Apparent insect damage on fruit and leaves

[Rewton]

A few weeks ago I started to see tiny white spots on leaves and fruit on a few of my figs. The white spots appear to be a powdery substance projecting out from the surface of the plant tissue. It is as if a tiny boring insect damaged the tissue so that a small amount of sap comes out. With the fruit, the damage leads to brown spots. In one of the photos I show you can see the discoloration starting around the white spot where the damage occurred. Does anyone know what causes this and how to treat it? Would mites cause this? I've never seen an insect in the act but I suppose they could be too small to see.

[Erick]

I'm new so I don't know much about this but it sounds like aphids. That's how they feed. I've seen where people take a spray bottle full of water and put a few drops of dish washing liquid in it and spray the plants everyday. It wouldn't hurt anything to try it and see if it helps.. There's videos on youtube about how to do this..

[COGardener]

It's not aphids, they do not bore into the plant. They have a proboscis that they push into the plant to feed on it's juices. Aphids would be visible on the surface of the plant.

[WillsC]

Steve,

Mites are way too small to cause that. It does look like a borer? Did you remove one of the fruit and cut it open to make sure the bug is not inside?

[Rafaelissimmo]

Looks more benign than my situation Steve.

[Rewton]

Wills, I did cut a fig open as you suggested and the damage is clearly superficial. A microscope would be helpful but it definitely doesn't go deeper than the very outer layer of skin. I suspect the figs will ripen normally assuming they don't get additional damage. The more disturbing possibility is that fmv could be spread this way. I think I'll contact my county extension office and see if they have an idea what kind of bug causes this.

[cis4elk]

Steve, I get some occasional spots like that on some of my figs. It seems it's some sort of insect the gives the fig a try and then the latex droplet forms just enough to build up but not drip, then it dries up and hardens. Your bug looks to be a bit more determined to sample that fig than mine though, usually just a spot or two here.
You could have some mites(seperate from the symptoms your inquiring about) on the underside of that leaf though. I had a pineapple plant that was somewhat under some blackberry canes last summer. I left a few blackberries that sprouted in that pot in the fall and they were harboring mites. I knew they were there but didn't think(duh..exactly) they would spread or be interested in my other plants because they were fond of the blackberries. Anyway, now I have mites on several trees and had them on most of my starts(all plants that were in close proximity at one time or another to the pineapple). I've been using a homemade neem spray with fair results, other than the fact that I made the last batch with too much soap or neem or both and burned some leaves in the hot sun the next day. I made a homemade bug blaster a few days ago to use on the trees that are a little bigger, first treatment didn't wipe them out as much as I was hoping so that on is still up in the air. Good to be on top of before they spread, that is if the splotches on the leaves are from mites and not FMV or some other benign nutrient splotch.

[hoosierbanana]

Steve buy a 40x handheld microscope... The fig mite is too destructive to wait around and wonder if you have it. If you want to trade healthy cuttings for one I am in need, since many of my varieties that were hard hit are now not worth propagating from. More a warning than an offer but please take both seriously.

[Rewton]

Brent, I was hoping you would chime in on this. When you were/are dealing with mites did you also see the tiny white powdery specks on leaves and fruit? I guess I thought we were too far north to be affected by mites. All of my figs were overwintered in cold conditions (getting down into the mid-20's at least). I did get some cuttings from a couple outside sources over the winter but they all came from the mid-atlantic or further north.

[hoosierbanana]

The faint blotchy spots are really familiar. Some trees had every fig spotted like that, the fuzzy Etna types were the worst. I am seeing some spots on figs, but they are only showing up on badly diseased branches, unlike last year, and only one had any oozing. I have only seen a few faint spots on leaves this season, maybe FMV or maybe a nutrient problem, nothing that has persisted or worsened. I will look some more tomorrow and take pics, scope for mites again.

I read about people heating their storage spaces, running greenhouses and grow rooms over winter, and fig mites can probably survive on cuttings in the fridge for a long time.

If the spots are a new problem for a tree, spread from one to another and increases as the season goes on it has to be mites. Typical FMV symptoms did not show up until this spring on some trees, they grew well and just had faint spots on their leaves which cleared up after spraying miticides. A few that did have faint spots/mites seem to be totally fine, but I won't really know until I start a dozen or more cuttings and see how healthy they are.

[hoosierbanana]

So I only found 3 figs with sap leaks. I found a few spotted figs on branches that had few or no FMV symptoms also, unfortunately.... Still only Etnas are showing damage. The faint spots on leaves seem to be nutrient related. I spent a good bit of time looking at leaves and saw no mites, one predatory mite actually so maybe one or two fig mites were there. The prospect of finding one or two fig mites on a leaf is grim, the viewing area and depth of field make looking at a whole plant impossible.

Spots on figs











Faint spots on leaves, most likely nutrient/ph and or microbe related... Also note the fuzz left from plant hoppers, they could be involved.


More pics of what I consider "typical" severe FMV symptoms.

[hoosierbanana]

So I found many more sap leaks in the past couple days, I think the rain might have been washing them away. Maybe leaf hoppers? stink bugs? There are not necessarily brown spots associated with them though, I think the brown spots form first and then the skin cracks in that spot and leaks a little.

I may be paranoid about the fig mite, but then again I will be ditching 20+ trees soon and more at the end of the season as a result of last year's infestation so I think a little extra caution is a good thing and I hope it does not wear off too soon. It is a personal choice whether to "worry" about FMV and the fig mite or not but people should know that it can be devastating.

[Rewton]

Thanks for sharing what you are observing Brent. Although I have seen a correlation between the sap leaks and later brown spotting on the fruit, I don't think I have seen this progression on the leaves. I visited a fig enthusiast in northern VA over the weekend and a few of her trees also had sap leaks. Generally she had less damage than me. I noticed on both my figs and hers that the varieties that seem to be the most affected are the ones with the more "sand-papery" texture to the leaves i.e. Mt. Etna's, St. Rita, Bari, and a couple others. Those with smoother, slicker leaf surfaces like Atreano are not affected. A number of people have mentioned insects in the stinkbug family as being possible culprits. If I understand you correctly, it sounds like there is no clear correlation between the sap leaks and mites. I'll continue to see if I can spot an insect in the act of doing this.

[hoosierbanana]

Yes, nothing clear cut. I will keep an eye on things also.

[noss]

What does one put on figs to kill mites of any kind?

Also, Whatever happened to, "Fig trees are not bothered by many pests???"

noss

[hoosierbanana]

Yeah give me my money back!

Neem oil is probably the "best" but works slower than chemical sprays and needs to be reapplied more often, costs more too. Don't count on remedies for spider mites working for fig mites, they are so small they can get inside fig embryos and closed buds.

p.s. I sent you a PM last week Noss, did you get it?

[Rewton]

I purchased a 40x hand held "eye loupe". It seems to work pretty well for magnifying the surface of fig leaves and fruit out in the field. I looked at several different plants that had the damaged fruit and splotches on the leaves (both with and without the small white crystalline spots). I did not see any mites and I looked pretty hard for them. Nevertheless, tomorrow I am starting a neem oil spraying regimen and I will see how it goes.

[AscPete]

Steve,
Just curious, What's your fertilization schedule and potting mix?
My guess would be a nutrient deficiency / availability caused by FMD.

[Rewton]

Pete, for conventional containers it is the 5-1-1-1 with 1 cup espoma plant tone, 1/2 cup espoma iron tone and 1 cup granulated lime per 5 gallons. For the SIPS it is 2-1-1-1-0.5 of pine bark fines/coir/peat/perlite/oil dry with the same additions. During the season, I top dress conventional containers, and add to the reservior of the SIPs 1/2 teaspoon of miracle gro and occasionally some plant tone as well for micronutrients. This is for 5 gallon containers so I increase accordingly for larger containers. To be honest the fertilization schedule is kind of haphazard and this could be where the problem comes from. The other thing is that there is some correlation with the figs that have the most leaf and fruit splotches and the figs that are growing in their potting mix for the 2nd year. So maybe I need to increase the fertilization schedule for those figs. I did notice a major difference with the St. Rita (see my other thread) when I increased fertilizer and it is on its 2nd year in the same potting mix.

[Rewton]

I would add that my in-ground figs (with a couple minor exceptions) have clean leaves. The difference is amazing. That also suggests an issue with nutrients.

[AscPete]

Steve,
Thanks for the reply...

I started adding Ironite to my mix and fertilizing schedule and there has been a marked difference in appearance with that simple addition. I started using Gypsum last year and the addition of Gypsum alone with the fertilizing schedule has also make a marked difference in leaf and fig growth.

Yes, its been my observation that whether the potted trees have FMV infection(s) or not, the increased available nutrients results in visibly healthier growth

[hoosierbanana]

If iron supplements are "helping" your ph is probably too high Pete. Iron is an abundant element, but not very available to plants in alkaline conditions. You might try adjusting your fertigation solution to a lower ph and find you do not need to use as much fertilizer in general due to better absorbtion.

[AscPete]

Brent,
Thanks for the suggestion, the spot checked pH is about 6.5... Which is why I believe that the Gypsum alone (Calcium and Sulfur) are having a beneficial effect.

[fignut]

I came across this thread while researching something else, and believe I know what is causing the damage - thrips. I’d been seeing white drops of sap on the figs - in the morning usually. Later a brown scar is visible. While smooth figs are sometimes targeted, most of the damage seems to be on “fuzzy” figs - Celeste,Hardy Chicago, Florea, etc. If the fig fruit is very small when it is attacked, it can be deformed as it grows.

I’d been searching for the culprit without much luck, when I caught a thrips in the act.

This isn’t a good picture, but it does show the relative size. The insect at 11 o’clock right above the eye is a thrips. The one at 6 o’clock just below the eye is a fruit fly.


There are many species of thrips - I don’t know what I have. They are attracted to sticky traps. I’ve used this one successfully.

https://www.amazon.com/Double-Sided-Universal-Insect-Monitor-10-Pack/dp/B004JTXG72/ref=sr_1_6?ie=UTF8&qid=1492826270&sr=8-6&keywords=Double-Sided+sticky+trap

Some species are attracted to blue, others to yellow. Whatever type I have go for the yellow side of the card.


There also is a predator, the Texas Long Legged fly http://www.insectidentification.org/...g-legged%20Fly that also targets thrips. I see them constantly on my figs - and almost nowhere else. They look like tiny irridescent jewels - very pretty.

Sorry about the links - I couldn't get them to load.

[Rewton]

Fignut, thanks for weighing in. What you are suggesting as a cause makes a lot of sense.

[fignut]

I initially hadn't considered the possibility that it was thrips causing the fig damage, because the damage was quite different from what I was familiar with on other plants. Most of those plants had leaf damage - stippling and striations - with multiple, closely placed holes. But if you follow the link below, and scroll to the bottom of the page, you'll see similar damage on tomatoes to what is seen on figs. http://www.tswvramp.org/vectors/index.html

I think there are fewer holes on figs because the fig sap flows very readily when the fruit is pierced, and the thrips doesn't have to make a lot of holes to get a meal.

Sorry again about the link. I hit the link icon, paste the link - but it doesn't load. I'd be grateful for any help.