Any good suggestion for spray for whitefly control after Marathon is applied and a few hot spots of whiteflies are noticed, after bracts are starting to color.

My suggestion would be a spray of either Avid or Sanmite and then 7-14 days later apply the other. Judo is also very good but a little more costly compared to Avid and Sanmite. You will not see a lot of dead adults the next day with these chemicals. However, the number adults should drop rapidly after 2-3 days. Over a week or so a few new adults will emerge but they should be controlled by residues on the plant or with the second spray. http://mrec.ifas.ufl.edu/LSO/DOCUMENTS/Whitefly%20Manag...0Program-3-26-06.pdf is good info on activity of different chemicals. Note that this work was directed at the Q type which is more difficult to control but less common than the B type. However, Q is not controlled as well by Marathon as is the B, so if you have whitefly coming back now (I feel) it is best to treat them like they are Q and be more aggressive with the control. The advantage of the chemicals above is that they work in different ways. TriStar and Safari are both very good as sprays for both B and Q, but because they have same mode of action (IRAC class) as Marathon it is recommended that they not be used following Marathon to help avoid developing resistance. Jim

Consider Mycotrol, I have used it for aphids and found it very effective. According to trials I have seen it works very well against the Q biotype. Also, no surfactants are needed. (Use Mycotrol, not Botanigard as Botanigard can have phyotoxic effects on bracts showing color). (For more info www.bioworksinc.com)
Doug

For information above this link works http://www.bioworksinc.com

Jim,
Thanks for correcting the link.
Doug