RUBBER NEWS

Insect Pests in Vietnam’s Rubber Plantations

Posted on by content02.vinahugo
13
Oct

Rubber plantations in Vietnam face various insect pest threats that attack leaves, stems, roots, and latex-producing bark. Effective monitoring and timely chemical control are essential to maintain tree health and latex yield.

1. Leaf Weevil (Hypomeces squamosus)

  • Description: A beetle species with metallic-green elytra, living in groups of 3–4 individuals under leaves. Adults feed on mature leaves, leaving only the veins, while larvae damage the roots.

  • Control:

    • Hand-pick or use a net to collect adults.

    • Apply Cypermethrin 0.02% (200 ppm) or Alpha-cypermethrin 0.02% (200 ppm) as a foliar spray.
      (See Figure IX.17)

2. Leaf-Eating Caterpillars and Loopers (Family Noctuidae & Tortricidae)

  • Damage: Feed on young shoots and tender leaves. Severe infestations cause defoliation and loss of growth vigor.

  • Control: Spray Abamectin 0.0036–0.0072% (36–72 ppm) or Cypermethrin 0.01–0.02% (100–200 ppm) when infestation is high.

3. Red and Yellow Mites

  • Occurrence: Common during the leaf-flushing season, coinciding with powdery mildew outbreaks.

  • Damage: Mites inhabit leaf undersides, causing leaf curling, asymmetry, and wrinkling — symptoms often mistaken for zinc deficiency.

  • Control: Only spray when infestation is severe using Abamectin 0.0036–0.0072% (36–72 ppm) or Cypermethrin 0.01–0.02% (100–200 ppm).

4. Bark-Eating Caterpillars

  • Species: Euproctis subnotata, Hemithe brachteigutta, Acanthopsyche snelleni.

  • Damage: Feed on primary and regenerated bark, affecting latex flow and tapping quality.

  • Control: Apply Cypermethrin 0.02% (200 ppm) only when infestation is heavy.

5. Termites (Globitermes sulphureus, Coptotermes curvignathus)

  • Damage: Build mud tunnels above the soil and feed on roots, causing tree death.
    (See Figure IX.18)

  • Preventive Measures:

    • Avoid burying fresh grass or crop residues in planting holes.

    • Keep mulching materials 10 cm away from trunks.

  • Chemical Control:

    • Drench termite mounds with Imidacloprid 0.02–0.04% (200–400 ppm) or Alpha-cypermethrin 0.01–0.02% (100–200 ppm) at 4–5 L/mound.

    • For tree protection, apply 0.5–1.0 L/tree around the base.

    • During planting:

      • For bare-root seedlings: add Imidacloprid 0.08% (800 ppm) or Alpha-cypermethrin 0.04% (400 ppm) to the root-dipping mix.

      • For potted seedlings: apply Imidacloprid 0.06–0.08% (600–800 ppm) or Alpha-cypermethrin 0.03–0.04% (300–400 ppm) at 50 ml/pot 2–3 days before planting.

6. Root Grubs (Family Melolonthidae)

  • Distribution: Found in grey sandy soils and areas using undecomposed organic manure or animal grazingzones.

  • Biology: White, C-shaped larvae (grubs) of scarab beetles feed on roots, causing wilting, uprooting, and plant death.
    (See Figure IX.19)

  • Control:

    • Prohibit cattle grazing in plantations.

    • Avoid fresh manure application.

    • Drench soil with Imidacloprid 0.03–0.05% (300–500 ppm) around tree base (200–300 ml/tree, 1–2 years old).

    • Pre-treat nursery soil before sowing rubber seeds.

    • Use light traps to capture adult beetles in high-risk areas.

7. Scale Insects & Mealybugs (Pinnaspis aspidistrae, Saissetia nigra, S. oleae, Lepidosaphes cocculi)

  • Damage: Sap-sucking pests on leaves, shoots, and branches of 1–4-year-old trees, causing leaf drop, stunted growth, and dieback.

  • Also infest cover crops and intercrops.
    (See Figure IX.20)

  • Control: Spray Abamectin 0.0036–0.0072% (36–72 ppm) or Imidacloprid 0.01–0.02% (100–200 ppm) on affected parts, 2–3 applications every 7–10 days.

8. Black Beetles (Mesomorphus villiger)

  • Nature: Non-destructive but become nuisance pests when crowding the tapping panels, obstructing latex flow and contaminating cups.

  • Control: Apply Cypermethrin or Alpha-cypermethrin 0.02–0.03% (200–300 ppm) only during heavy infestations.

9. Lady Beetles (Epilachna indica, Harmonia axyridis)

  • Behavior: Larvae emerge during leaf-flushing season, feeding on young leaf tissues, causing yellowing and deformation.

  • Host Range: Also attack intercrops and ground covers.

  • Control: Spray Cypermethrin or Alpha-cypermethrin 0.02–0.03% (200–300 ppm) when infestation is severe.

Conclusion

Vietnam’s rubber plantations host a diverse group of insect pests, many of which thrive in specific climates or growth stages.
An integrated pest management (IPM) approach — combining regular field scouting, biological control, and rational pesticide use — helps maintain sustainability and minimize environmental impact.