Mites, tiny flies, etc.

[pokey1]

Hi! I have been noticing very tiny flies on several of my indoor cacti that are only noticeable when the plant is disturbed. Is there any sort of general insect killer that is safe? I have purchased Avid miticide, but have yet to need it, (knock wood). Can the Avid be used as a preventative, or only when infested? Thanks! P.S., I forgot to add that mealybugs nearly destroyed my 3 year old "fairy castle". Any preventative suggestions for those little devils? THANKS!

[iann]

Flies? Do they fly? Or not. Are they actually mites? Any webbing on the plants? Need to know before we can tell you what to do with (or to!) them. Although Avid will kill pretty much anything.

[cefalophone]

I use isopropyl alcohol diluted in water to deal with insects. I try to stay as organic as possible with my gardening. But that is just me.

[pokey1]

Yes, Iann, they definitely fly, and I have noticed no webbing or mites. Is it o.k. to use Avid as a preventative, (properly diluted, of course)? I like the idea of the isopropyl alcohol as well. I know Malathion is poular for mites and mealybugs, but again, are these used only on infestations, or can any of these be used to keep things from being attacked and eaten. Which insects are controlled by the alcohol, and what is the ratio? Are these sprayed directly on the cacti, just the soil, or both? Thanks so very much!!!!

[tudedude]

Could be fungus gnats eating away at fungus and algae growing in your plant soil. The worse case scenario is their larvae are eating your roots. Common for indoor plants due to low light and damp conditions.

[*Barracuda_52*]

Could be fungus gnats eating away at fungus and algae growing in your plant soil. The worse case scenario is their larvae are eating your roots. Common for indoor plants due to low light and damp conditions.

I agree fungus gnats, i know a few nurserys that use Avid in controling pests on there african violets and other plants for mainly mites and thrips, not sure what avid will do to a cactus, if you do use it you might want to go with it diluted as a test on only one cactus and wait and see if there is any reaction over a course of a week or so. But because the gnats larvae live down inside the soil you need to make sure the soil gets treated. Alot of folks get fungus gnats in there plants people use yellow sticky traps, some use jars with old fruit with celophane over the opening to the jar poked with a toothpick to make tiny holes the gnats can get in but not get back out hence also used for fruit fly problems, once theres enough in there just get rid of the jar and keep doing it till there under control. They dont like dry soil they preffer moist soil, some people try using small layer sand on the top of the soil mix as a deterant but i dont think that helps much. What ever anyone uses to kill funus gnats it has to get down into the soil to do any good as thats where all the larvae live.

[pokey1]

Thanks VERY much for the info.! I took a close look, and they are tiny and black in color. I just purchased the Avid, and would like to start a course as soon as possible to eliminate them before any major damage. I would like to know if it is o.k. to dilute the Avid with water, and use it to water them when it is time to. If this IS advisable, does anyone have any ideas on the ratio? I also read that some pesticides can be absorbed into the cactus itself, and aid in pest control. Thanks again to all you veteran cacti growers for your help!!!

[pokey1]

One more thing... I have just read that nematodes are good for this particular problem, (Steinernema feltiae, Hypoaspis miles). I checked on ordering some, and the minimum I saw to purchase is enough to cover 250 square feet. I only have about 40 pots. Any idea where to obtain smaller quantities? Thanks as always!

[tudedude]

Good thing about gnats is that you don't need to treat the cactus skin. Just add it to the water or whatever is recommended on the label and give the plant a nice watering. Try to avoid contacting the skin with the solution, water around the cactus. Try to vacuum up the flying gnats or they'll try and lay more eggs in the soil.

Some pesticides get absorbed into the skin. They're called systemic pesticides. Bayer makes some people here use a lot. Be warned that they are linked to the dying off of bee populations.

[greenknight]

One more thing... I have just read that nematodes are good for this particular problem, (Steinernema feltiae, Hypoaspis miles). I checked on ordering some, and the minimum I saw to purchase is enough to cover 250 square feet. I only have about 40 pots. Any idea where to obtain smaller quantities? Thanks as always!

The heavier you apply predatory nematodes, the faster the control will be. Don't worry about applying too much, it won't hurt anything.

[cefalophone]

Do places like home depot sell predatory mites? or is it a more specialized "product"

[Peterthecactusguy]

I dont know about home depot, but some landscaping catalogs have predatory mites, and nematodes for sale.

[Bruce]

One other thing to consider (if I can take this discussion sideways for a minute): I grow indoors and want to avoid introducing chemicals into my home. So, I mix in a few carnivorous plants (particularly pinguiculas) among my collection. While they're not much good for crawlers, they love fliers like fungus gnats. The occasional bloom of gnats gets quickly eliminated. (They're also fairly interesting themselves.)

[Peterthecactusguy]

Bruce, good idea. I have issues with fungus gnats sometimes. Three things work to get rid of them. 1. cinnamon, keeps the adults from landing in the soil. 2. a yellow piece of fly paper attracts the adults (haven't tried this one yet) and 3. hydrogen peroxide (mixed with water, which I think I do to a 5-1 ratio). I also have this issue in the now unused pool room at the ex's parents house. The gnats came from some garden plants where the soil wasn't nuked, and they came in and started annoying everything, anyways cinnamon was effective in the house where a few came in and got into some tropical cacti I had there. The H202 was effective at killing the larvae inside the soil and no new generations have been there. The pool room still has a few buzzing around. There are also a few fat and happy spiders that go nuts anytime I open a seedling tray lid and an adult flies out. so far no damage on the seedlings, I let them dry out and watered with H202 and almost all of the fungas gnats are gone now. They attacked my Pereskia so I have left them there, I don't want to bring them home and spread the infection. I watered them once with H202 and they have left them alone. No need for cinnamon at this point. Fungus gnats are annoying but their larvae can damage plant roots if they don't have enough rotting organic material to attack, which can kill seedlings and some plants (although rarely)

Best way to prevent these attacks? wet the soil and nuke it in a microwave to about 180F. Do not microwave dry soil and also measure carefully, at around 140F some of the eggs can survive and at over 200F it will make the soil lose it's nutrient value and kills the good stuff inside the soil..