What's eating my rough-shelled macadamia?

Rough-Shelled Macadamia (Macadamia tetraphylla) faces similar pest pressures to M. integrifolia but its rougher, thicker shell gives the nut borer slightly more difficulty. Scale insects, macadamia nut borer, and stink bugs are the main threats. Rats are a significant problem in subtropical growing areas. Management mirrors that used for M. integrifolia.

Cottony white masses on shoots and leaf undersides; sooty mold from honeydew; shoot dieback under heavy infestation Horticultural oil sprays targeting crawler stage; preserve Coccophagus parasitoid wasps; prune out heavily infested wood

Larvae tunnel into developing nuts, causing premature nut drop with visible entry holes Sanitation — collect and destroy fallen nuts; pheromone traps; spinosad spray timed to moth flight; reduce alternate host plants nearby

Gum spots and internal browning of kernels from piercing feeding on immature nuts Monitor with lure traps; pyrethrin at threshold; manage border vegetation; biological control via Trissolcus egg parasitoids