Stubborn Whiteflies

I have had minor problems with whiteflies in the past, but this summer has been really bad.

What seems strange to me is the plants that are infested are all outside. Mainly Plumeria's and Red Leaf Hibiscus.

I have kept them under control with Neem Oil in the GH and that has worked fairly well. But now that summer is here and the plants are outside it seems to have little effect at all. I have sprayed on a 6-7 day cycle and it seems to help, but within a few days that are just as bad as ever.

I had purchased a product online called Talstar. The active ingredient is Bifenthrin. (7.9%) It has not worked either.

Any suggestions would be greatly appreciated.

Thanks,
Nautical

I've seen people say that worm castings will repel them--try top dressing your containers with the worm castings and see if that helps. It won't work instantly though, I think the worm castings have something in them that the plant takes up through its roots and it makes the plant taste bad or something, so it'll probably take a little time before you see an effect.

nautical-Talstar is a great 'contact' insecticide, but thats all that it is. It won't kill any stage but the adult stage.
If you look at the very bottom leaves of the hibiscus, you should see where the eggs are, and if you remove those leaves and keep spraying with the Neem, that should help alot. I would also take a look at the underneaths of the bottom plumeria leaves and see if you see the eggs. They are small and whitish

It also helps to spray in the early am when the whiteflies are not moving around.

E-crane, thanks for the advice. I have to admit I have no idea what worm castings are, or where I would get them.

Tiger, thanks for the info on the Talstar. Can you advise me as to how I should best use this product? And what I should use it on? The rep at the company adivsed this was a good product for most GH pests, also suggested it was a good perimeter spray for common ants, etc. If it is contact only, then I am assuming that is a waste of time. I chose this product as I have to small Yorkies and it is suppose to be fairly pet friendly. I never let the pups out after I have sprayed anything until I know everything is dry.

I did look at the Red Leaf Hibiscus as you suggested. This is a picture, (sorry so fuzzy) of one of the lower leaves. It has one fly on it, and I am assuming those white specs are the eggs.

I am going to remove the bottom third of all the leaves from the hibiscus, and many of the lower ones on the Plumerias, then spray with Neem. Should I increase the spraying cycle to every 4 or 5 days?

It has also been suggested that I try spraying with a baby shampoo mixture, 1-2 Tbls/gal.

Thanks again for your help.

Nautical

I have had some luck spraying with neem alternating with insecticidal soap at 5-7 day intervals. This kept them in check when I was raising vegetable seedlings in the greenhouse earlier this year. The baby shampoo mixture may be similar to IS. Good luck. Becky

nautical, I would use Talstar to get instant control of a pest-like if the whiteflies were so bad-this would slow down the population alot and fast, then you could do the other things-like remove any lower leaves with eggs on them, repeat spray etc. Or one time I had a bunch of pansy worms on the pansy seedlings and they were destroying the small seedlings-Talstar took care of them and they dont lay eggs so it was a one time spray.

Yes-just above and to the left of the adult whitefly is where I see the eggs-around that vein. Just look at any of the leaves and remove any that look like that. Sometimes its just a few eggs so you have to look carefully. There are other systemics that work with whiteflies that I use, also one that sterilizes the males to stop the population-but they are pretty expensive and it would take you forever to use it up.
Removing the leaves will make a big difference.

The shampoo is used as a surfactant, I believe. Something that, when added to the Talstar, will help the Talstar adhere longer to the leaves. I generally dont use surfactants on contact insecticides for obvious reasons. Just don't water the leaves for a day after you spray Talstar, and alwasy spray in the am or pm

I can't remember the life cycle exactly of the whitefly ( I actually didn't have to deal with this past winter! what a gift that was....lol), but spray one day earlier than what it is and you will be ok.

I started removing some leaves and realized that this better represents what the eggs look like.

Thanks for all the info, I already feel better, I was getting depressed that I could not whip these things

Nautical

yeah-you can kick their butts-you just have to remove those leaves-thats a big step. Look at all those eggs that won't hatch now! Don't be scared to remove all the ones that have eggs, you will not affect the plant. If a plant has a healthy root system-they will grow back the leaves. Just start at the very bottom, and you may have to go halfway up to get all the leaves.

My first year with my greenhouse, so may be beginners luck. I'm just now starting to see a few white flies. I used neen oil and yellow sticky tape early on, and then switched over to ladybugs as there was enough meat to support them. Has worked out great! of course, I still keep everything indoors here in the Rockies, so really a different environment then your place. I just love my GH! The wife and I spend many hours in there.

Good luck, and thanks for all your help in the past.

I too have had problems with white flies in my greenhouse. I found that certain plants made the problem much worse. I no longer grow cucumbers, peppers and some flowers. I also heard that certain types of plants help repel these pests. Talon and sevin have not worked for me.