Most likely these are fungus gnats, as aphids are rarely seen in the winged form. White flies are another problem that usually prefer warm climates for prolonged periods (like greenhouses) or homes. The adults of white flies are just as implied, they are all white and cannot be mistaken for much else. I have had problems with fungus gnats in the past while attempting to overwinter Pelargoniums or in my worm bins from loading them full of autumn leaves. The fungus gnats kinda look like Mosquitos, but are a different family all together.

Neem oil seems to be ineffective in my experiences with these critters. What has worked are the small yellow sticky cards that can be purchased at most greenhouses/nurseries. I bought 5 cards that are ready to be used from Paulino's for $5. The yellow color attracts the insects and the adults cannot avoid flying directly into the sticky card. You need to place the cards relatively near the plants and leave them for a little while, as the eggs they likely laid in the soil will hatch (if you plan to leave the plants indoors). These newly emerged insects will fly to the trap cards and you will shortly be done with this batch of them.

The fungus gnats feed on organic matter in the soil, leaving any topical treatment of neem or the like useless. Try watering the plants and see them fly, as the fungus gnats live in the soil. They will fly directly to the yellow cards. For the most part, these gnats are harmless, but my wife hates little insects flying about the house. To ease her concerns I deal with the gnats. I keep a worm bin in the house, in our basement, and often deal with fruit flies, fungus gnats, and other generally unappealing creepy crawlies (for most people) from time to time.

I hope this helps. I can post pics of cards if needed. The ones I purchased are similar to the link provided.

Here is a link that might be useful: Safer sticky cards

Oh ok, thanks. So just some sticky paper basically then? I've used sticky paper for flies before when I lived in Oklahoma, more flies there than one cares to mention. I'm assuming it's the same kind of thing, just yellow. I will definitely give it a try.

So, there's not really a way to kill the eggs then? And do these bugs hurt the plant??

If it really is fungus gnats (are they in the soil or on the plant parts?), if you let the surface dry enough they should go away all by themselves--and if you're keeping the surface wet enough all the time to have fungus gnats you're probably watering the plants more than they need anyway. I don't remember for sure, but I think there's a bt that will kill them in the soil, I'm thinking it might be the one that's in the mosquito "dunks" you can buy for ponds. I'm going incommunicado tomorrow for several days, so can't research it further for you, but google "mosquito dunks" along with "fungus gnats," or "bt" with "fungus gnats" and I think you'll get your answer. BUT letting the soil dry is easier and cheaper--and probably better for the plants.

Sorry to be so abrupt, but I really am "out of time" for now!

Skybird

This post was edited by skybird on Sat, May 17, 14 at 10:40

Yes, its the mosquito 'dunks' - you can buy granules. I use these routinely on all my potted seedlings and house plants - just sprinkle a teaspoon full on the soil surface. They're gone in a week or so. And stay away for years.

The gnat larvae do a number on those tiny root hairs, which is why I use it with seedlings. .

Here is a link that might be useful: from Amazon

Wow! Thanks for the info on the mosquito dunks stuff guys! Ya'll really are helpful and I appreciate it. I will give it a go.

As for the moist soil... I had purchased several plants from a specific gardening center, and the soil the plants were in came pre-gnatted, just for me! Joy! I do let all the plants dry out fully in between heavy drinks, after the near death on my purple basil.... Learned that lesson lol.

The nibbling of the roots was my main concern and why I want these buggers gone! I have a hard enough time not murdering my plants normally lol I don't need root nibblers roaming about, dang it. So I will definitely try out the stuff you guys mentioned.

Does that stuff work on white flies? I saw two tiny white looking flies the other day. I think there are less of those... but I think it's a different bug. UGH!

No, it won't work on white flies. They're a real problem to get rid of - and you want to get to work on them quickly.

Use those yellow sticky tapes, then research on the internet to find out what their small 'discs' look like on the undersides of leaves - then pluck the leaves and dispose of them.

I had a nasty infestation once, and I got so attuned to white flies that I could walk into the grocery store and spot one on a pile of lemons.

If they get into your house plants, you'll end up throwing out your house plants.

FGs are more a symptom of an underlying problem than they are a problem (for plants). Soil choice and watering habits are usually the underlying support for populations of the pests. Sometimes, a lighter hand on the watering can can solve the problem, unless the soil choice is rather inappropriate. On the other hand, it's difficult for populations to exist in those soils that have drainage/aeration sufficient to make it difficult to over-water.

Neem oil applications will work, but not in the sense that they will provide immediate knockdown. Then active ingredient in the right neem products (pure, cold-pressed neem oil) doesn't have to be ingested to be effective. Neem works in many ways. It is effective both in topical and a systemic applications. It is an anti-feedant, an oviposition deterrent (anti-egg laying), a growth inhibitor, a mating disrupter, and a chemosterilizer. Azadirachtin, a tetranortriterpenoid compound, closely mimics the hormone ecdysone, which is necessary for reproduction in insects. When present, it takes the place of the real hormone and thus disrupts not only the feeding process, but the metamorphic transition as well, disrupting molting. It interferes with the formation of chitin (insect "skin") and stops pupation in larvae, thus short-circuiting the insect life cycle. It also inhibits flight ability, helping stop insect spread geographically. You can see that its value for use against gnats lies in its ability to prevent future generations.

You can see more about neem oil by clicking the embedded link, but since the gnats are more an annoying symptom than a threat to plants, I'd look to that combination of soil choice and watering habits as the key to them moving their bothersome ways elsewhere.

Soils tend to be the root cause of more problems for container gardeners than the sum of all others. Even insects and disease are often symptoms of a plant weakened by a dysfunctional root system. I said that so I can say that gaining an understanding how water behaves in soils, and that relationship's impact on plant vitality, is probably the largest step forward a container gardener can make at any one time. I'll leave a link below to more info.

Al

Here is a link that might be useful: More about soils

LOL thanks Al, but I got your soil post last time, and thanks! It made sense to me, and I have been watering things way less. I actually only seem to notice the fungus gnats for a few days after I bring a new plant home from the nursery....so I'm thinking it's not actually my problem. I think they're dying out and should stay gone actually with my watering habits :) Thanks all who replied.

I read into the original post that the plants being brought into the house were coming in for only a few days. I thought you were bringing these plants in for only a day or two and then back outside. Sorry. The yellow cards work great for this application but perhaps you are looking for an indoor long term solution.

As for neem being used as a systemic, it is primarily effective against sucking insects (aphids, white flies, and their allies). What has not been mentioned thus far, is it takes at a minimum of 1 to 2 applications per week for at least 4 to 6 weeks for the compounds to be translocated into the phloem where sucking insects feed. That means if you started treating your plants now, by about July you might see some benefit for these groups of insects. I figured the plants would be back outside well before the neem would have any systemic effect.

As someone has pointed out, the active ingredient in neem can act as a molt inhibitor. The active ingredient breaks down rather quickly in the environment, within 4-8 hours, from oxidation and UV light. If the neem is not in uniform solution when applied, it will likely gather at the soil surface and break down from UV exposure. If these plants are to stay indoors, a regular treatment of neem couldn't hurt. However, if you are bringing these plants in only for a short time, I would avoid products that pushed adult fungus gnats from the infected plants onto house plants that will remain as house plants. In my experience, neem has not worked, though I unlikely treated for weeks on end as other means are more effective.

The mosquito dunks work great as well. Good suggestion. The mode of action of Bti is to lacerate the feeding tract of the insects. Natural and effective.

Of course as Skybird has suggested, letting the soil dry out between watering watering will help as well.

However, there's always someone out there to tell you to try making your own soil, as the available mixes are inadequate for growing plants due to poor drainage, thus the insect problem. It often starts something like this...first you have to find 8 different ingredients from likely 8 different stores that are not in the immediate vicinity. Then you have to make a soil filter to allow only particles of a certain size to sustain plant growth. Break out the knee pads and a tarp and mix it all together. Oh, and then there's practically no nutrients in the mix you made so you had better add some slow release fert. Don't forget to let the newly made mix sit for a few weeks to equilibrate and allow the pH to neutralize from the added lime. If you don't add a slow release fert then you had better get some N-P-K in there with each watering and don't forget the micronutrients.
What they forgot to tell you is it's so dry in the Front Range that you will have to water two or three times a day to keep up with transpiration and evaporation. These are the same people that will tell you, all the while residents of California and other western states are running out of drinking water, you should pour nutrient water into your pots until they drain 10 to 20 percent. All of this so that the precious feeder roots don't sit in overly moist conditions for a day or two. I tried it and in my climate and my unwillingness to slave over watering, it wasn't efficient nor effective.

It makes sense to me to allow the soil to dry between waterings and in cases where the insects are becoming more than a nuisance, choose an application to actively treat the fungus gnats that aligns with your overall level of commitment and desire to rid yourself of the fungus gnats. They are not a big deal in my opinion and reducing the population with sticky cards suits my needs.

I hope this helps a little to clarify the use of neem and provides some perspective on treatment options for the darn fungus gnats. I have attached a link that provides management options, though I note neem is not listed.

Here is a link that might be useful: Fungus gnats as household pests

GG - glad you feel you have things under control.

It's not surprising that someone would show up with remedial advice that pivots on the combination of soil choice and watering habits being the supportive mechanism that enables FG infestations ...... because in an overwhelming % of instances, that is in fact where the problem lies. See 'Container Gardening - Beginner's Class'. With the same surety advice will be offered suggesting that better aeration and drainage (a medium that doesn't remain soggy) will remedy the problem, someone who illustrates a lack of understanding of how soils work will be around to pooh pooh the soil advice, because "I tried it and it didn't work for me". Some soils, like the one you have to screen (gritty mix), are adjustable over a wide range for water retention w/o sacrificing aeration, just by varying the ratio of the ingredients - easy peasy, so to say the soil doesn't hold enough water is an indication that the person doesn't really understand how to apply the concept the soil is based on, or that there is some other agenda in play.

Also, if a grower is over-watering in the present, he can certainly afford to use a soil with better drainage and aeration. By doing so, the inappropriate watering habits would become appropriate, or at least much closer to appropriate, and the plants in the soil wouldn't be subject to the limitations others growing in water retentive soils are forced to accept.

I look at growing from the plant's perspective, what's best for the plant - not the grower or what's easiest. Most often, the two perspectives are mutually exclusive. And I always leave it to the grower to decide if the effort is worth the reward. I just provide reliable information. More than just a few thousand growers have decided that the effort of making their own soil is worth it. Many have discovered they really don't need to water as often as the alarmist's warnings claim. As I noted, in GGs case, he probably wouldn't need to water any more frequently than he already does if he was to adopt something like the 5:1:1 mix..

What you use for a soil isn't the important part. Understanding the relationship between soil structure and water retention, and how that relationship affects plant vitality IS. That understanding allows you to construct soils that work FOR you, instead of against you, and it empowers the grower to make solid decisions about how to balance that whole convenience: economics: plant vitality thing, a decision rightly made on an individual basis, not because Old Joe couldn't make something work.

BTW - I didn't say that neem oil would be my number 1 choice - not even pushing it as a good choice for FGs .... I said it WILL work - and it will. I use soils that are unfriendly to FG populations, so they haven't been a bother in a good long while.

Al

So many words. Many many words.

Sticky traps, bt dunks or granules, and let it dry. Works. But then we live here and have dealt with it.