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Scale insects on pineapple are dominated by Diaspis bromeliae (pineapple scale). Small (1 to 2 mm) tan or brown scales attach to lower leaf undersides and the leaf axil, feed on sap, and reduce plant vigor. Scale is less damaging than mealybugs but can be economically significant on export-quality blocks and where cosmetic fruit quality matters. Regional priority: Moderate everywhere; higher on export-quality MD2 and Josapine blocks.

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When pineapple is most vulnerable

At late vegetative to fruit development. Scale populations grow slowly and become visible from month 8 to 10 onward.

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How scale shows in satellite data

  • Not detectable at Sentinel scale.
  • Heavy infestation causes block-wide slight NDVI shortfall but is easily mistaken for chronic nutrient or nematode issues.

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Field symptoms

  • Small tan or brown bumps (1 to 2 mm) on lower leaf undersides
  • Grayish-white encrustation on the leaf axil in heavy infestation
  • Yellowing of infested leaves, starting under the scale colonies
  • Sticky honeydew and sooty mold below infested plants (though less than mealybugs)
  • Ants sometimes tend scale, similar to mealybugs
  • Fruit skin scarring when scale colonizes developing fruit

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Reduce the damage by

  • Buprofezin (IGR) or spirotetramat (systemic) - the two best-fit chemistries for scale on pineapple.
  • Preventive spray on high-value blocks 2 months before harvest to keep fruit cosmetics clean.
  • Conserve predators and parasitoids - avoid broad-spectrum sprays that kill scale-feeding lady beetles and parasitoid wasps.
  • Ant control where scale is being tended - baits break the ant-scale association.
  • Clean planting material - scale rides on suckers between blocks.
  • Threshold - action at more than 10 scales per D-leaf during fruit development, or any scale on developing fruit.

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Set an alert for early warning

Turn the diagnosis into a trigger. Scale is a slow build-up pest, so schedule scouting and pre-harvest walks.
Recommended settings for scale on pineapple:
  • Monthly scouting reminder - schedule scale-focused walks monthly from month 8 onward.
  • Pre-harvest fruit-quality alert - flag any block with scale on developing fruit 8 weeks before harvest.
  • Post-insecticide alert - schedule a scale scout 4 weeks after any broad-spectrum insecticide (secondary outbreaks).