Agaveville

Have had them here attacking one or two Agaves for years -- knocked 'em down regularly but could never kill them off. Now, they have swept across more than half my property, killed some plants, and left several others in a sorry state. It was hard to watch, but that was all I could do with one hand, as they grew out of control after my surgery.

Now my surgically repaired hand is about 25% functional, so I finally treated, and it wasn't easy, but should be easier next month. Sprayed all Agaves and Yuccas with Avid, and drenched with imidacloprid at about 3x the strength I use for weevil prevention.

Mealys attack cactus too, don't they? Should I spray, drench or both?

Sorry to hear about the mealys. I didn't even know they attacked xeric plants until recently when my friend up in Michigan sent me a picture of an agave I gave her plagued by the furry little beasts. I've had problems with them on my coffee plant and my gardenia but never on my agaves/cacti/aloes, until I noticed a few happily curled up in the core of my A. utahensis v. nevadensis

Thanks for sharing your treatment regimen. I'd been using Neem oil on my coffee/gardenia, but it hasn't worked all that well. Seems like they dry up and die but then a week or so later they're back in full force. Gotta pull out the bigger guns.

Steph, I'd guess you've read about all these simple, organic solutions, as have I, but those are for house-plants in an extremely controlled environment. Once out of doors, they are more pervasive and far more difficult to manage.

You know, it never struck me that Mealies might attack non-succulents. So I guess I'll have to treat everything....

I have had bouts of this here and there, usually one or two plants start getting it bad, others seem untouched. They seem to particularly like A. gentryi 'jaws' for some reason. I usually can keep it from spreading to other plants relatively easily, but wiping it out altogether is slow but steady. I've been successful using Sevin and spraying liberally. Also, if I see the new leaves opening and the newly exposed "gap" replete with the suckers, which tends to be the case if it gets bad, I have taken to using a Sevin-soaked cotton swap to wipe them out whenever I can reach, that or just spraying directly down into the newly unfolding leaf to soak 'em. Not pretty, but it seems to work with enough applications, and I haven't noticed ill effects on the plants as of yet. I've no particular reason to use Sevin over anything else, other than it seems to work and is readily available (and cheap).

As for non-succulents, aside from agave, only ever seen them on my bamboo.

Treated with some Sevin - that stuff is gooooood. Forget organic - I'm hooked on the big guns

DesertDweller - my A. utahensis v. nevadensis has mealys in the core just as you describe. I sprayed down in there as best as I could, but if that doesn't work I'm going with your Q-tip method.

Steph115 wrote:Treated with some Sevin - that stuff is gooooood. Forget organic - I'm hooked on the big guns

DesertDweller - my A. utahensis v. nevadensis has mealys in the core just as you describe. I sprayed down in there as best as I could, but if that doesn't work I'm going with your Q-tip method.

One thing I would add, just found this out recently. When you spray with things like Sevin, it doesn't seem to do much to wash the buggers out, just kills 'em and leaves a mess. I noticed that if you take some insecticidal soap to them later on, that seems to work better at breaking them loose and washing them off. Maybe because the stuff is so comparatively slippery? Not sure, but that has been my method of choice now to clean out the carcasses.

OK, I'm breaking out the big guns. I took Kent's advice and picked up a backpack sprayer. First impression is extremely positive -- this thing is awesome! We'll see how long it lasts, but is was only $65. The plan is to spray everything, plants, ground, rocks, you name it, with the termiticide, bifenthrin. Up to six month residual, and it doesn't kill immediately, giving pests time to move it around and introduce it to their friends. I know this seems very harsh, but my infestation now includes mealies, root mealies and scale, and they are killing my Agaves, even very large Agaves. I just don't see a foliar spray having much impact on root mealies. In a few weeks, I will follow up with a foliar spray of acetamiprid, a translaminar neonicotinoid insecticide primarily directed at exterminating sucking insects, including aphids and their kin. I'm hoping two rounds will end this nightmare.

Good luck Gee. That infestation sounds terrible - I can't believe it's starting to take a toll on your bigger agaves. I hope the big guns work for you.

I've had a good experience with Sevin, although DesertDweller is totally right about it leaving the carcasses. I keep seeing "mealys" and thinking that it hasn't worked, but then when I poke them they fall right off.

Just to add, I am finding it more prevalent this year than in previous ones, by a notable margin. I've not ever had this many plants that I had to douse, even if most are not that bad. They are quite pervasive this year, but I've not yet picked up a pattern. A couple plants side by side end up being attacked, but then nothing for a ways off, and then another random one here or there.

Oddly, I did notice they must not like the rough stuff. I have yet to see any real issue on anything scabrous (cerulata, asperrima, etc.). A few of them tried to take hold on one plant, but they seem to have just died somehow.

The Agave I first noticed with mealies was A. celulata, about 3-4 years ago. Since first spotted, I could knock 'em down easily enough, but they always return.

I've already noticed one benefit from my shock and awe campaign -- I found a dead gopher today, who apparently dragged himself out of his hole to die after spraying. I never had problems with gophers until construction began on two new homes across the street. The exodus of rodents from the construction site to my property was startling. I suspected gophers were in that mix, but never actually saw one before today.

As I continue to research this, I now realize there is no reliable way to defeat a major mealybug outbeak. There is all manner of method and chemical, but in the end it's a war of attrition fought with weaponry of limited effectiveness.

Seem to recall we've been over this before. Having controlled persistent outbreaks of mealies (incl root mealies) in commercial greenhouses that had been so overrun the owners were at wits end, strongly recommend Enstar II in combo with a contact (malathion or Mavrik) and spreader-sticker to runoff. Get a good rechargable electric backpack or hand towed sprayer. All-in for the above probably just over USD 350.00, but for situation you describe, a worthwhile investment. Two or three cycles should produce desired results.

This is not a pest that is difficult to control with the right products and spray regimen. Those claiming mealies and armored scale are "impossible" to gain control over simply don't know their ag-chem. Child's play when compared to pesticide resistent two spot spider or cyclamen mites.

I use Safari in rotation with imidacloprid drenches in my own collection in the US, since I never let them get out of hand. Have not needed to resort to any tool in the greenhouse heavier than a 1.5 lt hand sprayer in years, but am ever vigilant and on them at first sign of a colony. Once they're gone, do not let them regain even a toe hold. Seasonally, thrips and aphids much bigger threat for me since I primarily grow rare tropical foliage and orchids.

Always be aware of local laws governing pesticide use and employ common sense and proper safety gear when spraying.

Good hunting,

J

Thanks, I have a new backpack sprayer (a $65 hand pumper), and selected Bifen and the translaminar insecticide TriStar for my initial attack. I just finished spraying everything (ground, plants, everything....) with the termiticide, Bifen, and will follow up in a week or so with TriStar. Bifen has a residual of up to 6 months, so I thought that a good choice for root mealies. Oh, and I also have scale now.

I've had limited success with imidacloprid and found this article that suggests limited success with all systemics: Mealybugs and Systemic Insecticides

If my chems aren't up to the task, I'll pick up Enstar II. Should I spray everything with it as I did with Bifen, or just use as a foliar?

Cannot believe that Mealy Bugs are causing such a major problem. Over here, in my experience, they are more of an irritant. There is always a vague presence in the greenhouse, but seldom causes me any real problems. Outdoors, they are conspicuous by their absence, and that must be because of our wet and damp climate. Indoors with the warm room temperature, they tend to flourish, if you let them. I always move any plant affected outside, give them a vigorous water spray followed by some insecticide, and that generally solves the problem. Maybe I should pay more attention to these destructive pests considering your experience. Jkw

I have already commented on the linked article on the accompanying thread, so back to practical control.

There is little argument that drenches involving systemic pesticides made on dormant or semi-dormant plants can be of limited value. Since my experience with worst case scenarios involved commercial setups with Cattleya orchids and all the cycad genera, it was probably easier for me to onboard and digest this limitation than it would be for the average grower.

I do not use bifenthrin, but have colleagues who spray Talstar Pro (equivalent to Bifen) in the greenhouse I'm in as a broad spectrum contact/residual and are more or less happy with the results. I would emphasize that no one at my location is controlling a major outbreak of anything. My personal experience, based on a couple decades wrestling with mealies and Asian cycad scale as a hobbyist and outside consultant is that a successful eradication program starts with a good contact insecticide in combination with Enstar sprayed to runoff with complete coverage - hence the importance of a spray rig that provides ease of use and uniform nozzle pressure - at curative label rates. Minimum two apps. Further touch up control can be provided as needed. Follow up with Safari (Dinotefuran) in rotation with imidacloprid drenches as preventive.

While I understand that these products are not available to everyone, and that some may find the cost prohibitive, I think the end result is well worth it for growers with larger collections facing a major outbreak.

I cannot emphasize enough the need for subsequent vigilance to avoid scale, mealybugs, etc from re-establishing themselves in one's collection. Once wiped out, I find that having a hand sprayer around containing a fresh solution of your prefered contact insecticide (I find Bayer 3 in 1 Advanced is a good, low-tox option in this role) or home remedy bug elixir will usually do it.

We'll see where I'm at come spring. Winter is coming and the situation should calm down for a while as a result, and I'd guess the efficacy of my initial product choices will be plain to see come spring. I have yet to use TriStar (acetamiprid), but thought its translaminar qualities an upgrade from contact malathion -- we'll see. Unless best case scenario plays out, I'll pick up Enstar II come spring.

Gee, I'm sorry you're dealing with this headache but confident that you'll crack the code. You'll find the right combination of chems and the best spray frequency to break their cycle and send those mini tribbles packing. I lifted the A. americana v. protoamericana you sent and everything down below looks great to me. Are the root mealies obvious to the eye?

Very obvious!

They often have a pink coloration when underground.

The Monger

Azuleja wrote:Gee, I'm sorry you're dealing with this headache but confident that you'll crack the code. You'll find the right combination of chems and the best spray frequency to break their cycle and send those mini tribbles packing. I lifted the A. americana v. protoamericana you sent and everything down below looks great to me. Are the root mealies obvious to the eye?

Azul, don't sweat it. The little monsters have not yet made it close to that part of my yard. That plant was waaaaay in back, and they're sweeping in from the front. I'm not even spraying anywhere near where that pup came from.

Nice rootball! That sucker can see ground next spring. It's mama is gorgeous!

Stone Jaguar wrote:I have already commented on the linked article on the accompanying thread, so back to practical control.

There is little argument that drenches involving systemic pesticides made on dormant or semi-dormant plants can be of limited value. Since my experience with worst case scenarios involved commercial setups with Cattleya orchids and all the cycad genera, it was probably easier for me to onboard and digest this limitation than it would be for the average grower.

I do not use bifenthrin, but have colleagues who spray Talstar Pro (equivalent to Bifen) in the greenhouse I'm in as a broad spectrum contact/residual and are more or less happy with the results. I would emphasize that no one at my location is controlling a major outbreak of anything. My personal experience, based on a couple decades wrestling with mealies and Asian cycad scale as a hobbyist and outside consultant is that a successful eradication program starts with a good contact insecticide in combination with Enstar sprayed to runoff with complete coverage - hence the importance of a spray rig that provides ease of use and uniform nozzle pressure - at curative label rates. Minimum two apps. Further touch up control can be provided as needed. Follow up with Safari (Dinotefuran) in rotation with imidacloprid drenches as preventive.

While I understand that these products are not available to everyone, and that some may find the cost prohibitive, I think the end result is well worth it for growers with larger collections facing a major outbreak.

I cannot emphasize enough the need for subsequent vigilance to avoid scale, mealybugs, etc from re-establishing themselves in one's collection. Once wiped out, I find that having a hand sprayer around containing a fresh solution of your prefered contact insecticide (I find Bayer 3 in 1 Advanced is a good, low-tox option in this role) or home remedy bug elixir will usually do it.

Thanks for all the terrific info. Two final questions:

Do mealys attack shrubs like Eremophila, Lavandula and Caesalpinia? I sprayed the best I could but....

I just sprayed everything -- finished yesterday. How long would you wait before unleashing product 2 (my translaminar foliar spray)? Is next weekend too soon? I might wait a little longer, but winter is coming.

They certainly will infest Caesalpinia. From your description of the severity of the infestation, i.e. that you are actually losing plants, I would spray anything suspect. Dogbanes, asters, cucurbits, etc. all seem to be attractive hosts, so look over your garden carefully, particularly underneath yellowed or blotchy leaves.

Your neonic is Chipco in another pair of pants, so you should be safe to spray immediately. Personal bias; I don't like to mix as a general rule (Enstar excepted), but followup sprays of a separate chemical at 48-72 hrs has never given me any problems in terms of phytoxicity. Lots of people do make up tank mixes of different compatible insecticides, fungicides, etc to economize on effort and are successful doing so. It is my understanding that bifenthrin is quite safe to mix, but better safe than sorry. Just be sure not to double up on surfactants, since these may give you headaches on stem succulents if you are doing repetitive sprays for weeks, all with added surfactants.

Good luck,

Jay

Stone Jaguar wrote:They certainly will infest Caesalpinia.

I was hoping you wouldn't say that. I have a single C. pulcherrima and a C. mexicana hybrid of some manner. May as well have me treat a redwood tree as the pulcherrima, it is enormous. Good news is they both look healthy. Bad news is they're right in the thick of it and I'm sure the little boogers will look for any port in the storm once the pressure is on. The C. mexicana is manageable and I'll give it a good foliar dousing next week. The pulcherrima is another matter, but I can cut it nearly to the ground in a few weeks then treat what's left.

Have yet to add the second chem to the fight, as I still had about a gallon of Bifen left in the backpack sprayer, which I used to respray the center of the infestation, and specifically, two very large Agaves, thus difficult applications. Of three severely damaged Agaves, a gorgeous 5' tall A. palmeri is lost, a 5.5' tall A. sisalana's life still hangs in the balance, and an A. montana has clearly recovered, responding quickly to a malathion dousing two weeks prior.

Had an interesting experience this past weekend, as I believe some small dose of Bifen entered my bloodstream. I was cleaning up the downed A. palmeri, which I had sprayed the day before, and spines got me on the arm. Shortly thereafter, an unusual irritating, itching sensation developed around the punctured area, and persisted for several hours before diminishing. No harm done apparently, but it got my attention. Reminded me a bit of a bark scorpion sting.

Gee, like all of us I have had serious ”bites” from agave terminal spines on many occasions. I seem to recall stabbings by Agave pelona and several Guatemalan spp. were the worst. Not comparable to any scorpion stings I’ve experienced (three genera) but very itchy and persistent. No pesticides associated with these incidents, AFAIR. I have a friend who gets seriously blasted every time he’s stabbed, so some people may develop sensitivity to the chemical defenses of these plants.

Malathion is good for mealy control, bad for bees, fish, herps. I like using it, but smell freaks Joe Public out and makes it a no-no at home and shared greenhouse here.

J

Agaves draw blood on pretty much a daily basis around here. I have cuts, gouges and punctures all over my body almost constantly -- have had for years. You know I'm out in habitat all the time, right? I even have a kit for removing subcutaneous Agave spines, which includes a jeweler's lens and an exacto knife. Pull it out about twice per month, on average. This was from marginals, and a decidedly distinct and attention-getting sensation. And most scorpions stings are hardly worth mentioning. Bark scorpion stings, OTOH... I have little doubt this sensation was toxin-induced.