South Africa’s macadamia industry has built a reputation for producing some of the finest nuts in the world. Yet every season, growers face a relentless challenge that can quietly erode profitability long before harvest begins: stink bugs. Among the complex of species found in orchards, the two-spotted stink bug (Bathycoelia distincta) and coconut bug (Pseudotheraptus wayi) remain two of the most economically important pests confronting growers today.
A healthy orchard, excellent flowering and strong nut set mean very little if stink bug damage is allowed to gain momentum. Growers are increasingly recognising that modern pest management is not about reacting to damage; it is about staying one step ahead.
Relentless Challenges Require New Approaches
Research conducted by Dr Schalk Schoeman demonstrated that stink bug activity is concentrated in the upper canopy. In the case of the coconut bug, feeding damage was found to be significantly higher in nuts collected from the top third of trees compared with nuts from the lower third.
Many orchards produce a large percentage of their crop in the upper 30% of the canopy due to improved light penetration. Coincidentally, this is exactly where stink bugs prefer to feed.
For years, many growers have relied heavily on soil-applied systemic insecticides and foliar applied contact insecticides as part of their stink bug management programmes. While these products remain important, they depend on uptake through the roots and subsequent movement through the tree before the active ingredient reaches the canopy. This process takes time. Stink bugs, however, do not wait.
This is where the foliar-applied Macadamia Combo Pack, combining Samurai® 20 SC plus Sumi-Alpha® 200 EW, offers growers a practical advantage.
Developed by Sumitomo Chemicals and marketed by Philagro South Africa, Samurai® 20 SC contains clothianidin, a systemic neonicotinoid insecticide with translaminar and plant-mobile properties. When applied to the foliage, the active ingredient is placed directly where stink bugs live and feed, allowing the product to begin working in the canopy immediately.
The Power of a Proven Combination
The Macadamia Combo Pack contains Samurai® 20 SC that is registered at a rate of 5ml/100L water in a tank mixture with Sumi-Alpha® 200 EW at a rate of only 2ml/100L water, potentially making it very affordable compared to alternatives. This combination has a pre-harvest witholding period of only 56 days!
The combination brings together two complementary modes of activity: Samurai® 20 SC (clothianidin) provides systemic activity within the plant while Sumi-Alpha® 200 EW (esfenvalerate) provides contact activity and rapid knockdown of exposed insects.
Even though application timing is largely determined by scouting reports, spraying commonly commences in November and December, or December and January. It is registered to be applied twice consecutively, four weeks apart.
Stewardship Matters
Clothianidin and esfenvalerate are both toxic to honeybees. Applications should therefore be made only after flowering, when bees are no longer active in orchards and flowering weeds are absent. Growers should also adhere to the CropLife South Africa Pollinator Stewardship Programme and all label recommendations.
The Macadamia Combo Pack gives growers a new approach for managing stinkbug pressure.
For more information, visit Philagro.co.za.
Read the label before use
SAMURAI® 20 SC | Reg. No. L10384, Act No. 36 of 1947 | Clothianidin (Neonicotinoid) (200g/L) | DANGER | Suspected of damaging fertility and the unborn child. | Causes damage to organs (central nervous system). | Very toxic to aquatic life with long-lasting effects.
SUMI-ALPHA® 200 EW | Reg. No. L8821, Act No. 36 of 1947 | Esfenvalerate (Pyrethroid) (200g/L) | DANGER | Combustible liquid. | Harmful if swallowed or inhaled. | Causes skin irritation, serious eye irritation and/or damage to organs. | May cause allergic skin reaction. | Very toxic to aquatic life with long-lasting effects.
