How to recognize Hydrangea scale

Young stages of Hydrangea scale are light brown and flat. Adult stages are round and more swollen. From June and July remarkable white egg sacs become visible. There is only one generation per year in which a single female can produce up to 1000 new scales. Depending on the season, young stages can be found on the leaf, petiole or branch. Adult stages are usually found on the underside of the leaves.

Hydrangea scale damage

Damage by the Hydrangea scale ismainly cosmetic. During heavy infestations, large amounts of honeydew are produced. The honeydew acts as a growth medium for black sooty mold fungus which will turn the leaves black. Thiscan hamper photosynthesis.

  • Life cycle Hydrangea scale

    1000 eggs per female
    young stages light brown, adult stages rounded
    from June and July egg masses visible
    young stages on leaf, petiole or branch
    adult stages on underside of leaf

  • Host plants Hydrangea scale

    linden, Platanus

  • Hydrangea dopluis close up

  • Hydrangea scale on Hortensia