Several years ago I read this in an article by the estimable Dr. Casey Sclar, formerly Plant Health Care Leader at Longwood Gardens and now with APGA, in the April 2008 Greenhouse Product News (see references), reporting on some of his research (my highlights):
“We found that female [citrus] mealybugs lived on watered pot sections without a host plant for an average of 10 to 19 days, with crawlers still being produced up to 45 days afterwards. They live on containers, walls and benches. The day we saw hatched crawlers on stainless steel flashing, we gained a new respect for them. As part of this study, we witnessed no difference in mealybug egg mass survival on recycled fiber pots as opposed to plastic or clay containers.”
by Dan Gilrein - email@example.com
That got me focusing on the importance of sanitation – and not just the plants – where mealybugs are concerned. Based upon this we were able to solve a mealybug problem completely in one operation by consistently power-washing the benches between crops and placing new crops only on clean benches.
This past week I was called to a case of mealybugs becoming increasingly noticeable and unwelcome. The greenhouse grows valuable plants, some of which mature over a long period (many months to years)– a favorable situation for mealybugs and other pests. New material is introduced periodically, including mature specimens adding to the risk of reintroduction. With spring on the way frustration was growing along with the crop.