Using Bats And Birds To Control Macadamia Crop Pests

Biological pest control could speed up the farm-to-fork process and save the macadamia industry millions of rands, according to the initial results of an ongoing research project. The researchers have found that bats and birds can keep the crop’s most significant pests, stinkbugs, under control.

- Siyanda Sishuba

Stinkbugs are a major challenge for the South African macadamia industry. According to Prof Peter Taylor of the South African Research Chairs Initiative (SARChI), the damage caused by stinkbugs to macadamia orchards in the country is estimated to be between R50 million and R100 million per year. But recent research findings show that natural pest control using bats could save the South African macadamia nut industry millions of rands.

Green Farms Nut Company (GFNC), four GFNC suppliers, the SA Macadamia Growers’ Association, SARChI and the University of Venda have set up a collaborative research project using bats and birds to control pests. The research is taking place on six farms in the Levubu, Thoyandou and Louis Trichardt areas. Taylor is managing the two-season project, and results from the first year, which cover the 2016 and 2017 macadamia growing seasons, provide clear evidence that crop damage is increased when bats and birds are excluded from orchards. Taylor explains that economic models of the ‘avoided costs’ of bat predation on stinkbugs on and around macadamia nut trees suggest that the current level of stinkbug damage would double if bat populations in orchards were to disappear.

Any efforts to retain bat populations, through using safe pesticides or retaining natural vegetation corridors and bat houses, should therefore be strongly encouraged, he stresses.