A recent article in The Conversation, gave a good summary of the state of affairs, and also asks some good questions!
“More than two years have passed since the detection of what is arguably the most damaging tree pest ever to arrive in South Africa: the polyphagous shot hole borer (Euwallacea fornicatus). The beetle kills trees and there are no proven remedies.
The beetle is now present in nearly all parts of the country and in more than 100 tree species.”
Read more at https://theconversation.com/trees-in-south-africa-are-under-attack-why-its-proving-hard-to-manage-130804 and think – should we begin to be concerned.