How long have these trees been in the ground? Tell us a little bit about the site: sun duration, soil type, drainage, etc.

Also, is there any way that you could let us see these trees via some good photographs?

Copper is a fungicide, and I don't know if it would work to control a pest. I wouldn't try it.

For the weevils, I would consider putting predatory nematodes into the ground under the trees. Won't help with the current generation but it should help to break the life cycle and give you long-term control. This may or may not be prohibitively expensive depending on how much ground you need to cover. I have had good results with nematodes for many types of pest that have part of their life cycle underground, everything from cutworms to fleas.

I have never had luck with Neem oil, on anything. Other people swear by it, but not I.

Aphids are rarely a problem without ants. Ants protect aphids from predation, so if you see ants amongst the aphids you may want to look into controlling those first. There is goo called Tanglefoot you can put onto the trunk of a tree to trap any ants attempting to climb it, and you should trim any branches that reach the ground so that they don't do that anymore. The aphid problem may handle itself once the ants are kept away from them, or you may want to consider a ladybird release. Ladybirds (ladybugs) are fairly cheap nowadays, and should work as long as you keep the ants away from the aphids.

I know nothing about psyllids. From the look of them, young praying manids might take them, but I don't know.

Thanks so much for your replies. I hate to post pictures because they look so horrible. All of you northern growers seem to have such beautiful green trees in pots. Maybe I need to move up north and grow in pots too! I will try to get some posted though.

The reason I use copper is because I probably have every fungus you can think of in my yard too. I have been gardening organically for about 4 years and have a lot of beneficial bugs in my yard. I guess the aphids are just more prolific than the beneficials. I live way out west of Fort Lauderdale about a 1.5 miles from the Everglades. The soil is muck soil with limestone about 1.5 feet down. Some parts where we brought in some fill around the house pad have a little sand too. Most things I plant seem to like the soil.

I also have access to horse manure which I use a lot around my fruit trees. I heard citrus doesn't like that so much and that the roots need air, so I've stopped using it on the citrus. They get sun most of the day. A few of the key limes are shaded in the morning but then get sun from about 10:30 on. I have 4 key limes, 2 in the ground and 2 in pots. One grapefruit (the one I might loose), and two tangerines (look the best). I have other trees that need spraying too. Mangoes (2 types), bananas, grumichama, sugar apple, fig, passion fruit and lychee. Of all of these, citrus are giving me the hardest time.

I do have a big problem with ants in my yard and love the tanglefoot idea. The nematodes sound great too and I have already done some research on them but can't find the one that is specifically for the diaprepes root weevil. I will continue my search. I just bought a new backpack sprayer because this spraying job is getting huge.

Terri

If you really do have canker, copper is the right material to be using there. Diaprepes are another matter -- are you sure that's what they are? About the diameter of a dime or even a nickel, with prominent length-ways stripes? There are several other similar, but smaller, unstriped weevils in S. Fla. that are FAR less damaging.

As a citrus fan, I am sorry to say it, but I think if I had canker AND diaprepes, I'd remove my trees and plant mangos. You're not likely ever to get rid of Diaprepes, once it's there, and even though many methods will reduce its population, a single fat larva can kill an adult citrus tree. No other weevil we have can do that.

With a muck soil and root weevils, you will likely have problems with Phytophthora root rot. So you are right about not using manure around them, and in general, you should keep the soil on the dry side. If you need to control Phytophthora chemically, Ridomil Gold, Subdue, or Aliette will do it, but all are fantastically expensive and not available in small quantities.

I'm sure they are diaprepes. I took an entomology class and showed them to my professor. I was kind of feeling already that I should rip them all out. Very depressing thought. I don't think I'm quite ready to give up yet. I'm finding some nematodes online that do mention the citrus root weevil and as a bonus will work on the ants too.

Terri,

I love the thought of planting Mangoes in their place..But it is sad to have to rid any plant you treasure and fight so hard to keep alive..

You live in a wonderful place for citrus, and I bet that if you ever want to grow them again, you would LOVE and have great success growing them in containers..Much easier to contain the problems they suffer with in m any ways..

Good luck..:-( :-)

Mike

Unfortunatley I have seen the root weevils on my mangoes too. I don't know if they like their roots as well, but I guess I had better look that one up too. I do have two key limes in pots and one of them is my best looking key lime. I haven't seen diaprepes on any of the key limes. Mostly on the grapefruit and my new mango with lots of new growth. I was shaking them off the tree early this summer and squashing them. They're pretty easy to catch.

Yes, weevils will get on mango, but fortunately, mango is immune to Phytophthora root rot, and it is through that disease that Diaprepes does its major damage to citrus.

Terris:

I looked through my beneficials suppliers and the only one I can find that MAY sell the recommended nematode species is Rincon-Vitova. They have both listed (Heterorhabditis indica on their website and Steinernema riobravis in their catalogue) but only have a price for S. riobravis (and only one option for that one, and it's a pricey one). I've attached a link to the catalogue, do a search within the pdf for NESR2-BU to find the listing.

Sorry to hear about the canker - I would be very sad if any tree of mine caught canker. I would also be very frustrated if my yard had as many problems as yours does, so I admire your willingness to keep fighting.

One of the few benefits to living in a climate where citrus don't naturally thrive is that there aren't a lot of other citrus trees around to harbor diseases and citrus-specific pests. Mine are probably the only ones in a 10-mile radius or more. I get generalist pests only, like spider mites and scale.

Here is a link that might be useful: R-V insectary

In case anyone else is looking for nematodes, here is the best price I have found so far. $47.50 for 50 million. This is supposed to treat 1/2 acre. I'll add the link below. I'm not sure I should use them yet because this is the time of year we could get some flooding from hurricanes and tropical storms. I know flooding kills bad nematodes, so I'm assuming it would hurt the good ones too.

It sometimes get discouraging to be fighting pests and diseases all the time, but I see lots of yards with beautiful mango and avocado trees. Maybe they aren't trying to go organic like I am. I need to join the local gardening club, we have a club for rare fruits that I'm sure could really help. I bought some of my trees from them.

Most of the posts I read on this board seem to be refering to a lot of organic controls, and that's what I like. If I can't do it organically, I will take it out and put in something I can grow organically. I just grew up with citrus trees in my yard. We had grapefruit, tangerines, ponderosa lemons and calamondins. I would love to have them again.

Here is a link that might be useful: buglogical

You said you had psyllids. That is really bad news. It has wiped out over 50% of your state's citrus industry. It is heading towards us, too.

Check out the post and video on the blog post listed below. It is about our crisis in California, but it features graphics of the destruction in Florida...

Here is a link that might be useful: Asian Citrus Psyllid

Mike, not to argue, but we've lost no where near 50% of our industry. And what we have lost has been due to greening (spread by psyllids), canker, freezes, diaprepes, etc. Psyllids themselves are relatively harmless, and are on nearly every tree in Florida, nearly always. It's the ones who are carrying the greening bacteria that do the damage, and in many areas we are lucky that that's still a very small percentage of their population.