Gardenias with spider mites

[Shaolo]

Hello,
I have a couple of gardenias that are very important to me. Unfortunately they have been attacked by spider mites (diagnosed by local nursery). I did one treatment of malathion but wasn’t terribly ecstatic with it and swapped to talstar p. I’ve also added EB Stone Rhody food.

I have a couple of questions. How often should I spray the talstar? I know it’s going to take multiple applications but have no idea if I should spray every 3 days or 7.

The other question is about my leaves. They are still yellowing from the base. Is there anything else I should be doing?

 

[sorce]

Welcome to Crazy!

If the nursery that diagnosed it is the same place selling you the chemicals, I would instantly question the integrity of the person making these recommendations.

Sorce

 

[Shaolo]

Nursery did not offer to sell me anything until I asked. They are a great local nursery, well rated and offer Bonsai classes (which are currently on hold). With that said when I originally spoke to the owner over the phone and described the problem he recommended a number of fertilizers to try and never tried to sell me on any of them. Most of it was stuff I could make up on my own.

When I took the bonsai in he pointed out that the problem was spider mites and probably not my Miracle Gro plant food. Pointed out the bugs, their eggs, scat, etc. still didn’t try to sell me. While I was there I inquired about fertilizer and that’s when he pointed out several acidic ones that would be good for gardenias.

For the bugs he Recommended malathion or Neem oil. Said malathion would work faster than neem but either should work. I use Talstar around the house and have experience with that so I highly prefer to use it over the malathion. Question is how often should it be applied? I’ve done a lot of searching and found answers ranging from 3-8 days. Weather in Oregon has been pretty warm the last week. Everything I’ve read indicates spider mites have a faster lifecycle under that kind of heat. Hence the how often should I apply chemicals question.

 

[Leo in N E Illinois]

I can not emphasize this point strongly enough. You MUST read the labels. You have used 2 different insecticides. Unfortunately, you are trying to kill SPIDER MITES. which are NOT Insects, they are ARACHNIDS and can not be killed by most insecticides. You need a MITICIDE. There are very few insectides that kill spider mite. Go back and ask for a miticide. Don't take anyone's word. Stand there and read the label, all of the fold out pages of the label. It will list what pests it will kill. Don't buy it unless it lists spider mites, flat mite and 2 spotted mites. Then read the directions for how often to apply. Warm weather, more frequent, cold weather, less frequent. The information is on the fold out label. By law the target pests must be listed. If mites are not on the list, it will not kill them, no matter what the ill informed clerk says.

Sorry you wasted valuable time with insectides.

You want a Mode of Action group 21 miticide. The Talstar is a pyrethrin, totally ineffective on mites. Malathion is an organophosphate, and again won't harm a spider, or a mite. But it will do nerve damage to humans.

 

[Leo in N E Illinois]

I don't list chemicals because what is approved in my state, may or may not be available in your state.

In the "olden times" I used Pentac. I believe it is only available in a limited number of states.

If you can not find a MITICIDE, check

https://www.hummert.com/chemicals-insecticides/?count=30

 

[Shaolo]

Hi Leo,
I did read the labels for both. Extensively. Both list spider mites.

 

[Leo in N E Illinois]

Sorry, the on line labels did not mention spider mites.

In that case, with the Talstar, repeat spray as indicated by the weather. If weather is above 80 daytime, repeat at the shortest label interval, 3 days. If weather is cool, 60 F daytime highs, repeat at 7 days. Keep repeating until you see no sign of living mites, then spray one more time. You should be clean.

 

[Leo in N E Illinois]

Both the products you have are "older", pesticides. There has been significant resistance development across North America. West coast in particular has pyrethrin resistance in mites and other insects. Alternate between the two sprays. As the two are different mode of action.

 

[BobbyLane]

spider mites trending atm!

in the past ive just blasted them off my trees with a few jets of water, never to be seen again.

 

[Leo in N E Illinois]

If after 5 applications, you still have mites, I suggest you switch to a different miticide, from a different mode of action group. So group 21 would be good, don't try a different group 1, which is malathion. Don't reach for a group 3, which is your pyrethrin based chemistry.

 

[Shaolo]

Very useful info Leo.

I came in to comment after you mentioned the every 3 days for temps over 80. It's been 90-100 here this week. So I'll be suiting up to spray again today.

Question. Are you recommending alternate between the group 1 and 3? If so would that be group 1 on day 1, day 4 would be group 3, etc.? Or group 1 day 1, group 3 day 2, group 1 day 4, group 2 day 5, etc.?

I did look in to the Sultan miticide last night. But it's $150 a bottle. I'll spend anything to save these trees because they have special sentimental value. But wow, that is expensive.

 

[Leo in N E Illinois]

I am recommending day one, Talstar, day4, malathion, then wait the shortest interval from the Malathion label, which will probably be 3 or 5 days, so that would bring you to day 7, spray Talstar,

The interval on the label indicates the length of time of the residual activity of the spray. You wait until each period ends.

Talstar, a pyrethrin, breaks down quickly in direct sunlight. Malathion the breakdown is not quite as quick. So I expect the recommended interval will be different for the Malathion. You spray Talstar the last day of the Malathion interval.

Other key, it reapplication rate is short enough so that from the time the residual activity ends, the next dose comes before the mite or target insect has time for newly hatched eggs to mature and begin laying eggs. For mites that can be as little as 24 hours.

 

[Shaolo]

I've been following the prescribed spraying.

I went out tonight to spray and noticed that the really sick plant has a couple of dead branches. Images attached.

I've been trying to walk the fine line of enough water, not too much water. Can anyone offer any insight on why the branches would be dying? Could this be a watering issue? If so, how can I tell? Is this more likely to be a nutrient issue?

Any info offered would be extremely appreciated.

 

[Leo in N E Illinois]

I do not see a nutrient issue. I would not do any fertilizer until after you have eliminated the mites and have some new growth.

The dead and dying is most likely your spider mites. They can kill a tree. Over-watering can also give similar symptoms, but lets go with your mites issue as the cause, as you seem to be aware of your watering.

I suggest cleaning up the tree, remove dead flowers, remove dead leaves, remove yellowing leaves. Remove detritus from the surface of the soil. The dead leaves allow hiding places for mites to avoid the sprays. Cleaning up the tree, and removing leaves as they die, will help you get rid of the mites.

 

[Shaolo]

I want to pick up a Miticide in case this last round of spraying didn't do it. Any recommendations?

I was leaning towards Sultan, but already read about Forbid 4F, Avid, Kontos, etc.

 

[Leo in N E Illinois]

I am familiar with Avid, it is an abamectin formulation. This is mode of action group 6, different mode of action than the 2 previous pesticides you have tried. This makes it a good option. The chemical avermectin is a fermentation product of a Streptomyces bacteria. As such, it can come in "organic, OMRI" formulations and conventional formulations. I am not familiar with the other miticides, and would have to go on line and read the labels, just as you have been doing. Be sure to read the directions for use, and the protective equipment required list. The PPE required alone may guide you to which is better to use in your situation. Also make note of which Mode of Action group it belongs to, don't bother with a group 3 or a group 1, as you have already used pesticides from those groups.

And, it always bears repeating, be certain it lists "Mites" as a target pest. Best if "Mites" is the principal target pest.

So weigh PPE required (a clue to toxicity to humans), weight the Mode of Action group, consider application method (spray, fog, drench, etc) and price. For some the price can be staggering. Often high price per unit pesticides are very effective and used in low doses, but your collection is not a multi-acre farm, the smallest package may be enough to spray several acres, several time, hence the high price.

So there is a lot to consider. And you are the one that must make the choice. I do like Avid. But the others are probably pretty good too. Read their labels, before you buy.