Thanks for all the ideas guys, just brought some flytraps and sundews in and saw whitefly flitting about. I've already got the othene so they should be dead by morning and the newly hatched ones in another week or so.

As far as toxicity orthene is relatively benign as stated, I once saw an old guy I worked for stick his hand in a tank of lanate to retrieve something, my jaw dropped. The LD 50 is 2 for oral and in the 1000's for dermal but why !! He is a still alive and a long story for another day.