Question
QUESTION: I saw your answer to mealy bugs.  I was wondering if the plants seen with mealy bugs should be repotted and not just spot treated?  Are they difficult to get rid of?  And do they spread?  Thanks!

ANSWER: Sky, the answers are yes, yes, and yes.  After unpotting, remove all mealies you can see, then Soak the plant in an insecticide effective against mealy.  Repot in a clean pot and fresh orchid potting mix.  Discard the old mix and pot. If the plant was in the vicinity of other plants, they may also have mealy and could be the source of reinfestation

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QUESTION: How did the mealy bugs come about?  Is it my culture?  Thanks

Answer
That is a very good question and many orchid growers often ask. It is not likely your culture They can come in on a plant that you have acquired-- either in the adult, larva, or egg stage. They can be hidden beneath plant sheaths or in the potting mix.  Since they secrete a wax covering, they can be difficult to kill.  In severe infestations, it may take three or more weekly applications of an insecticide such as malathion.  The usual procedures are to first remove all insects with a q-tip soaked in alcohol.  Likely there will be insects you will miss this way so it is generally recommended to treat with an insecticide effective against mealy at weekly intervals to kill any newly hatching insects. I prefer to add a systemic insecticide that actually gets into the plant tissues and kills the insects as they feed. Many of these come in powder or granulated form and will be effective for 6-8 weeks. The drawback with many of these treatments is that they leave an unpleasant odor and the treatment is best done outside.