ARMORED SCALES

These are uncommon on houseplants. Unlike soft scales, armored scales do not produce any honeydew and the protective shield is not attached to their body. If you pry up one of the scales, you will find a small soft bodied insect underneath.

The only effective method of controlling armored scale is horticultural oil. Both contact and systemic insecticides are largely ineffective at controlling them.

Non pesticide options:

  • Manual removal – When there is only a small infestation, armored scales are easily removed by rubbing or picking them off. Any disturbance of the scale can break its fragile mouthparts causing it to starve. Scales killed this way may appear the same as live scales

  • Horticultural oil – This is a mechanical pesticide. It kills scales by suffocating them and is active on both the crawler and adult stages. It requires direct contact and has no residual action.

    Horticultural oil and other oil-based pesticides can damage leaves. They can cause burning or other damage if applied when temperatures are high (80-85F or higher) or if the leaves are sensitive. Always test it on a couple leaves first before spraying a whole plant.

    Horticultural oil can also be mixed with many other pesticides to increase their effectiveness