Question
I recently repotted my orchid which is about to bloom. But I have found it covered with white fly. I removed them withcotton soaked with alcohol then rinsed. How can I prevent them or control them when they appear? Many thanks. Albert

Answer
Hi Albert,

I think you are confusing white fly with mealybug. White flies would not sit still while you wiped the leaves - they would fly off in a white cloud. Mealybugs look like small specs of cotton.

The difficulty with treating mealybugs is that there are always more to deal with than meets the eye. Young mealybugs lack the telltale cotton-like protective coating and they are skillful at hiding in nooks and crannies where leaves attach to one another.

The key to successfully eradicating these creatures is to also spray the ones that are out of sight. That means that whatever treatment you select, you must get complete coverage, to the drip point, of all leaf and stem surfaces. If you miss a few, they will live to breed another day and you will wonder where they came from.

I do not recommend any pesticides because they are all hazardous to use and not 100% effective against mealybugs.

Spray the Orchid with a solution of alcohol and water and add a squirt of liquid soap to help it spread. Be sure to spray all leaf and stem surfaces thoroughly. The common practice of applying alcohol with a Q-tip is not effective because it misses the ones you can抰 see. Wiping the leaves is a only a bit more effective. It is also best if you repeat this treatment again in 5 to 7 days to catch any crawlers that you missed the first time. After that, you should check your plant weekly to see if they return.

Never spray in direct sunlight or when temperatures are above 75 degrees. It is also advisable to test any spray on a few leaves as a test before you spray the entire plant. Wait a few days following the test to see if there is any negative reaction to the spray.

Please let me know if any of this is unclear or if you have any additional questions. If you would like to e-mail me some photos, I may be able to provide some additional insights.

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Regards,
Will Creed, Interior Landscaper
Horticultural Help, NYC

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