Aphids... Solution?

[Well_Well_Well]

As I’ve posted before, a presentation I viewed claimed aphids only target unhealthy plants, because healthy plants make too much sugar (dangerous–aphids can only filter out so much sugar); since, if memory serves, what he said plants need to be healthy (create sugar) is light, oxygenated roots, good water (I would think you already know it needs filtering to remove chlorine and chloramines), and nutrition (ideally, supplied by healthy soil microbes), I figured it must be the nutrition (in part due to underdeveloped healthy soil microbes) that was a broken link that was leading to an aphid infestation on my apple trees.

Well, I’d gotten surgery, so I’d had an excuse to not have to water them as often (twice daily was what they needed). Well, I think a week or two after I stopped watering them as often, they must have been stressed under the AZ sun, because I found an aphid infestation. It was my fault.

Anyhow, I remembered the presentation said there were the aforementioned factors for plants being healthy (making sugar–repelling aphids), so, after trying watering them for a few days, and seeing no difference in the aphid population, I went after the aphids by hand (these are 1 and 2 year old dwarf trees, so it wasn’t a massive job), but, after doing this for a couple days, I remembered they needed nutrition to make sugar, and then I remembered I had some rock dust that I wanted to try to see if I could “cheat” (ie, ideally, nutrition comes from soil microbes), so I intentionally left a part of the aphid infestation in place, to see if the application of some rock dust nutrition would do anything to help the plant make more sugar (because they’d leave if the whole theory was true, and if the rock dust was a good source of nutrients the plant needed).

I don’t believe 5 days passed before the aphids were gone.

Now, again, I use filtered water, and the soil is very aerated (I can pour 4 gallons of water directly into the soil around the tree, and it will not stand and pool for even 5 seconds), etc–I don’t know if you have the same conditions I do, so I don’t know if everything will work as it has for me–but it seems the pillars of what the guy said about health for plants, and the ramifications for having healthy plants, are true : aphids cannot stay when your plants are healthy, and you get them healthy by making sure they have enough light, quality water, nutrition, and oxygenated roots (I’m pretty sure that was one thing he mentioned).

You don’t have to use rock dust. A good compost can function similarly–and I’m sure a lot of you know a lot of good ways of getting proper nutrition into your plants (though I would not recommend the “spikes” of nutrition, because, supposedly, that will inhibit microbial flourishing–I’m not going to discuss that claim, or get angry, you either take it or leave it). I’ve heard of weed teas, etc, and maybe those will do.

The point is aphids aren’t an issue at all, your plant just needs some help to be more healthy–same as most human diseases go away when you’re doing what you need to be healthy.

Not going to argue with anyone who thinks aphids are an actual problem that can’t be solved, just sharing good news I hope you’ll enjoy.

[TNHunter]

I started a isons mucsadine last fall and an oh my this spring. They have both grown very well this season. The folks at isons encourage you to push them with regular fertilization that first year to get them up to the trellis wire and then run 10 foot up and down the wire.

The pic above was taken a month or more ago.

The vines looked very healthy all year… i watered them often as I was fertilizing with high N miracle grow… and we had two periods of drought this season.

Both vines … 2 or 3 times this summer had some aphids and ants just on the growing tip of the vines.

Sometimes I just rubbed them off … occasionally gave them a shot of sevin spray.

They never looked unhealthy… but suppose they could have been stressed by our super hot and dry spells.

TNHunter

[Well_Well_Well]

If the plant is making plenty of sugar, there will be no aphids/aphids will go away.

Well wishes with your garden!

[Well_Well_Well]

I noticed with my pear tree that if I don’t put lots of support water in the noon/afternoon it will stress terribly. Everything needs extra water here on the mountain in AZ.

[TNHunter]

It did not look like the aphids had much choice… the ants were forcing them to stay… farming them.

They do that on my okra too… but i never bother them… the okra just keps on growing well.

[Well_Well_Well]

Lol

[Well_Well_Well]

That’s a lovely vine there

[pith]

I’ve been reading up on aphids , and some are almost entirely ant dependant. The black peach aphid seems to be ant dependant. Stopping the ants has stopped the black aphids so far. The green leaf curl aphid doesn’t seem to need any ants, and is doing a number on my mariposa plum. My aphids seem very picky. They don’t touch pluots or sweet cherries for some reason, but peaches and japanese plums get really infested if the ants are allowed to farm.

[Well_Well_Well]

I don’t know about the differences between aphids, but the good news is that healthy happy plants won’t have them at all (for the reasons laid out).

[alan]

My understanding is that the relative vigor of a plant can affect its attraction to aphids but that the issue is much more complicated than that being all you need to know to control aphids.

Young cherry trees, for example, can be damaged by aphids no matter how healthy they are before being populated by the pests. This can vastly reduce annual growth and delay the development of size and crops.

I don’t know if there are species for which vigor alone is a panacea against damaging aphid attack but I certainly am not going to believe it based on a few anecdotes… unless of course they are my own .

In my region, leaf hoppers are a greater problem to tree growth than aphids anyway. Perhaps the same issue applies to them but maybe not. I have certainly seen a great range of their activity from site to site on same years. Interestingly, they don’t seem to attack the more vigorous J. plums like they do E. plums, which can be seriously dwarfed by them. Leaf hoppers seem capable of killing new grafts because all their growth can still be tender when the growth on the rest of the tree has largely hardened off.

[Well_Well_Well]

The claim is eventually (and lastly) even grasshoppers will not show interest in eating your plants, bc insects eat unhealthy plants, but I only have experience/success with aphids.

Grasshoppers have greatly reduced, but that’s probably due to having laid lots of mulch down lol–this year, I saw scant few on the blackberries, where they normally reigned, but they still showed interest, so they can’t be that far along into health, and, so, i keep working toward healthier happier soil and plants.

I think leafhoppers would be more along the lines of grasshoppers than aphids (right?), and would require a lot more health to repel than would aphids.

[alan]

@Well_Well_Well

I think leafhoppers would be more along the lines of grasshoppers than aphids (right?),

Grass hoppers eat the entire plant. leafhoppers are sap suckers like aphids. Here is what Chat has to say about their differences. It is fascinating and your topic coaxed my curiosity on the subject.

I asked, “Do leafhoppers fall in more or less the same category as aphids in terms of favoring high protein sap”

ChatGPT said:

ChatGPT

Leafhoppers and aphids are both phloem-feeding insects, but their feeding preferences and impacts on plants differ in several ways, including their relationship with sap nutrient content, such as protein (amino acids) levels. Here’s a comparison:

1. Feeding Preferences: Aphids vs. Leafhoppers

• Aphids: Aphids prefer sap that contains a higher concentration of amino acids (proteins) because they need nitrogen for growth and reproduction. They tend to target plants that either have increased levels of amino acids due to stress or have an altered nutrient profile, which they can benefit from. Although aphids can attack healthy plants, they often thrive on stressed or nutrient-rich plants where nitrogen content is higher.
• Leafhoppers: Leafhoppers are also phloem feeders, but they feed in a somewhat different manner compared to aphids. While they do consume phloem sap, their feeding style involves piercing plant tissue and extracting nutrients from multiple cell types (both phloem and xylem in some cases). Leafhoppers are not as strongly tied to amino acid content in sap as aphids. Instead, they are opportunistic feeders and can cause mechanical damage to plants regardless of sap quality. They can thrive on a wide variety of plants, including both healthy and stressed plants.

2. Sap Nutrient Content (Protein/Sugar Balance)

• Aphids: Aphids are more selective and sensitive to the balance of sugars and amino acids in the sap. If the sap is too high in sugars and low in nitrogen-based compounds, aphids may not thrive as well. They prefer sap that has a higher nitrogen content (amino acids), which provides them with the nutrients they need to grow and reproduce. Plants under stress often produce sap with a more favorable balance of these nutrients, making them more attractive to aphids.
• Leafhoppers: Leafhoppers are less selective about sap nutrient content than aphids. They do not rely as heavily on sap’s amino acid content, and their feeding strategy causes physical damage to plant tissue, often regardless of the nutrient composition of the sap. Leafhoppers are also more likely to feed on both healthy and stressed plants, suggesting that they are not as limited by sap composition as aphids are. In fact, some studies indicate that leafhoppers may target healthy plants to take advantage of their higher overall vitality.

3. Impact on Plants

• Aphids: Aphids primarily cause damage through nutrient depletion and by transmitting viruses. While aphids can harm plant growth, especially when populations are high, their damage is often related to indirect effects (like virus transmission) and their preference for sap with a higher nitrogen content.
• Leafhoppers: Leafhoppers cause more direct physical damage through their feeding, which can result in “hopperburn” (necrotic areas on leaves), leaf curling, and reduced photosynthetic capacity. They are also vectors for various plant diseases, such as Pierce’s disease in grapes, which is caused by a bacterium transmitted by leafhoppers. Leafhoppers can damage healthy plants extensively even if the sap isn’t particularly high in proteins.

Conclusion

Leafhoppers do not fall into exactly the same category as aphids in terms of favoring high-protein sap. While aphids have a more direct relationship with sap nitrogen content and prefer plants with higher amino acid levels, leafhoppers are less selective and can feed on both healthy and stressed plants, causing damage that is more mechanical in nature. Both insects can have detrimental effects on plants, but their feeding behaviors and nutrient preferences differ.

[alan]

I should mention that you live in an area that tends to be mostly dry during the growing season so what applies to pests in your environment may not apply to them in my humid region in downstate NY. We have all kinds of pests that thrive in very healthy trees. Sometimes high vigor helps though. I’ve never lost a vigorously growing peach tree to borers, for instance. They produce a lot of sap as a defense mechanism which probably slows down the borers, perhaps to the point of trees outgrowing damage and maintaining a cambium bridge. At the very least, it makes their presence very obvious to the orchard keeper so that person has time to act and protect the tree.

[Well_Well_Well]

Oh OK, then the leafhoppers should be easy to get rid of!

Thanks, you and ChatGPT, for the elucidation!

[Well_Well_Well]

Haven’t learned about borers yet. I hope the same solution applies to them!

[Well_Well_Well]

As far as insects attacking “healthy” plants : when i made my mistake of not watering, stressing the trees, and they got aphids, i noticed they were focused/located only on the new/newer growth/tips… where, presumably, the tree was not as strong as in its other parts. Weak points. Every tree must have them, so gotta get the plant to be so healthy even its weak points are strong.

The “weak points” of my apple trees are clear of aphids, weeks later, still. The aphids must’ve come from the Pine, which I’m treating now, and which has slowed “weeping” (aphid poop) considerably. I used to have to wash the windshield daily, now I think it’s been a week and finally I’ll have to wash it. It’d stopped entirely last year after applying some of the very little bit of my compost that came out half decent, but I remember in a presentation on that compost he said it needed to be applied annually, especially at first (but that was with farming, so I was uncertain if it applied here as well).

[danzeb]

Sometimes what is true for one set of weather and soil is not for a different set. There are approximately 1000 species of aphids in North America. Does anyone know if they all attack fruit trees for the same reason?

Does a quote from this source hold true to all species of aphids?
Impacts of Fertilizers on Insect Pests - SARE
“Although more research is needed to clarify the relationships between crop nutrition and pests, most studies assessing the response of aphids and mites to nitrogen fertilizer have documented dramatic expansion in pest numbers with increases in fertilizer rates.”

[Well_Well_Well]

I wouldn’t know about “nitrogen” fertilizer. I gave my plants rock dust, which I believe would be a mineral supplement. It looks like you shouldn’t give it nitrogen fertilizer to get rid of aphids lol

[pith]

hmmm. I feed my trees high nitrogen fertilizer after the blossoms are finished. Might have to rethink this. The aphids appear about 2 weeks after blossoming is finished.

[Brisco]

Whenever you have a problem, almost always the best course of action would be to solve the problem directly.

These days it’s profitable for influencers to present unique holistic approaches, such as over-watering your trees to get rid of aphids, ore under-fertilizing them, or any number of “organic” approaches.

These approaches are somewhere between inefficient and completely ineffective but they get views and likes so they are hugely profitable for the influencer.

The bottom line is that if these approaches worked well farmers would be using them already. Farmers don’t buy pesticides and sprayers and labor just because they like pesticides. It’s because they are the best way to get rid of the pests.

The relationship between sufficient watering and aphid resistance has been well established. There is no doubt it works for some kinds of plants and some kinds of aphids.

That doesn’t mean it’s worth decreasing the fruit quality and the time and effort to water once or twice a day. It may not even work for the kind of aphids you have.

I also believe that properly fertilizing a plant could increase aphid presence for some kinds of aphids and some kinds of plants. Again, is it worth the decreased fruit amount or quality?

Just solve the problem you have with solutions specifically designed for that kind of issue and you’ll save yourself a lot of effort and disappointment.

Always keep in mind that some people live in areas with very low pest pressure and things that may work for them may not work in a more typical environment.