Snapdragon Pest Identification

Discussion in 'Outdoor Gardening in the Pacific Northwest' started by keksama, Jul 2, 2021.

  1. keksama

    keksama Member

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    Hi, post-heatwave I noticed leaves of our bee balm and snapdragons were translucent. It could be sun/heat damage, but upon closer inspection, there were 2 pests. One's maybe moth/caterpillar larvae? (They move fast.) The other is like a fine black dust... similar to snapdragon/poppy seeds, but finer. Can anyone help? Thanks!
     

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  2. Daniel Mosquin

    Daniel Mosquin Paragon of Plants UBC Botanical Garden Forums Administrator Forums Moderator 10 Years

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    The "black dust" is actually the caterpillar-processed parts of the leaves. Frass is the polite term.

    As for the caterpillars, they'll be more identifiable in later stages (well, to me, anyway). They go through a number of moults as they grow, with the final one or two moults typically the most colourful (and thus helping to identify). Look into Bt as a relatively safe way to control them if that's your goal: Bacillus thuringiensis - Canada.ca
     
  3. keksama

    keksama Member

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    That's incredibly helpful, thank you Daniel! New curse word too. ;)
     
    Georgia Strait likes this.

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