More than 85 protea bushes in the nature reserve have fallen victim to a mysterious attacker. 

The race is on for researchers to save the protea bushes of the Melville Koppies nature reserve from being wiped out completely by an unknown, undocumented natural force.  

On Sunday, April 16, a group of 10 local volunteers and researchers from Wits and the University of Johannesburg (UJ) gathered to spray a mixture of soap, methylated spirits and cooking oil on the Koppies protea bushes to kill an unidentified insect believed to be killing the plants. The mixture was created through trial and error by the nature reserve’s conservation committee, and seems to have had positive results in recent weeks. 

According to Jessica Howard, a third-year BSc student at UJ doing research on the Koppies proteas, the 85 identified dying protea bushes all appear to suffer from the same ashy black substance on the back of the leaves and the presence of a mysterious, unknown insect. 

Because little is known about the insect, student research has focused on trying to understand and identify the suspect. “We think that it could be an unknown, under-researched or exotic psyllid (lerp), part of the Psyllidae family under the Aphidoidea superfamily,” Howard said. Similar to mosquitoes, these insects suck the life out of the host plant to survive.  

A sign of infection among a cluster of proteas at the Melville Koppies is eggs of an unknown insect on the leaves. Photo: Kimberley Kersten

Tam Scheideger, head of conservation at the Melville Koppies watched the infection rapidly spread. “In October [2022] there was one tree in a cluster that was infected and by April [2023], 25 trees in that cluster had become infected.” 

The infection is mostly affecting the north side of the park but has recently spread to the ridge and the south-facing side, threatening to infect every Protea caffra in the park. “It seems that once a protea is infected, it takes around a year for it to completely die,” said Howard. 

The start of the infection is difficult to spot. The noticeable difference between healthy plants and infected plants is the blackness on the back of the protea leaves and small, brown bumps on the leaves of the plant, in which the eggs of the insect can be found. However, once the infection takes over, the bushes turn black, shrivel up and die. These can be spotted throughout the north side of the park. 

According to the Melville Koppies website, the nature reserve is a well-used tool for teaching and learning at Wits. According to volunteers at the park, departments which utilise the Koppies include the geology department as well as the departments of archaeology and of animal plant and environmental sciences.   

Student researchers such as Howard hope that DNA from surviving plants can be used to develop a cure for the disease, but this will take time and will depend on getting to the root cause of the deaths. 

FEATURED IMAGE: A volunteer sprays an infected protea bush at the Melville Koppies with a special mix of insecticide on Sunday, April 16, 2023. Photo: Kimberley Kersten