We don't know if it is a disease or a pest causing it. There are some miniscule caterpillars on some of the leaves, but we have a lot of butterflies around. The damage has been evident for a couple of weeks and the caterpillars have just hatched, so I don't think they are the cause. Can someone steer us to an appropriate treatment, please? I'll attach two pictures. TIA
Barb
Second pic...
bjf826, see the discussion of "leaf miners" in the post asking is my manderin orange tree going to die. There is a lot of good information there relevant to your trees' problem.
Thank you for providing that information. It certainly looks to be the culprit. We looked at an all-season oil spray yesterday at Lowe's and wondered if it would be applicable in this case. Need to make a return trip, I reckon.
Thanks again,
Barb
Barb, here are some University of Florida sites that may be of help now and or in the future:
http://edis.ifas.ufl.edu/HS122
http://edis.ifas.ufl.edu/XC003
http://ipm.ifas.ufl.edu/agriculture/citrus/brownahoy.shtml
I read that knowing the species of moth whose caterpillar does the tunneling is important as it helps dictate what kind of measures you can take and when. It might be a good idea to take some leaves that contain live caterpillars to you cooperative extension agent for identification and control recommendations. Another thing to consider. If you have a large citrus tree, you may not have to do anything as a large tree can withstand a light infestation. A small tree can be severely damaged or stunted.
Here is another link with a little more information.
Oldude
http://davesgarden.com/community/forums/t/861529/
Wow, thanks Veronica and oldude! Love to learn new things. I'm off with my magnifying glass to see if I can see any of the little baddies. The tree is only about 3' high, newly planted this summer and thus more likely to suffer from such an attack. They are on every section of new growth, so we'll need to deal with it soon.
Thanks again.
Barb
Barb
Oil emulsion sprays should not be applied to drought stricken trees when temperature is above 85ºF. Oil emulsion sprays applied after August 15 can reduce the tolerance of citrus trees to cold weather. You need to be careful with the horticultural oil in late summer. If you have temperatures lower than 25 degrees this winter, you will see leaf drop and the oil makes it much worst. Sorry, for not bringing this to your attention sooner.
Oldude
Uh oh. Looks like a systemic would be more appropriate then? Whole branches of leaves are effected and I would hate to see all those leaves drop. The tree is watered well by a sprinkler system and is still small enough to be covered if and when a freeze is predicted, but I don't think I want to take a chance with the oil emulsion spray. Thank you, oldude, for pointing this out. You folks are great!
Barb
I think a systemic would work fine if you do not want to eat the fruit. Why not give the spinosad or avermectin pesticides recommended in the is my manderine orange going to die discussion?
Treatment on this particular tree is a moot point for now. The eggs and caterpillars I found are soon going to be Giant Swallowtail butterflies. The tree will survive, I'm hoping. If not, then next spring another can go into the ground in its place.
Thank you all for your help with this.
Barb
