Die Polyphagous Shot Hole Borer is onlangs vir die eerste keer in Suid-Afrika opgemerk. Die kewer is die draer van ‘n fussarium-swaminfeksie wat bome kan aanval.
Dit is as op 80 verskillende boomspesies geïdentifiseer en veral neutboere en avokadoboere is gevra om op die uitkyk te wees vir die pes. ‘n Webwerf is begin om boere te help.
Besoek http://polyphagous-shot-hole-borer.co.za/ vir meer inligting en neem asseblief deel aan die inligtingsveldtog. Die maklikste manier om die piepklein kewertjie uit teken is ongelukkig aan die skade wat reeds gedoen is. Dit lyk of die boom se stam met bokhael geskiet is.
Lees meer hieronder oor die kewer. Die artikel is op Bizcommunity geplaas:
The beetle was initially discovered in a botanical garden on the country’s east coast. It has since been detected along the southern Cape coast line as well as in several inland urban areas. The number of tree species attacked in South Africa has also risen alarmingly.
The shothole borer, which is native to Southeast Asia, has the potential to affect fruit, nut and wood production, but also to permanently change urban landscapes and natural forest ecosystems. This has happened on farms, in suburbs and in forests along river valleys in California.
The South African government has started to take steps to manage the problem. The Department of Agriculture, Fisheries and Forestry has set up a steering committee to guide national efforts. It’s made up of representatives from various government departments, the forestry and agriculture sectors, as well as academics, arborists, and nurserymen.
The major challenge with the beetle infestation is that the insect is crossing the boundaries between agriculture, commercial forestry, natural forests, and urban trees. Never in the country’s history has any insect attacked and killed trees in all these sectors. The protection of trees the different sectors is typically dealt with by different government departments, namely Department of Agriculture, Fisheries and Forestry, the Department of Environmental Affairs, and municipalities. But given the beetle’s unusual behaviour, routine action plans aren’t enough to curb the problem.
The threat to South Africa’s trees
Of the 80 species of trees under attack in South Africa, about 20 are reproductive hosts in which the beetle inoculates its fungus and then multiplies. These trees pose a serious risk to the environment around them as they become a source of infestation.
In the remaining 60 host species the beetle also inserts the fungus, but it doesn’t reproduce in them. Although some of these trees may eventually die, they don’t pose a threat to the other trees around them.
The species of ornamental and street trees most affected in South Africa’s cities are the London plane, Boxelder, Japanese maple, Chinese maple, English oak and Liquidamber. Several streets of maples and liquidamber have died in some cities, and large, old English oaks and plane trees have been severely affected in some areas.
During countrywide surveys conducted by our team at FABI, we found several fruit trees (peach, olive, grapevine, guava, fig) infested in urban areas. However, the only commercial crop that’s affected at present are pecan nut trees on farms in the Northern Cape.
In Israel and California the beetle caused substantial damage in avocado orchards, and although South African orchards are closely monitored by FABI team members, we have only detected it on a single backyard avocado tree in Johannesburg. Similarly, we found it on roadside wattle and eucalyptus trees, but so far the pest hasn’t been detected in commercial Eucalyptus, wattle or pine plantations.
In our opinion the most significant threat, but also the most difficult to predict and manage, is to South Africa’s native tree species such as coral trees, wild olives, yellow woods and Natal figs.