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Aphids on crepe myrtles :(

Randy Man
2 months ago

Aphids has attacked my landscape this yr. They are attacking my crepe myrtles and turning everything around them black. Crepe myrtles are my favorte tree so ive got alot of them on my acre and half lot and about 90 % of them have aphids. How I noticed was they didnt bloom this yr. I have reds, pinks, whites and lavenders. The mauve and reds bloomed a little but barley anything. The lavenders took the big hit as they have now have lost about 80 % of thier leaves and look bad. These crepes are pretty mature so some are over 10 ft, I have a commerical backpack sprayer and been hitting all them pretty hard the last 6-8 weeks but I dont think I am getitng anywhere. They just wont go away!! Any ideas? Ive used bifen XTS, peppermintsoap and oil and malathion over the last 6 - 8 weeks. Since the CM are tall it takes me almost 3 hours to treat all of them. I also prune the tops of them every yr(late winter). Glad I did or I wouldnt be ablle to reach the aphids at the tops. Theres no way they can survive everything Ive thrown at them? or they just fast reproducers?? My guess is the black mold from the honeydew was so bad that it cut off photosyntheses and caused the trees to not bloom and go into dormancy faster? Can anybody confirm that? After I treat I can come back 2-3 days alter and shake the tree and see very small white flies moving around like I did nothing, So frusrating!



Comments (32)

  • cearbhaill (zone 6b Eastern Kentucky)
    2 months ago
    last modified: 2 months ago

    Well, all I can say is all that "bifen XTS, peppermintsoap and oil and malathion" has driven away your predator insects. If you leave aphids alone or simply blast them away with water then predator insects will show up in droves to eliminate them.

    It's nearly fall. I'd stop spraying stuff, keep them blasted away with water, and hope for better last year.

    For me simply not reacting to the presence of insects with panic seems to work best. Aphids are not a catastrophe and natural predators are usually enough.


    "After I treat I can come back 2-3 days alter and shake the tree and see very small white flies moving around like I did nothing"


    And you are certain that these flies are winged aphids? Proper identification of the pest is 90% of treatment IMO.

    If you are in the USA please call or email your local cooperative extension agents office- they will have a wealth of information on every topic imaginable from veggies to flowers to trees to pests and so on. Lots about various pests and it is all tailored specifically to your immediate area- because they are county specific they will be intimately familiar with everything going on around you and can offer thoughts on controls. They are happy to answer your questions- you paid for them with your tax dollars- use them!

    Find them by googling "your state+county+cooperative extension."

  • dchall_san_antonio
    2 months ago

    For me simply not reacting to the presence of insects with panic seems to work best. Aphids are not a catastrophe and natural predators are usually enough.

    OMG! That is such a great philosophy.

    Proper identification of the pest is 90% of treatment IMO.

    Again, well said. Whether it is a weed or a bug, you cannot treat a pest with the wrong treatment.

    My first response to tree or shrub issues is to determine whether I care about what's happening. If I care and I see caterpillars, then I spray with a biological caterpillar disease called BT Worm Killer. If I don't see caterpillars, as in this case, then I spray with molasses diluted down to 3 ounces per gallon of water. Usually I put a teaspoon per gallon of baby shampoo to help the molasses water stick to the bark and leaves of whatever I'm spraying. Using a hose end sprayer I hit it as hard as I can as if to wash the tree with the spray.

    I have been fertilizing only with organic materials since 2002, and I don't often see issues with my trees and shrubs. It has been demonstrated in greenhouses that aphids are less attracted to plants in organically supplemented soils. Had I not seen it myself I would be skeptical, so I'll try to describe what I saw. The greenhouse owner was experimenting with soils and compost. His standard soil was Walmart generic soil. He used Walmart soil so that anyone could replicate his experiments. Then he mixed 10% compost and used that for the experiment. Then to the compost mix he added 10% basalt sand. He had 3 plants in 3-inch pots touching each other. The canopies of the three plants were growing together and aphids were clearly present. When he pulled the pots apart, only one plant had aphids. Even though the three plants were growing together, the aphids were not attracted to the plants with the compost mixed into the soil. I used to have a tremendous aphid problem with my roses until I started with organic fertilizers. Since then I don't get aphids...at all.

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  • gardengal48 (PNW Z8/9)
    2 months ago

    A dormant oil spray will work if the problem - the sooty mold - is caused by scale. But dormant oil will have no effect if aphids are the source as aphids are never present during dormancy.

    The sooty mold is not the real problem.....only a symptom. It is a fungal organism that develops on the secretion of sucking insect pests (which both aphids and scale are) called honeydew. It is typically more unsightly than actually harmful unless so severe the tree is unable to photosynthesize through the layer of mold. That almost never happens. Get rid of the insect pest that is generating the honeydew and you will also eliminate the sooty mold.

  • Nidnay
    2 months ago
    last modified: 2 months ago

    Dormant oil WILL work on aphids if you spray while the tree is dormant.

    “Dormant oil sprays can control a variety of insect pests such as aphids, mealybug, thrips, whiteflies, adelgids, caterpillar eggs, leafhoppers, scale and mites. ... Because dormant oil can be an effective aphid control, and aphids vector and spread viruses, it could be said that it also helps reduce plant viruses.”

    “Horticultural oils work well to control insect pests and, if used properly, can be a less toxic approach than chemically based insecticides. A dormant or delayed dormant application can kill many of the overwintering insect pests that would normally plague plants in the late spring, such as aphids.”


    ”Dormant oils are especially useful for treating overwintering eggs of insects that curl leaves in the spring (such as aphids), the overwintering eggs of tent caterpillars and leaf rollers, mites that overwinter on conifers, and scale nymphs and adults. These oils kill pests by either blocking the spiracles through which they breathe or interfering with their metabolism. Using horticultural oils in favour of insecticides is now widely recommended, since oils pose little risk to humans, other mammals, birds or beneficial insects; don’t cause pests to build up a chemical resistance; evaporate quickly; and can be applied using existing spray equipment (always follow package directions to the letter).”

  • cgtmc
    2 months ago

    I have used systemic with success , but you need to time the use of them, after they bloom or before. They are non selective and will kill the good bugs too. If they are not in bloom, only the aphids and scale are killed.

  • Randy Man
    Original Author
    2 months ago

    nidnay, What dormant oil did you use? Its the first time ive heard of it? Is it simulaR to neem oil or horticulture oil?

  • Nidnay
    2 months ago

    This is what I used….


  • rifis (zone 6b-7a NJ)
    2 months ago

    Randy Man:

    What was the status of flower bud development on the lavenders, reds and whites 6 to 8 weeks ago, just before commencing the spray program?

  • ken_adrian Adrian MI cold Z5
    2 months ago

    where are you.. big city name ...


    and when will mother nature take care of the immediate problem thru cold temps???


    there comes a point in fall ... when further active means are not necessary .. for many of us ..


    like my MI when i wake up this morning and its 46 outside.. and its many weeks early and my houseplants are still out there.. whats that all about ...


    and at that point we change tactics and start thinking about prevention and attacking in dormancy next spring ... which can be hard to do.. when you want to kill al the little chuckers now.. and i mean RIGHT NOW ...


    ken



  • gardengal48 (PNW Z8/9)
    2 months ago

    Dormant oil may kill off any over wintering aphid eggs but there is no guarantee aphids will not reappear in season. It may help to limit aphid populations by smothering pre-existing eggs but dormant oil will have NO impact on what may happen in warmer weather when the tree is budding out or in leaf. IOW, any dormant oil spray is unlikely to be 100% effective for aphid control.

  • krnuttle
    2 months ago

    I don't know where you live but any poison you put on the CM will also affect the lizards. Poisons are like a forest fire, killing everything in their path. Most people do not consider Lizards and frogs in their pest control program but they are a big part of mine. A couple of months ago we had dozen of baby lizards on our porch, It seemed like with in weeks they were full size. One lizard can live on the insects on one small bush all winter. (We frequently find on late in the winter that came in on the potted trees. )


    For natural insect control you need to have all of the elements of a biological system. Birds, Snakes, Lizards, frogs, and all of the killer insects.

  • Randy Man
    Original Author
    2 months ago

    rifa.the lavenders didnt bloom at all. I only have 2, but they are about 17 yrs old., The whites bloomed very sparingly. The whites on my back yard property line bloomed a little better but still affected, those are only 3 yrs old. I have over 30 whites . The reds and dark pinks bloomed very sparingly like the whites. I have about 10 of these, The reason I have so many whites is I found a way to root that color with pretty good success rate, big baby plants too.. I since have realized that I dont need anymore cause they grow pretty agrresive.

  • Randy Man
    Original Author
    2 months ago
    last modified: 2 months ago

    ken, I am in chatsworth ga near chattanooga

    I am no expert but it seems it would be harder to kill them when they are in the ground. I am assuming thats what they do during winter like most bugs? They are so tiny! I hear people say just wash them off with a water hose. Ive heard comments about they wont get back up there. Well how did they orgianlly get up there? I noticed the aphids about 8 weeks ago BUT i think its been going on a little longer than this because I always noticed sap on my truck hood last yr and possibly longer. I park my truck slighly under a dark purple myrtle.. I always thought it was what the crepe myrtles naturaly drop and didnt think much about it. Well this yr I noitced they didnt bloom and that got my attention and started investigating. I also noticed my trunks was stating to turn black too but also thought that was just nature. I did watch a lawn guy that I folow on YT and he uses a product that you feed the roots and when the aphids try to suck the sap it kills them. This is done in the spring. Ill go share the video

  • Randy Man
    Original Author
    2 months ago



  • Randy Man
    Original Author
    2 months ago

    heres a pic of my older crepes.I just trimmed them(ithis was late feb 2021).. These are about 17 yrs old. I have a lavender, pink white,lavender pink white. They put on a show this time of the yr but didnt this yr :(. . I planted these when I bought this property 17 yrs ago(they are probaly 2 yrs old from nurseery so I would guess they are 20 yrs old.



  • Jinx
    2 months ago

    Cutting them so severely makes them much more prone and vulnerable to diseases and insects.

  • Randy Man
    Original Author
    2 months ago

    @ knuttle I am still seeing frogs seen one 2 nights ago.

    I always spray bifen xts around my house foundation every yr for the last 4 yrs and I have a school of thiose blue shiny lizards that lives around my house foundation and it doesnt effect them. I am still seeing them like crazy, if anything I think they have multiplied.. They love to come and lay around in the sun in the front

  • Randy Man
    Original Author
    2 months ago
    last modified: 2 months ago

    Jinx, I dont know if thats true, I have some 3 yr old ones that I didnt cut and it has aphids bad too


  • Nidnay
    2 months ago

    Oh Randy….this is so sad. Not to criticize, but you do know that you committed the cardinal sin in the way you pruned your crepe Myrtles?

  • Randy Man
    Original Author
    2 months ago
    last modified: 2 months ago

    @ nidnay, I like to top mine. I like the look better . Apparently I am not the only one becuase ALOT of people in my area do this. Ive see them in my area that are just let go and they look so overgrown, especally the white nanchez. They grow very fast here

  • Jinx
    2 months ago

    It is true. Doesn’t mean healthy ones won’t get it, but that kind of topping 100% makes the crapes weaker.

  • Randy Man
    Original Author
    2 months ago
    last modified: 2 months ago

    jinx, Ive been doing it the last 10 yrs and they always come back strong and you cant even tell it in late april with all the new shoots of growth.They always look great. They put on a show that, looks like a rainbow late summer every yr excpet this yr. Its been confrimed that crepes give you more blooms with a prune? I am pretty sure i read that more than once.. I did go a little lower when I cut this past feb but just a little lower. Could that have been a contrubtor for me getting aphids? your opinion yes, my opiinion, I dont think so..

    I know people who wants thier crepes removed and they cant kill them lol. I dont think there is a way to kill them? Well take that back, I bet aphids could kill them IF they attacked it for a whole 12 months without being treated but fortunaly aphids go dormant. Ive never seen mine look this bad before.

  • rifis (zone 6b-7a NJ)
    2 months ago

    Was there visible development of flower buds (which later sucumbed to disease), or did flower buds fail to visibly form at all?

  • Randy Man
    Original Author
    2 months ago
    last modified: 2 months ago

    rifis, on my light purple ones(17 yrs old) they didnt form at all, not one. . 2 of the older white ones maybe put one or two flower buds, the dark pink and red put on 3-4 flower buds. They have always put 20 or more every season.. I know when I top them every late winter there is always alot of dried flower buds, I know because I have a mess to rake up. Its gonna be wierd trimming them without flower buds/very few.. Its like the last 60 days they just quit working or shut down. Hopefully they will rebound come mid spring and i am very confident they will.


  • Randy Man
    Original Author
    2 months ago
    last modified: 2 months ago

    I guess I should have been more patient before starting this thread . I made this thread less than 24 hrs after my 3rd application of malathion. Someone from another thread had good success getting rid of aphids with malathion and after I seen the priceI went and bought a jug of it at home depot for $15. Very affordiable IMO and you only use a teasppon-2 teaspoon per gallon.. The malathion migth have been effective.

    I decided to wash my truck, main reason is ill know if the aphids are still featsing. I may have stopped them as its day 2 and no sign of honey dew on my truck hood, fingers crossed, It may have not been malathion, Its been gettiin the lows 50's at night, so maybe mother nature is causing them go dormant ?

  • cgtmc
    2 months ago

    Crepe myrtles only bloom on new growth, so if they aren't blooming, they may need a little fertilizer. The proper way to prune crepe myrtles is to remove the entire cane. They should only have between 3-5 trunks, 7 if you must. A good site to read about them is "Neil Sperry's gardens". He can explain about crepe murder, aphids, and scale much better than I.

  • Randy Man
    Original Author
    2 months ago

    Well today it got up to about 88 and was mowing around 6 pm this evening and noticed the white flies flying around after I shook one of my many crepes. I also still seeing aphids still on the leaves. I just cant win this battle :(


    Is the white flies whats laying the aphid eggs on the leaves?? Also once the aphids are dead will they fall off the leaves? If I am stiill seeing the white dots on the leaves that means they are alive still?? its hard to see the white flies flying without sunlight becasue they are so small.

  • Nidnay
    2 months ago

    Randy….don’t worry about it for this season. Apply the dormant oil in the spring before the crepes leaf out and you’ll be good to go.

    Randy Man thanked Nidnay
  • Randy Man
    Original Author
    2 months ago
    last modified: 2 months ago

    Ive also been battling diseases in my bemuda lawn for a couple of yrs and every fungus treatment i threw at it didnt work either. I really belive its not disease even though it looks like it is,. I got to thinking could it be the aphids causing that issue too?

    As you can tell ive been battling some issues on my property

  • cearbhaill (zone 6b Eastern Kentucky)
    2 months ago

    "Ive used bifen XTS, peppermintsoap and oil and malathion over the last 6 - 8 weeks."

    "every fungus treatment i threw at it"

    "my 3rd application of malathion"

    ""I always spray bifen xts around my house foundation"

    "Is the white flies whats laying the aphid eggs on the leaves?"


    Do you not see a pattern here?

    I've gardened in two climates for 40 years and haven't yet used nearly as many chemicals as you have listed above in one single thread- it's just not necessary.

    Not intending to be mean here but there are people whose "go to" reaction to anything is "Oh, gotta spray something!" It's a knee jerk urge to act that would be FAR better served by doing some research to identify the pest- are they white flies or are they winged aphids? You need to know.

    By doing all this excessive spraying you are running off the predator insects that Mother Nature handed you on a silver platter. They are out there- stop spraying stuff so they can move in and do their thing.


    Stop tossing chemicals around and call your local cooperative extension agent. Send them photos via email or take some leaves in for inspection- I've even had them come to my property to help ID a problem. Find them by googling "your state+**county**+cooperative extension."

    They are experts on your LOCAL issues. IT's FREE.


    Also- it's October. It's done.

    Clean up all your leaf litter and stop buying jugs of crap.

  • Randy Man
    Original Author
    last month

    This is what I have flying around all the time. Very hard to see without the sun shining on them. You can see in the background what they have done to my crepe myrtles.