Second year using imidacloprid. Last year seemed pretty good, but this year my larger trees have almost as much CLM damage as if I had not used it.
Applied in beginning of June per Bayer package directions:
"4. Pour the mixture at the base of the tree.
5. Fill the bucket with an additional gallon of water and pour at the
base of the tree."

I'm starting to question the wisdom of the directions to pour the stuff in the place least likely to have feeder roots, i.e. at the base of the tree (which I take to mean right next to the trunk). What do y'all think? The fact that my smaller trees seem to have benefited more from the same application method lends credence to my feeder root theory, I think.

Thanks,
BC

Imidacloprid applied as a drench is only effective for smaller in-ground (up to 8ft high) and containerized trees. The amount of the active ingredient needed to protect larger trees exceeds what is allowed by law - .5lb per acre, per year.

Commercial nurseries protect their younger stock with soil applied applications of systemic neonicotinoids insecticides such as Imidacloprid but once the trees are placed into the grove and into production, they are applied as foliar sprays.

Bottom line is that as a drench, you cannot legally supply a mid much less a large citrus tree with enough of the active ingredient for the insecticide to be effective. I assure you that Bayer would not distribute a product that make it feasible for a consumer to do this. Bayer Advanced contains .235% Imidacloprid. Admire 2f, also manufactured by Bayer is the commercial grade Imidacloprid that you and I can get (or a generic equivalent) contains 21.4% Imidacloprid. For a small citrus tree (in-ground) the correct application rate of Admire 2f is:

≤ 3 feet tall: 0.05 fl. oz.(1.5ml) in 8oz water applied directly to soil-rootstock interface
3 to 5 feet tall: 0.1 fl. oz. (3ml) in 10oz water applied directly to soil-rootstock interface

For containerized citrus, the correct application rate of Admire 2f is:

0.75ml per cubic foot of container media mixed with enough water to distribute throughout the media but not so much that and drips from the bottom of the container.

Applied at the lower rate of 1.5ml of Admire 2f per 8oz of water, a drench of delivers .321ml of Imidacloprid. To deliver the same amount of active ingredient with the Bayer Advanced product, you'd need to drench the tree with over 48oz of the undiluted product.

You're going to have to look at applying Imidacloprid as a foliar spray to see favorable results on your larger trees. For foliar applications with Admire 2f, the correct mix is 16 to 32oz per acre or roughly 3mil per gallon of water. the use of an adjuvant will greatly improve it's effectiveness. Applied as a foliar spray it can take up to two weeks to obtain control that will last for 60 days or so. Make double, triple, extra sure that there is no Bee activity when and/or after you spray.

Best,

Skinn30a

Thanks for the excellent info, Skinn.

I also noticed a huge amount of CLM damage this year compared to last in the mature trees. I have a large number of small citrus in pots where I used Bayer Advanced at the recommended rate. I noticed mixed effects. Some trees seem to be protected well, with only a short CLM track with a dead larvae. Others seemed completely unprotected.

I realized the problem with Bayer Advanced and mature trees, when each would take at least the entire 32oz bottle. I was uncomfortable with that quantity since I really had to extrapolate off the chart for the product. I decided nothing was the prudent choice rather than doing it wrong.

I bought Dominion 2L, which is the only 21.4% Imidacloprid I could buy easily. I stopped when I wasn't sure that the method of application would be the same as Admire 2F. They are both the same concentration but Dominion is made for subterranean termites so I wasn't sure that the product would be absorbed into the tree.

Can you explain the "adjuvant" info in your post?

Does "foliar" always mean spraying the leaves of does that also include spraying the trunk/rootstock interface?

I would like to be prepared for next season for protection of my 7 mature trees plus some friends/neighbors that each have 2-4 mature trees and another friend that has 80 mature citrus uncomfortably close to the only confirmed HLB in Los Angeles County. I believe I killed a resting ACP in my backyard recently.

Adjuvant being a wetting agent/surficant that helps droplets of foliar applied solution (nutrients, pesticides, fungicides) spread out over the surface of the leaf and stay "wet" for a longer period of time thusly increasing coverage and absorption by the tree. There are lots of them out there... some folks use a 435 or similar light weight oil, Millet likes a product by the name of Tween 20, Hoosierquilt uses coco wet (I think), I use a product called Induce.... They all will greatly increase the effectiveness of whatever is applied as a foliar spray. Just makes sure that you're using the most appropriate one and the appropriate rate...435 oil for example should not be used if the temps are over 90 degrees...

Some of the best money I've ever spent (with the exception of that which procured my wife's wedding ring...;) was $100.00 on a 15gal Fimco Spot sprayer with a 35ft hose. I fill it up, put it in the back of my little truck, and roll tree to tree, this yard to the next. I've heard of some folks putting it on a hand truck or a children's wagon to move it onto places inaccessible to trucks or atvs. Do discerning leafs, twigs, trunks, with this thing - just point and spray. Warning once you use a battery powered sprayer you will not want to ever use much less clean a pump sprayer ever again.

Imidacloprid came off patent in 2006 and since there have been several products introduced to the market by manufacturers other than Bayer. I use and Admire 2f knockoff by the name of Mach 2.0 with excellent results. I buy a gallon of it from Triangle Chemical (they take phone orders and ship) for 49 bucks and if stored properly, it will last me from now until there is a superior alternative that won't mess with the bees (i'm not 100% sold that Imidacloprid does really mess with bees as much as folks say it does... That said, you have, have, have to use this product in a responsible manner because there are other folks out there way smarter than you and I that are convinces that the neonicotinoids are 86ing the bee population very quickly.

FYI - Imidacloprid is around more than a lot of folks realize. It is even found in the flea drops such as Advantage II and K9 Advantix II
that we put on our dogs cats which get touched a lot by other people including children. If the manufactures of such products know this and still put it out there at the concentration that they do (8.8% Imidacloprid or 0.32ml Imidacloprid per large dog) , I'm comfortable with the relative safety of applying it to my trees. That said, I still wear long sleeves, nitrile gloves, and glasses while mixing and applying Imidacloprid.

Best,

Skinn30a

Hi Skinn,

What about the rain like what we had this year. It rained nearly every day for two months. How much time do you need before a rain to allow for absorbtion?

Charles,

I do not know the answer to that question but assume that once the product dries, the tree can't absorb any more (Imidacloprid is a systemic so it is actually absorbed by the tree) hence the recommendation to mix with apply in conjunction with a adjuvant/surfactant. I apply my foliar application of Imidacloprid just as I to with foliar application of nutrients - between 2000 & 2200hrs and when about 2/3 of a new flush is hardened off - for me, this is not long after fruit set. The bees are on other flowers and the miners have not shown up yet.

That said, I will say that there is not an application method that would have been effective with the rain we got in July - we got 40 inches in 31 days.

Best,

Skinn30A

I believe that a typical ACP spray schedule for a commercial grove does include four applications of various systemic pesticides (among other things) through-out the year most of which are neonicotinoids (Imidacloprid, Acetamiprid, Clothianidin, & ‎Thiamethoxam). These are rotated to reduce the probability that ACP will become resistant to the chemicals.

That said, and in the case of Imidacloprid they are limited to two applications and/or 0.5 lbs of active ingredient (32oz of admire 2f (21.4%)) per acre per growing season regardless of application type (soil and/or foliar). This threshold was increased a year or so ago in light of ACP and greening.

My pesticide spray schedule that includes two applications of Imidacloprid, a couple sprays of oil, and one late summer shot of Spectricide's One and Done serves my purposes just fine... I do not have a single leaf miner track on any on my 19 citrus trees - most of which flushed 4 times this year.

Best,

Skinn30a

It seems the best way to fight CLM is to wash leafes with your own hand or to let trees to fight alone against it. CLM always somehow adopt to new pesticide.

Skinn - thanks for lots of great info, will take me a while to digest this, so I might have some more questions later.

What is the approximate timing of your spraying schedule?

Also, still stuck on the "base" thing for smaller trees - is this the same as "soil/rootstock interface", and are we talking right next to where the trunk enters the dirt, not between trunk and dripline as with most other things we want the roots to take up?

Thanks,
BC

Using it for in-ground trees is about useless. I use it for my container trees & it works great.

as all neonicotinoids kills bees. You shold not use it at all. In the European Union neonics are now banned.

Roberto,

I can imagine that the EU's position on neonicotinoids would soften a tad should greening ever make it across the pond. Applied appropriately, neonicotinoids are safe, effective, and have a very low negative impact on bees. That said, as will all pesticides that I'm aware of, there is the risk of unintended harm if the correct protocol for use is not adhered to.

I appreciate the bees and understand their importance in the grand scheme of things. I'm also 100% comfortable applying Imidacloprid to my trees as a foliar spray and drench. The only tree in my inventory that does not receive foliar sprays of the chemical is my meyer lemon - it blooms throughout the year and thusly receives it's medicine through it's roots.

Best,

Skinn30a

I recently treated my 25 or 30 citrus trees in pots with imidicloprid 21.4%. I used 1 teaspoon per 5 gallons of water. I then submerged each pot and saved the drippings as well. They have flushed out since then and not one leaf miner tunnel. I'm impressed.

I don't have any trees in the ground now here in my new house. That will have to wait until spring.

I intend to plant about a dozen satsuma trees in the ground and grow them to 4-5 feet tall. Then I'll topwork most of them to oranges or grapefruit. I've never lost a satsuma tree to cold since 1989, but I've had several grapefruit that size killed back to the stump. I'm thinking that getting some size on the orange trees by topworking will make them less likely to freeze. In the mean time I have all the varieties of oranges, lemons, and grapefruit I want to have eventually in pots so I'll have the budwood when I need it in a few years.