Prof Wilhelm de Beer of FABI addresses workshop participants.

A team of scientists from FABI under the leadership of Prof. Wilhelm de Beer hosted the first workshop in Africa focused on the invasion of the Polyphagous Shot Hole Borer (PSHB).

This was in response to a request by the Centre for Agriculture and Bioscience International to train scientists from across Africa to enable them to detect the presence of the PSHB elsewhere in Africa.

The PSHB was first reported from South Africa early in 2018 after it was discovered infesting trees in KwaZulu-Natal. However, it has not been reported from elsewhere in Africa, although there is a strong possibility that this Southeast Asian pest is already present in other African countries.

The beetle carries a fungus that infects and can kill trees, depending on the species. The beetle and fungus have been responsible for the death of thousands of street trees in Johannesburg, Pietermaritzburg, George and Knysna. It also has the potential to cause severe damage to commercial tree crops such as avocado and pecans.

Urban tree showing damage form the shothole borer and fungus.

As the invasive PSHB can easily be confused with other common ambrosia beetles, it may not be detected, hence the request from CABI for FABI to train scientists of African countries to recognise the beetle and its fungus, before an invasion reaches epidemic proportions. This would enable the implementation of management strategies to mitigate its impact.

The workshop was attended by 25 people from 14 countries that included Botswana, Cameroon, Ethiopia, Ghana, Kenya, Malawi, Mozambique, Namibia, South Africa, Swaziland, Tanzania, Uganda, Zambia and Zimbabwe. Lectures were presented by various members of the FABI team, the ARC and the Early Warning Systems division of DAFF, on aspects like the biology, life cycle, symbiosis, impact, spread, control and management of the PSHB.

The group also visited streets with infested trees in Johannesburg where City Parks staff felled heavily infested trees to show how reproductive hosts trees can be recognized.

The participants at the workshop have now formed a PSHB African network under the guidance of Dr Arne Witt of CABI, that will monitor and report possible PSHB infestations in Africa.

The FABI diagnostic clinic, managed by Darryl Herron, is currently the only facility in the country that can reliably identify both the beetle and its fungal symbionts based on state-of-the-art molecular techniques.

Workshop participants visit the FABI lab.

A PSHB research team has been established at FABI. Projects range from pecan and avocado trees, to urban and native forests. Funding has already been secured from the pecan, avocado and forestry industries, and negotiations for further funding and specific projects are underway with Johannesburg City Parks, SANBI, DEA, and DAFF.

The FABI team will collaborate widely with other institutions like the Universities of Stellenbosch, Rhodes, and the Witwatersrand, as well as DAFF, DEA, the ARC, SANBI, SANParks, Ezemvelo KZN Wildlife, and various municipalities. The overall aim is to establish a reliable countrywide monitoring platform, and acquire scientifically sound data that will inform realistic treatment and management options.

For more info, visit:
www.fabinet.up.ac.za/index.php/research/7