Systemics for Aphids?

[DesertDweller]

[realized I put this in the wrong section originally, so re-posted here and deleted the original]

Hi all,

I appeal to the collective wisdom of this forum once more, as I am continuing to deal with an aphid problem. It was largely abated due to Imidacloprid granules that I had been watering in, coupled with our good weather up until recently, but the latest spike in temperatures have brought them out in force.

Plants that have been regularly dosed with what I thought was plenty of Imidacloprid are showing active pockets of the critters, and in some cases they are doing enough damage that I've had no recourse but to risk over-doing it by dosing them up strongly a second time. I see no ill effects on the plants, as of yet, but I am starting to consider the possibility that either this stuff doesn't work as well as I need it to, or they are becoming resistant over time.

Is there another systemic I can get in granule form that can be watered in and will work? I'm thinking perhaps a rotational program would give me more bang for the buck. If nothing else, maybe something else would kill them quicker? In this heat, I am watering almost daily unless overcast or on the off chance we have a forecast of rain. This may be contributing to the lessened effectiveness, I realize, but it's a no-win situation of sorts.

Trying to keep ahead of it before anything gets too badly chomped, but I'm already seeing more activity than I am comfortable with. I definitely can't spray anything in this heat, given the horrid leaf burn I've had in years past, so granules or at least something in liquid form that I can water in, would be ideal.

Any ideas for a readily available systemic that might help where Imidacloprid is letting me down?

[johnw]

You could be correct as greenhouse growers used to tell me both Orthene and Imidichloprid lost their effect on aphids after a few applications. You might be better off using a quick knock-down chem like Permethrim.

[DesertDweller]

You could be correct as greenhouse growers used to tell me both Orthene and Imidichloprid lost their effect on aphids after a few applications. You might be better off using a quick knock-down chem like Permethrim.

I think I saw some of that at a nursery I frequent on the weekends. I'll have to check tomorrow and see what's out there.

I assume there's not much harm in applying this stuff shortly after having applied imidacloprid? There's only one plant that is really in bad shape right now, the others I can afford to hang back and see if they need to be dosed with something else. Honestly it seems the aphids are dying on the other plants, so I'm not sure how they can be so voracious on B. oldhamii 'Hirose' but barely nipping the B. oldhamii right beside it. Even where the leaves touch, damage is 5x worse on 'Hirose'. Makes me mad, because it will be ugly until monsoon season is over, presuming the aphids don't kill it completely. I've probably lost any chance of getting new canes out of it too. Cannot believe how fast that progressed.

[DesertDweller]

As an update for anyone reading this, I ended up getting some Orthene / acephate .97 in granular form. Watered it in aggressively today with a dosage slightly above the minimum recommended for aphids. Ended up doing everything in one go, because there are some aphids on all of them and I want to wipe out any of them that became resistant to the Imidicloprid if possible, and keep them controlled until we get into monsoon.

Will post some updates to let folks know how it works, but fingers crossed that it kills 'em quick and new growth will replace the damage. I would post pics of the worst impacted plants, but I don't want to give folks nightmares.

[johnw]

Did the nursery tell you it was okay to apply systemic Orthene after having applied systemic Imidichloprid?????

[DesertDweller]

Did the nursery tell you it was okay to apply systemic Orthene after having applied systemic Imidichloprid?????

It's been enough time in between and enough continuing damage that I don't have a choice if I want the worst off plants to survive at all. I still may lose one or two whole plants even if this stuff wipes them out in the next few days. Given the choice to throw more chemicals at it or watch $1000s in bamboo plants literally be devoured in front of me, what option could I take? Orthene was $20 and probably a lifetime supply for my purposes. If it doesn't work or kills the plants, it's not really an issue seeing as how in another couple weeks they will be dead to the ground from aphids anyway. That's not an exaggeration either, my 'Hirose' and D. minor 'amoenus' were eaten virtually to the ground. It looks like winter top kill, there is literally nothing left.

Why certain other plants that got the same imidacloprid were seemingly protected, I have no idea. These are on opposite sides of the yard. On one side, it spread readily from sp. 'Hirose' to my nearby vanilla B. oldhamii. Then it stopped dead at the B. ventricosa, but started to attack the other B. ventricosa beside it. B. malingensis is a few feet from D. minor 'amoenus' but untouched. B. lako, same distance away, was also being devoured.

Either I got an extremely defective batch of imidacloprid the last time, when I first started to see activity and applied it per usual (which normally works like a charm) or the bastards have become resistant enough that they flared back up and kept on devouring. Either way, Orthene will do the trick or I'll find something else to grow. I've struggled with this problem since the first bamboo I planted. Indeed, the sp. 'Hirose' is actually sitting in a spot where my worst infestation of B. oldhamii took place and I actually had a nice 10' specimen die to the ground and never recover. After initial success in beating them back with imidacloprid, I had hoped it wouldn't be an issue, but having hit 118F already and as dry as it has been, the aphids are just out of control this year.

Again, not my preference to turn the soil into a toxic wasteland, nor the plant, but there's not much else I can do but watch it be devoured. Having spent so much time, energy and money to get the plants to where they are, to see them ruined almost overnight in the middle of shooting season, makes me want to cut them all to the ground and just grow something else. Nothing like investing a year of watering, fertilizer, mulching and watching it flourish only to have some damn aphids trash the whole thing. Pisses me off like you have no idea.

[DesertDweller]

Quick update - acephate seems to have done the trick. Had almost overnight, complete kill off of aphids on every single bamboo in the yard. I literally cannot find living aphids despite my best efforts. I am already spotting healthy, un-molested new leaves unfurling on most plants. On the worst off, I see no continuing damage and signs of recovery, but still waiting on a few to start growing out again.

Definitely going to try rotating in the future. Hopefully if I get another batch of imidacloprid in a month or two, it will work, as any resistant aphids should have been wiped out.

I am still not 100% convinced it was adaptation so much as a defective product. I literally had zero control while applying boatloads of this stuff on the worst plants. Had I not trusted the product to be working on all the plants equally, I might have noticed how bad it was getting out of hand on some of them, before it was this late in the game. As it stands, I'm sure there's going to be significant setback on quite a few of them now.

On a positive note, the acephate didn't seem to harm the plants at all, including the new shoots that are coming up. Fingers crossed that between wiping out the aphids and hitting them with some fertilizer once they get going again, I will be able to green everything back up in time for fall.

[johnw]

re: Imidichloprid

I assume you did a soil drench. In the past here the advice was to water well first, allow it to drain for an hour or so and then do a Imidi drench. To insure uptake we had to do two things:

First apply just enough water during the first 10 days to keep the plants happy but not enough to dilute the I. concentration in the soil by leaching. If the evaporation rate was low then no extra water was given.

Lastly if heavy rains were predicted pots would be moved under cover to avoid dilution or if in ground then a tarp pulled over the root area to avoid dilution via leaching. Auto-irrigation was shut off for 10 days and meagre hand-watering of pots was done.

Uptake was complete after 10 days. As I recall the recommendation was that this treatment would last 12 months.

I recall nurserymen treating huge numbers of pots and then downpours happening, washing away hundrds of dollars of product.

Did you spray or drench the Orthene?

BTW neither product is available here for home owner use and an outright Imidi ban is likely imminent.

[DesertDweller]

I actually use soil drench in both cases. Can't go spraying chemicals because of the wind and because most of it would end up going over the wall into the neighbor's yards. Much as I despise some of them, it probably isn't a good idea.

I have watered less after the application. In this heat, I have to water daily because they are dry as a bone the next morning, but the watering regimen has never been an impediment in the past, so I'm confused by the inconsistency this go around.

I hope they don't ban the stuff, but if there's another drench that works as well, I'm happy to switch. So far these are the only two drenchable systemics I found readily available.

As for duration, most of the stuff I've seen on various brands featuring imidacloprid have been about 8 weeks. When the stuff was working, I did have to re-apply a little bit further out than that, because you could tell the aphids were starting to show up again. I am sure watering heavily in these temperatures plays a role, but even in Spring where I could skip a few days between waterings, it seemed to wear off in a couple months.

re: Imidichloprid

I assume you did a soil drench. In the past here the advice was to water well first, allow it to drain for an hour or so and then do a Imidi drench. To insure uptake we had to do two things:

First apply just enough water during the first 10 days to keep the plants happy but not enough to dilute the I. concentration in the soil by leaching. If the evaporation rate was low then no extra water was given.

Lastly if heavy rains were predicted pots would be moved under cover to avoid dilution or if in ground then a tarp pulled over the root area to avoid dilution via leaching. Auto-irrigation was shut off for 10 days and meagre hand-watering of pots was done.

Uptake was complete after 10 days. As I recall the recommendation was that this treatment would last 12 months.

I recall nurserymen treating huge numbers of pots and then downpours happening, washing away hundrds of dollars of product.

Did you spray or drench the Orthene?

BTW neither product is available here for home owner use and an outright Imidi ban is likely imminent.

[DesertDweller]

So I wanted to give an update here, for those that might have sub'ed this thread or for anyone reading it down the road. After continuing to find insects after the acephate wore off, I started to wonder if, while I never found webs, perhaps my sap-sucking damage was the work of some kind of mite? It clearly wasn't the bamboo mite, but it seemed consistent with general spider mite damage (e.g. two-spotted, or similar). Additionally, while many of the mites in Arizona red buggers and these were yellow,they were small enough that I could believe they were mites.

So, deciding not to waste more time on insecticides, I switched to miticide. And no, not the cheap stuff either. I got my hands on Forbid 4F, which I am ashamed to say cost me more than some of my 15-gallon bamboo, quite a bit North of $200 for an 8 oz. bottle of concentrate.

I applied the stuff with a pump sprayer, on the extreme high side of the suggested dosage that Bayer gave me. I hit every boo in the yard, whether or not they'd ever shown severe damage. I drenched them all, then worked backwards and soaked them again. Leaves, culms, branches, everything. Go scorched earth or go home, right?

For those who haven't used it, this stuff is touted as extremely potent. Kills all stages and is locally systemic and translaminar, so you can get the bastards on the bottom of the leaf even if you only spray the top. Lots of folks have recommended it for eriophyid mites on agave, for example, as they hide deep within the core and most other products can't penetrate, nor do they eradicate all stages. Systemic residual is claimed to be 45 days.

End result? I cannot find a living probably-mite bug anywhere on my plants now. New growth everywhere that comes out completely clean. I've even had a few new shoots emerging after the others had aborted once the infestation took hold and had weakened the plants. Almost a month out now and I still don't see any bugs.

The best part is that I saw absolutely no adverse reaction on the plants. It was still close to 100F at the when I put this stuff on, albeit overcast. I had worried about leaf damage or burning, but nothing of the sort, on any plant, large or small.

I've replaced all the plants that were dead to the ground, plus added a few new additions in the interim. They all look clean and I expect them to stay as such, given the weather is turning. That said, I will most likely hit everything once more after the new arrivals have had a chance to recover from transplant (unless I see bugs sooner). That should keep me in the clear until winter. I only ever had this kind of damage in late spring or early summer, so I suspect if I can make it into cooler temps without another flare up, I'll be good.

I wish, sorely, that I had been pointed to this product sooner. Price be damned, the stuff works and works insanely well. Supposedly very difficult for mites to adapt to as well. I probably have a lifetime supply now, but if anyone else is having problems with spider mites in general, don't waste your time or lose plants like I did. Buy some Forbid and be done with it.

As an afterthought, I have been scoping out bamboo stands around town, mainly at various nurseries. Without fail, I have found identical damage to what I had on my plants. Desiccated leaves, no webbing and lots of ruined growth points and dying canes. I suspect our brutal summer heat and lackluster monsoon have greatly exacerbated the spider mite problems vs. prior years, because it is apparently wide spread. Strangely, folks down in Tucson don't seem to have this problem. I envy them!