[hubballi]

As it is a well known fact that white fly and the like get repelled by basil, how come they are all over my basil plant ?

[Yorkie]

That's clearly the ignoramus, illiterate type of white fly you've got there then 

[mumofstig]

As it is a well known fact that white fly and the like get repelled by basil, how come they are all over my basil plant ?

Dunno about that mate if you google whitefly and basil you will find everybody gets it on theirs. I plant mine mixed with tagetes marigolds and that does seem to stop the fly getting on the basil and the toms that share the g/house border

[sunshineband]

You could try yellow sticky traps if they are in the greenhouse