1. Integrated control of macadamia
pests in South Africa with specific
emphasis on stink bugs
Schalk Schoeman

2. Introduction
• Understand the problem
• Difficult to monitor for the stinkbugs (no
pheromones!!)
• Low tolerance for damage
• Bugs migrate between various crops as well as wild
hosts
• Most chemicals really only work for a few days
• Integrate/coordinate control between a number of
crops.
• Website regarding macadamia monitoring a beginning
but more is needed

3. Materials and methods
• Monitoring with branch shaking method since
the spring of 2010
• Nut dissection during the early part of the
season
• Pheromones for the tortricid complex
• Quantification of eggs, larvae as well as
damage up to physiological maturity
• Two localities – unsprayed mixed cultivar
orchards

4. Relative seasonal abundance -
Nelspruit
40
35
Total number of stinkbugs/10 trees
30
25
20
15
10
5
0
n d j j f mm a a mm j j j j a s s o o n n d d j j f f mm a a m
2010 2011 2012

5. Relative seasonal abundance - Friedenheim
2011 2012

6. Overwintering/diapause of the two
spotted bug - Nelspruit
2010

7. Overwintering/diapause of the two
spotted bug - Friedenheim

8. Seasonal succession of indigenous
stinkbugs at Nelspruit
120
100
80
Percentage
60
40
20
0
n d j j f mm a a mm j j j j a s s o o n n d d j j f f mm a a mm j j j j
2010 Two spotted bug Other pentatomid bugs 2012

9. Seasonal succession of indigenous
stinkbugs at Friedenheim
120
100
80
Percentage
60
40
20
0
o o n n n n d d d j j j j f f f f f mmmm a a a mmmmm j j j j j j a
Weeks
2011 Two spotted bug Other pentatomid bugs
2012

10. Relative seasonal abundance of the
coconut bug
2011 2012

11. 80
Host switching behaviour
70
Number of damaged fruit/5 trees
60
50
40
30
20
10
0
o o n n n n n d d d d j j j j j f f f f m m m m
Litchis

12. 80
Host switching behaviour
70
Number of damaged fruit/5 trees
60
50
40
30
20
10
0
o o n n n n n d d d d j j j j j f f f f m m m m
Macadamia Litchis

13. 140
Host switching behaviour
120
Number of damaged fruit/5 trees
100
80
60
40
20
0
o o n n n n n d d d d j j j j j f f f f m m m m
Avocado Macadamia Litchis

14. Summary of insect ecology in the
orchard

15. Summary of insect ecology in the
orchard

16. Summary of insect ecology in the
orchard

17. Summary of insect ecology in the
orchard

18. Summary of insect ecology in the
orchard

19. Summary of insect ecology in the
orchard

20. Summary of insect ecology in the
orchard

21. Summary of insect ecology in the
orchard

22. Summary of insect ecology in the
orchard

23. Summary of insect ecology in the
orchard

24. Proposed spraying dates

25. Proposed spraying dates

26. Proposed spraying dates

27. Proposed spraying dates

28. Proposed spraying dates

29. Relative abundance of nut borers and
related damage

30. Relationship between pheromone trap
catches and various nut borer stages
Regression coefficient (r2)
Eggs Larvae Damage
Eggs
Larvae 0.372
Nelspruit
Damage 0.864 0.399
Moths 0.588 0.277 0.47
Eggs
Larvae -0.453
Damage 0.676 -0.421
Friedenheim
Moths -0.641 0.451 -0.488

31. Relative seasonal abundance of nut borer moths
in relation to damage - Nelspruit

32. Relative seasonal abundance of nut borer moths
in relation to damage - Friedenheim

33. Conclusions
• Summer peak of two spotted bug ± 1220 degree days
• Autumn peak of two spotted bug ± 2220 less well defined
• Coconut bug is important !! – check for fallen nuts during December
• Two spotted bug overwinter as adults and nymphs
• Very low population levels during early summer – only adults
• Other bugs migrate into macadamia orchards during winter but don’t
breed.
• Moths migrate into mac orchards ± 9 weeks after full bloom.
• Mating and oviposition takes place soon afterwards
• Best time for spraying a contact insecticide - ± 2 weeks after peak moth
flights are recorded during Nov/Dec
• Scouting for both complexes will be available on a website before the new
season.
• Website will be updated weekly
• Initially Nelspruit area but Levubu and KZN will be added through the
season

34. Acknowledgements
• Subtrop
• Members of the stink bug working group and
particularly Gerhard Nortje
• ARC-ITSC
• Colleen Hepburn
• Prof. Ben Botha