Thrips in mature ficus nitida

[mikewhite85]

Looked at a ficus today. It had a minimal amount of curling leaves with the dark waste material thrips leave. For that I plan on spraying the trunk with some safari insecticide- the stuff costs 400 bucks for a 3lb container- wowsers! A foliar spray wouldn't work due to the size of the tree but of course there are those mauget micro injections as well. I think the safari is best and fast acting but do you guys have any other ideas? I would probably have to charge around 200 for the 5min since the material is so expensive. At least I will have a lot left over for future sprayings. I hear it works great for bark beetles and other pests.

There also seems to be something else going on. Can you help me figure out what it is? The tree has begun to defoliate the weather has been up and down lately but I think it is more than just the weather. Here are a few pics of the some leaves that were on the ground. I'll also include one of leaves infected by thrips- if you look closely you can even see one of the little buggers!

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[mikewhite85]

View attachment 223706

another shot

 

[jefflovstrom]

Looks like a lot going on there. Probably a series of event's over time. Looks like a Ficus nitada. Probably has been topped for years.
Jeff

 

[mikewhite85]

It probably has been overpruned for years as it has a lot of sucker growth on the lower branches. I looked through Diseases of Trees and Shrubs and couldn't quite place what was going on aside from the thrips. I have ruled out sooty canker which is pretty common out here nor is it any kind of root rot. Some of those leaves almost look like they have a bacterial blight (just some of the ones I found on the ground. I didn't really see any in the tree). There does appear to be a dark mildew perhaps on some of the leaves, of which I am uncertain. Perhaps apply some fungicide? Maybe those microinjections as I do not have the ability to spray a tree that large.

Ultimately, I need to know the cause of the defoliation. It might just be the weather but it seems unusual how much material has come down. The branches themselves seem pretty healthy as I did not see any dead wood in the tree.

 

[beastmaster]

thrips are rarely fatal to a tree i think, ugly yes. The bad thing about spraying is you kill off the natural predators that feed on the thrips.
I am no expert but I hear its hard to spray them anyway because their rolled up in the leaves and there eggs in the leaves. I hear a light spraying of neet oil is said to be effective. I doesn't kill them but they won't lay eggs on the oily surface. I it needs to be sprayed every several weeks for a whole cycle.
It's a pain no matter what method you use because of the size of the tree.

http://entnemdept.ufl.edu/creatures/orn/thrips/cuban_laurel_thrips.htm
some good info and ideas for control. Says the purple on the leaves is caused by the thrip

 

[PremiereTreeNet]

I know this sounds kind of unlikely, but it could be Anthracnose or some other type of fungus. The bronze color of some of your leaves makes me think that it might be afflicted with something fungal. Try some benlate.

For your thrips, you can apply some nematodes, which eat thrips. The nematodes by themselves likely won't fight off your thrips, but they will help your situation.

 

[jefflovstrom]

I wouldn't suggest applying anything if you have not been there and using a guess. I would do a soil test and go from there.
Jeff

 

[ROPECLIMBER]

I agree with Jeff, the tree is surrounded by lime stone base, drive,house slab, side walk,stone facia,street curb,and masonry brick fence post.
If the tree had been topped in the past the absorption roots probbably died back to where it was topped,that combined with heavy leaching from heavy rains would cause the tree to decline from chlorosis, leaving it vulnerable to pest and fungi,
test the soil and roots first, may be able to do a drill and plug Iorn sul and compost to break down the alkilie in the existing soil and free up the usable nutrients, but like Jeff said needs to start with the soil.

 

[mikewhite85]

Thanks for all the input guys. I did a soil test this morning in 3 different places. Ph was between 6.5-7 everywhere. Ultimately, I think the cause of the partial defoliation is due to the cold nights and rain we have been having. Ficus are hardly trees that can really take a beating but on the same token they do not tolerate the cold well. The excess of water in the soil from the rains might explain some of the chlorosis, which was minimal. I am beginning to doubt whether the discoloration in the leaves is fungi at all. I suspect the tree will begin to fill out pretty quickly once it starts to get warm again with the spring flush (which seems to have already begun with a lot of trees, especially Chinese elms).

One question I have is why are more of the leaves falling on one side than the other? I assume it's because that side has significantly more sun exposure which creates a greater contrast in the temperature ratio day to day.

For the thrips, they really weren't too bad and haven't yet taken over the whole tree. I will inspect it again if anything changes. Thanks again for the help guys.