Avocado pest--small black hole and chalky white exudate?

This is the first year I’m letting my Pinkerton fruit, and about one third of the fruits have one or two tiny holes, and then chalky white stuff that seems to have come out of the holes. I figure there’s some bug in there. Does anyone know what it is, and secondly, will it make the whole avocado inedible, or should I leave them on the tree and expect to cut out the bad part? Since then I’ve bagged all the fruit, as you can see from the purple organza bag in the background, but I don’t know if the mesh will keep out the bug on the ones that don’t have the bug yet. Any clues? Thanks folks!

Lizzy, this has me a bit concerned. Check this out, and then call your local ag agent and see if someone can either come out and look at your trees, or if you can bag up the fruit and mail it to them:


Yikes! Thanks for the heads-up Patty. I’ve never tried to find an ag agent before. Is that a county post? I see online that there’s a county agricultural commissioner–would that be the person to contact? Thanks.

if you have another one infected, am sure there are plenty in this forum who could help identify. All you need do is dissect, probing through the tract, then post pics. The white stuff seems to be the poop of the offending critter.
btw, those baggies seem to have a fine-enough mesh to prevent entry of future maggots/bugs.

Yes, CDFA is who you want to look up. You can also try callilng UC Riverside and ask who to speak to regarding avocado pests. Julie Frink is the curator of the avocado orchard, but I am sure you can find someone there you can send you photo to, who can help you diagnose the pest. Let’s hope this is not what I found in the article. I have never seen anything like that before. I agree with Juju about your organza bags. That’s a great idea.

The County Agriculture Commissioner’s office is probably not the most effective contact to start with.

You can contact your local agricultural extension office for the county. Those offices tend to be up to date on ag issues for the area. They also have direct connections for getting testing and answers when necessary.

Contact Information

Santa Cruz County
Cooperative Extension Santa Cruz County
1430 Freedom Boulevard, Suite E
Watsonville, CA 95076-2796
Phone: (831) 763-8040
Fax: (831) 763-8006

Mark Bolda
Office Hours

Monday - Thursday: 8:00 a.m. to 5:00 p.m. (closed 12:00 - 1:00 p.m. for lunch)

Fridays: 8:00 a.m. to 12:00 p.m. open and 1:00 - 5:00 p.m. by appointment

Thanks for your info, all of you. I’ve left a couple of messages, and hope to get a call-back next week. I will keep you posted!
Responsible Fruit Grower :flushed:

Holy cowroonie, Patty, you weren’t kidding, they take it seriously! Just talked to the ag commissioner’s office and they want photos and samples and they’ll be sending them to a lab. They’re sending them to “the state” so maybe it didn’t matter which of the numbers I called if they all want to send it to the same place. Scary. Hope it’s just a false alarm, fingers crossed.

I hope so, too, LIzzy, but I sure do not not any pest that makes this sort of specific damage, save for what I sent you. It’s a big deal, and VERY glad you caught it. Please keep us posted, hoping for something easier to treat for you.

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Here’s an update, but nothing confirmable: The first samples I sent via the county ag commissioner that went to the state lab in Sacramento yielded “inconclusive” results. I found an avocado with much more damage, and took that down to Watsonville so they could send it in as well. One thing they told me, confirming something I’d seen online, was that the white exudate that comes out of the holes is simply the avocado’s response to any damage. Apparently it is composed of a lot of fruit sugars and if you damage the wood or fruit of an avocado it oozes white stuff. A woman at the ag commissioner’s office says that it even oozes white when it has a fungal infection, so they are testing the most recent sample for that as well. The most recent one I sent in seems to have a big hole from something that also ate through the stem, as well as smaller entry and exit holes with a lot of white stuff between. Curiouser and Curiouser, as Alice said in Wonderland…

Thanks for updating, Lizzy. I’ve been hoping you would.

Here’s hoping the problem is a common pest that is easy to control.

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Thanks, Lizzy. We are all very anxious to hear the results.

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Lizzy, have you cut any open to see if any larvae was present inside?

Yes, I cut open a few of the affected fruit, but it seemed that whatever was in there had already departed. There was a lot of frass though. I left some uncut in the samples I sent in, in case they could find whatever organism is causing the problem.

Well, it’s still inconclusive. The county people contacted both specialists at UC Davis and the state. They think it is faintly possible that the larva/inchworm from the light brown apple moth may have caused the damage. If so, that would explain why whatever is causing the holes seem to just eat a bit and then change their minds–in other words, they don’t go into the pit as the south american seed weevil borer things (that Patty AND the UC Davis people were concerned about) tend to do. They want me to continue to try to find an actual larva or pest, so I will be vigilant about checking the avocados. (Feel free to remind me!) Since the bugs haven’t hit all of the avocados, and they are bagged, and there are only about ten since the tree’s still young and I thinned, and since it’s late in the season, I have my doubts that I’ll find anything this year. I will definitely keep an eye out next year too!

Oh, and when I moved in here in 2008, the Gravenstein was completely infected with coddling moth, and they are all over Santa Cruz county. So maybe the fact that I’ve been really careful to clean up the apple tree, getting rid of every speck of debris they could hide behind, and bagging the fruit, etc., has made it so that the apple moth larvae are trying to find other things to eat, like my avocados! I wonder if anyone else has ever had apple moth larva sample their avocados?

PS Patty they also sent my photos to Mark Hoddle at UC Riverside, the one that article you linked is about. I don’t know if they’ve heard back from him, but I’ll update if I hear anything!

Lizzy, very, very glad they did that. Please keep us posted.