Dr Elsje Joubert, entomologist and macadamia farmer from the Levubu Centre of Excellence, explains that stinkbug damage represents the biggest loss factor in macadamia production.

See PODCAST below

Joubert was speaking during the Macadamia South Africa’s (SAMAC) NPC webinar on 1 September last year. 

She shared that the macadamia industry is growing fast, which means that there are more hectares planted. There’s also more hectares of the same thing which is called a monoculture.

Joubert says monoculture means that there is more food available for stinkbugs which can lead to higher disease and pest pressure in an area.

“The common problem that we are facing in the macadamia industry is that we are not calculating our losses accurately. When you have an accurate estimate of the stinkbug damage then you make different decisions,” explains Joubert.  

Furthermore, according to Dr Elrea Strydom from SAMAC, from 2013 to 2019 early stinkbug damage was present in 1.04% of nut-in-shell, and 0.78% of nuts displayed late stinkbug damage.

The financial loss associated with stinkbug damage was R 181 000 000 in 2019 alone, “highlighting the importance of continued research on its biology and ecology in order to implement management strategies to limit these losses.”

It should also be noted that the two-spotted stinkbug is the most dominant and damaging stinkbug species in South African orchards.

Joubert goes on to explain that farmers should be aware that one gets early as well as late stinkbug damage. Early stinkbug damage refers to damage that occurred long ago when the oil content of the macadamia was lower. Late stinkbug damage, on the other hand, is damage that happened more recently or when the oil content of the macadamia was higher.  

She advises farmers that when trying to control stinkbugs in orchards, an integrated approach is needed.

“When you apply something you would have to know that in your application of a controlled programme, you have to bear in mind that this system is a whole integrated system that contributes to insect pressure due to your soil health, tree health and the disease and the pest pressure,” says Joubert.

She further advises farmers to, amongst others, change their control strategy, identify the source of infestation and scout continuously, to prune trees and to use spray rigs that can hit the target. 

Watch the full video here. 

Visit SAMAC’s website for more information. 

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