Sadly, it appears to be Citrus Greening Disease. It is all over Florida and was confirmed in Texas early last year, too. See link below.

Carol in Jacksonville

Here is a link that might be useful: Citrus Greening Disease

By the way, I bought my current home 4 years ago and it came with a HUGE honeybell tree. It seems to produce heavy every other year, sort of taking a "rest" in between (but I still get more fruit than I can eat on the "off" years). I am certain that it has citrus greening. Many of my fruits appear like the ones in your picture, but I haven't had flavor problems with the ones that look like that. Now, I also have fruits that are too yellow (often too small and too yellow), and they're definitely not edible.

I'm fertilizing more often with less fertilizer each time, trying to keep nutrition more consistent and less spikey. I'm also looking into nutritional sprays, such as KeyPlex, and performing some invigorational cutting this spring in the hopes that I can keep this tree going and producing at least some good fruit next year (which should be an "on" year).

Here is a link that might be useful: KeyPlex Citrus

Here's a photo of the honeybell tree from Jan 2010. It still looks about the same today. Like I said... it's huge.

You know, I wrote a letter to the state agriculture Commissioner as well as my Florida state senator and state representative about greening disease and how important it is to destroy abandoned groves which are serving as cesspools to spread this disease and it's vector. Around me there are miles of abandoned groves and the trees are so diseased it's disgusting.

Not one had the decency to even acknowledge my letter. Truly disgusting to me, especially from Adam Putnam, who seems to be more interested in his political future than DOING HIS JOB.