas where such infections are reported in public open spaces and street trees.
JCPZ has been approached by various stakeholders with possible chemical solutions. JCPZ can only engage in discussing these solutions if the products are legally registered for this purpose.
The Department of Agriculture, Forestry and Fisheries published communication to inform stakeholders about the infestation. They stated that chemical control (injecting infested trees with fungicides and insecticides) may prove to be effective to control this tiny beetle and its fungus, but may be expensive. They have also requested that plant materials showing similar symptoms, or infested trees, should be reported to the relevant authorities or alternatively cut down and chipped. JCPZ is engaging with Pikitup to establish designated sites.
The selection is dependent on feasibility studies and available budget. In this regard, the City is requesting the reporting of suspicious trees in Johannesburg to the Whatsapp number: 064 756 2736 by sending the following:
Step 1: To send a WhatsApp Location Pin:
• Turn on phone location
• Open WhatsApp
• Select Attach
• Select Location
• Select Send Your Current Location
• Send photos
Step 2: Take photos of suspected trees from several distances. Include photos of:
• The trunk or symptomatic branches
• The symptoms (close-up)
• The entry/exit hole, if visible, with a ballpoint pen for scale (remove gumming or exudate if necessary)
• If fusarium dieback is observed, include a picture of the entire tree
Councillor Nonhlanhla Sifumba
Member of the Mayoral Committee for Community Development
City of Joburg
All media enquiries can be sent to:
Ms. Jenny Moodley
Spokesperson: Johannesburg City Parks and Zoo
T: 011 712-6600/082 8030 748