I use Imidacloprid. Its systemic and I water it into the soil twice a year. It kills most sucking insects but is not very effective against spider mites. Things like spiders and slugs may still decide to take up residence.

The best prevention is a healthy plant, healthy soil, and lots of fresh air and constant circulation.

Dry, stale air in the winter is what attracts pests indoors.

Pyola is effective against most harmful bugs, it is a mix of pyrethrin extract and canola oil, safe and biodegradeable.

Thanks for your input. I think I might try the neem oil treatment every ten days. I was also told that succs don't usually have problems outdoors. Any comments on that? Doing something twice a year wouldn't really fit my purposes, as my plants will only be out for a few months...they're just going to summer camp and then coming back home :) They're really just indoor plants but I want to give them a nice boost in the outdoors.

I put a few hundred plants out from May to October, and haven't lost any to insects, nor have I had damage from them (so far!). If you acquire a new plant with mealies, then you may want to use Imidacloprid to prevent others being affected. Larger collections inside, or in a greenhouse may need a preventative measure from time to time. Rabbits, kids, and thunderstorms are more of a concern outside.

Well the plants will be on a fifth floor balcony, so I can rule out kid or rabbit problems :-)
I will look up Imidacloprid...I've never heard of it. As a preventative (just because I don't want to deal with a bug problem in the first place) is the Imidacloprid better to use than the the Neem oil treatments (every ten days)?

I don't believe you should use anything as an insect preventative at this time. Sorry if I wasn't clear about that. Plants put outside have been healthier and grown better for me than those kept inside all year 'round. Neem Oil is less toxic than Imidacloprid (which is sold under a number of Commercial names, such as Bayer Tree and Shrub Care.) The neem oil can also be found under trade names; look at the ingredient list on the bottle. Still, I think good growing conditions are the best preventative for insects and disease, and a preventative spray will do little or nothing for you.

True...a preventative might not do anything per se, but it will keep my mind at ease, so it would do "something" for me, even if not for my plants :-)
I recently had my first bug problem (aphids) on a plant bought from a vendor that keeps his plant outdoors. All mine have been indoors their whole life and have never had bugs. So even if the Neem treatments (which I'm told is pretty harmless if done right) may not do anything....it actually will do something for me - SETTLE MY MIND :-)

I used some of the Imidicloprid on my 25 yr old Cephalocereus senilis that developed a bad case of the soil mealies, and I was loathe to part with something that I had had around for so long. It didn't seem to hurt it, and cleared up the bugs. But then I had the stuff, and decided to put some on a couple of African violets that were probably the source of the bugs. It was weird because they didn't seem affected except that their flowers were all washed out in color, and have remained so for a year and a half. So who knows what other affects could occur, and to what plants? I have a cute little cactus that I grew from seed that has its first buds ever after five years. I wouldn't like it to get bugs, but I would not like to wreck something that I worked hard on(not to mention what the plant thinks)just for "prevention" of a problem that doesn't exist. So I would be judicious with all chemicals, especially if I was not familiar with them. It's just a thought.

Barb

Thanks Barb. That's some valuable info, especially since I don't want to risk harming any hoya flowers. However, it sounds like Imidicloprid is a somewhat toxic chemical. Neem oil is organic or 'sort-of' organic, and I wouldn't even consider it a "chemical"...so I see what you're saying about using chemicals...I actually wanted to stay away from them, which is why I will try the neem oil (I am kind of set on "prevention" as you can see...it will make me feel more secure...I don't want any CHANCE of bringing bugs back into my house!). But thanks for letting me know the effects of the insectide on your flower coloring...IF I do get bugs, I'll know not to use any chemicals on my flowering plants. Thanks.

I actually found this on wisegeek.com:
Neem oil is a botanical pesticide made from an extract of the plant Azadirachta indica. Since it doesn't strongly affect humans, mammals, or beneficial bugs, farmers use neem oil as an insecticide and miticide to keep away pests like aphids and white flies. Neem oil even protects crops from fungal infections such as mildew and rust. People use insecticide with neem oil to repel mosquitoes and lice.

Azadirachtin-rich neem oil gets sprayed on crops as an organic substitute for other harsher insecticides that might be carcinogenic or have limited uses. Neem oil repels harmful insects like white flies, gnats, aphids, mites, and weevils, as well as strengthening the crops against rust, scab, mildew, and blight. Edible crops of vegetables do not get poisoned when neem oil is used.

Thanks everyone :)
Gabi

Its a dangerous, but fashionable, idea to imagine that "natural" and "organic" and "non-toxic" are all the same thing. Many natural substances are deathly poisonous, many man-made chemicals are not.

Using neem oil as an example, it has been shown to be essentially non-toxic insofar as causing short-term damage or disease, there is essntially no data on its longterm effects such as cancer and birth defects, it is simply assumed to be safe because it is "natural". Also you need to doubly careful of what your bottle of "neem" actually contains. Raw neem oil is a thick, solid in cool temperatures, goo which includes an actual insecticide Azadirachtine. Most "neem oil" products on the market are extracts which do not include significant quantities of this insecticide, they are mainly insect repellants, although as with most oils will smother any insect that is directly sprayed. You may find the repellant action desirable in your situation, the repellant chemicals are taken up systemically by some plants and so have a long-lasting effect.

It is doubly dangerous to imagine that "natural" substances are safe on plants. Any substance that you spray onto the leaves of a plant should be considered potentially harmful to the plant. NEVER just spray the whole plant with something you haven't used before. Spray some of the lower leaves first and see if they get damaged. Consider that any chemical applied to a plant will have some phytotoxic effect and keep the plant out of strong sun for a day or two. Be especially careful of plants with blue or grey surface blooms, these can be damaged even by water sprays and will never come back.

Imidacloprid as a soil drench is not harmful to any cactus, but it can produce phytotoxic effects, especially when used as a spray. Also check carefully what else might be in any insecticide that you use, there are often surfactants, oils, or soaps which can be damaging even when the insecticide itself is not. For example, the Imidacloprid formulation that I use (not available in the US) include sunflower oil, nice for smothering spider mites but definitely will damage sensitive succulents and definitely can have phytotoxic effects on succulents.

I once sprayed Neem oil on my haworthias, which were none the worse for it, but a few of the cacti and sansevierias I used it on were damaged. This was in spite of my carefully wiping off their leaves and keeping them out of direct sun for a few days. So test the Neem first, as Shrubs suggested.

Thanks Shrubs and also Biwako. I completely understand that 'organic' does not necessary mean safe. I would just choose something that was more organic rather than a chemical. For instance, with my recent aphid problem I used soapy water instead of insecticide, and it worked perfectly. The neem oil I am going to purchase has been highly recommended. It is Dyna-Gro, and it is 100% neem oil which has the Azadirachtin. I do know about keeping the plants out of the sun for a few days after treatment. Thank you for your advice on trying it out on the lower leaves first...I haven't thought of that. I will absolutely do that. And I will keep in mind that there is really no such thing as completely harmless, even if organic. I think I'll keep the Neem off of my succs though (I'll just put them on my hoyas and spiders), because I was told that succs/cacti aren't as susceptible to bug problems. And with what you just told me, Biwako, I don't want to take chances with my jade. Thanks.
Gabi