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lanette1982

Strange damage on leaves of rhododendron

Lanette1982
9 years ago

We bought 3 PJM rhodies in May 2014. We planted them. Recently, we noticed strange damage on leaves (please, see photos). I contacted 2 different State entomologists but they were UNABLE to identify insect and damage. State pathologist e-mailed me that it looks like sap sacking insect. However, she does not know the name of insect. I went back to the store (where I bought rhodies), found identical damage on rhodies and blueberries in their Garden Center, and talked to a manager and Seller in Garden Center. Manager could not identify insect as well. I also found small round dark yellow colored "balls/eggs" in a pot with a blueberry in garden center. Those "eggs/balls" were easy to destroy, and they appeared to be liquid (not powder substance like majority of fertilizers). What sap sucking insect could destroy leaves in such way?

Comments (9)

  • Lanette1982
    Original Author
    9 years ago

    more photos

  • Lanette1982
    Original Author
    9 years ago

    more photos; this photo of Purple Gem rhody. Leaves look like damaged by lace bug and maybe black vine weevil but I am not sure

  • morz8 - Washington Coast
    9 years ago

    That isn't lace bug damage and it's not weevil either. I suspect mechanical damage that occurred either in the garden center or transportation to and from there and not an insect at all.

    As for the round pellets you found in another pot at your supplier, some kind of fertilizer product is still a likely guess.

  • Lanette1982
    Original Author
    9 years ago

    Well, there was NO mechanical damage, and we do NOT leave in urban area. I am picky when I buy my plants. I watch my plants. I quarantined 2 rhodies, and I used insecticide. it helped a little bit. However, new deformed leaves appear from time to time. I know that Asiatic garden beetle may cause damage which is similar to damage on a leaf (see second picture).

  • Lanette1982
    Original Author
    9 years ago

    Here is photo of "eggs/balls".

  • Lanette1982
    Original Author
    9 years ago

    more photos. I wish, manufacture produce fertilizer in any color for the except earthy tones, black, and white. Sometimes, fertilizer looks very similar to eggs of insect.

  • akamainegrower
    9 years ago

    Morz8 is correct in that this looks nothing like either weevil or lacebug damage. Mechanical damage during transportaton to the garden center or an unknown sap sucking insect are realistic possibilities. The original damage would have been very hard to detect but was sufficient to cause the leaf distortion and the death of some leaf tissue. The latter is what led to the brown discoloration now very visible. What percentage of the leaves show damage? If it's relatively minor, it may be that this particular variety produces a percentage of deformed leaves and no pest or damage is involved.

    The "eggs" are almost certainly controlled release fertilzer prills.

  • Lanette1982
    Original Author
    9 years ago

    It is relatively minor. However, new damage appears because I watch my plants. The plants were small when I bought them from retail store. I bought them in 1/4 container. There were NO mechanical damage during transportation. I did research, and I know that leaves can be deformed if roots were eaten by larvae or grubs. Brown discoloration is caused by sap sucking insect because I used insecticide on leaves and it helped a little bit (less damaged leaves on two shrubs). Probably, "eggs" is slow release fertilizer because these eggs are scattered around the pot and in a bag of Miracle Grow Garden soil. Anyway, I will solve problem by contacting entomologist or plant pathologist.

  • mikebotann
    9 years ago

    The minor damage to your leaves may be caused by thrips. They feed on the newly opening leaves when they are very tender, resulting on the damage you see after they have opened. Thrips feed on blossoms also.
    Those 'eggs' you see are no doubt Osmocote prills, a fertilizer used throughout the nursery industry.
    Mike

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