Question
QUESTION:
I have a variety of orchids which have thrived for years. Within the last 3 months a white fluffy fungus (?) has shown up on the leaves and is now spreading from plant to plant. How do I kill it? Thanks, Andrea

ANSWER: Hello Andrea,

White fluffy fungus on the leaves of your orchids?  While I cannot be certain, I believe what you have are mealybugs.  If you have some isopropyl alcohol and some Q-tips, dip one into the alcohol and touch the the white fluffy stuff.  The white part will disappear to expose the mealybug.  

If they are mealybugs, you definitely will want to get rid of them because left alone their population will explode and cover all your orchid leaves.  On top of that, they will be sucking the moisture right out of the leaves and slowly kill your orchids.  

You can kill the visible ones with the alcohol and Q-tips or you can use a soft paper towel dipped in alcohol and wipe the leaves being sure to get both the top and bottom of the leafs.  Unfortunately, this only gets rid of the ones you can see, leaving the ones still within the pot to come out later.  

The best method would be to unpot the orchids, thoroughly cleanse them (including the roots) of mealybugs, clean the pots then repot the orchids using fresh potting media.  

If you find that they are not mealybugs, write back and I'll explore some other possibilities.  

Jim Kawasaki
San Jose, Ca.


---------- FOLLOW-UP ----------

QUESTION:
Thanks Jim and they are squishy mealybugs. I have a follow up question...many are currently blooming or putting out bloom stalks. Would washing and re-potting them now cause the blooms to drop or should I wait until the blooms fade  to repot and treat with alcohol in the meantime? And should I use any type of cleansing solution or just water? Thank you so much, Andrea

Answer
Hi Andrea,

While it is in bloom, do the alcohol rub treatment being sure to get the underside of the leaves where they love to hide while feeding on the leaves.  

Yes, wait for the blooms to all fall off before repotting it.  I only recommend repotting a blooming orchid when the plant is in really bad condition and waiting any longer would lead to certain death of the plant.  

In the meantime, if you have a systemic insecticide that is recommended for orchids, you can use it on the phal.  Systemics do not kill insects on contact but slowly through the plant itself.  When they feed on the plant, they ingest the toxin that kills them.  It is always best to use the insecticide three times over three weeks to catch any newly hatched eggs.  

Jim Kawasaki
San Jose, Ca.