>> we have had white fly problems the last 2 years.
I think the above suggestions are right on: insecticidal soap spray, Neem and sticky traps will reduce their numbers. I think the soap spray can be repeated frequently.
Extreme cleanliness MAY reduce the problem a little. Removing damaged plants or leaves ASAP might reduce their numbers slightly. Since whitefly eggs hatch, dead leaves and soil should be cleaned up quickly.
I hope the students are old enough to appreciate how realistic the lesson is!
About three days after you figure out how to get seedlings to sprout, you start wondering how to get rid of the ##^#*##^### pests!
And how tempting it is to go in with the nuclear pesticide option and poison everything in sight.
And how non-toxic methods like "Integrated Pest Management" CAN be used ... with more effort and more smarts and constant vigilance ... and slower results. But less poison.
