A pdf from Oregon State about plants that should grow well in your area..."Encouraging Beneficial Insects in Your Garden" (2001)

http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/38715/pnw550.pdf

That said, scouting your plants regularly is also a good tool. It's hard to catch everything and some seasons are worse than others, but finding small signs of infestations before they become too big can save a lot of headaches days/weeks later.

Some infestations can be managed with a simple pulling off of a leaf or a quick hosing off with water...it's nice to catch those early.

Here is a link that might be useful: Encouraging Beneficial Insects in Your Garden

same question w/ several responses at
http://forums.gardenweb.com/forums/load/pests/msg1122404112898.html?30969

Here is a link that might be useful: other thread, same question

Here's a decent chart.

Btw, Ladybugs are great, but green lacewings(the larvae) are even better.

The trick to an effective IPM program is to plant a wide diversity of flowering plants that bloom at different times throughout the year that not only ATTRACT the beneficials but keep them around repopulating AFTER they've feasted on the bad guys.

Kevin

Here is a link that might be useful: Beneficial plants and insects

Spraying broad spectrum poisons, such as the pyrethrins, will kill off the beneficial insects as well as pests.. Control of Aphids is fairly simple with just sharp sprays of water,
Attracting beneficial, predatory, insects to the garden starts with restraint in the use of poisons as well as making sure the soil in is a good healthy condition that will grow strong and healthy plants. Then providing a habitat that makes those insect feel wanted and provides shelter, food, and moisture.

Here is a link that might be useful: Attracting beneficial insects

This last season, aphids ravaged my pepper plants. I went through quite a bit of pyrethrins, but never completely got rid of them. Some plants were too far gone to save. Next season, I would like to attract aphid predators, like lady bugs, or anything else that kills aphids.

Stop killing the aphids. And plant something that will be "aphid bait" to get a good population built up before the garden gets going. Nothing attracts aphid predators except aphids.

Here's how it works ... ladybugs and lacewings and syrphid flies are attracted to plants with existing aphids. If they don't find enough aphids for their offspring to mature on, they look for different plants.

So when you see the first aphids, panic, and bring out the pesticides you not only kill off most of the aphids, you kill any baby ladybugs and lacewings you might have had or discourage the adults from laying eggs ... and you are stuck the rest of the year spraying poisons around the garden.

Wait and see what happens - I can have some plants encrusted with aphids early in the year and then see almost none the rest of the time as soon as the aphid predators come.

Syrphid fly adults are pollen eaters - if you plant some flat pollen source flowers (almost anything daisy-like will work) around the garden you encourage them. Lacewing and ladybug adults are bug-eaters, so you need to have aphids for them.

Are you saying to plant this "aphid bait" before planting the actual garden? And what if the predators still don't show up?

This is a type of "catch-22". Attract aphids so you can attract predators that will, in turn, destroy the aphids you already attracted. It might work, but I'm not doing it. Anyone else here try this?

Posted Today, 06:32 PM

Look. The aphids this season were not noticed by me until they were thick. Where the h--- were the predators if aphids attract predators?? Should I have waited even longer for the predatory insects to ride in on their white horse and save the day? I still say this is a gamble that most will not take. It might be great, but ONLY if the predatory insects show up to begin with, and show up IN TIME.

This post was edited by roguejim on Tue, Nov 18, 14 at 22:42

It does require keeping one's nerve when one first sees the aphids. I have learned over many years that when the black bean aphids show up I must wait until these guys show up..... and they do. Here they are having fun on the favas. You can see the left overs of an aphid snack there too. Ladybirds overwinter in hollow stems and debris so cleaning up the garden steriley in the Autumn does them no favours.

This is a type of "catch-22". Attract aphids so you can attract predators that will, in turn, destroy the aphids you already attracted. It might work, but I'm not doing it. Anyone else here try this?

OK ... then don't do it. But if you use chemical insecticides you will kill the predators as well as the aphids and have to keep spraying.

It is a bit of a paradox. What you will end up with is a low, sustainable aphid population held in check by the predators. After a couple of years you will have a population of over-wintering predators built up to reasonable levels and the initial population boom in the aphids is lower.

My ladybugs hibernate in the peeling bark of the mesquite trees. I don't know what the lacewings do. But every year, as soon as the brittlebrush and milkweed gets encrusted ... there they are.

Look. The aphids this season were not noticed by me until they were thick. Where the h--- were the predators if aphids attract predators?

Maybe they had no reason to visit your garden ... if you had been spraying chemical insecticides in previous years it takes time to switch to predatory insects.

Do you know what the eggs and larvae of syrphids, lacewings and ladybugs look like? And can you tell a dead aphid from a live one? You may have had eggs or larvae on the plants, but didn't see them or didn't know what they were.

Thanks for the further explanation. I will definitely reconsider. At present, I plan on buying beneficial insectary seeds, and planting them between my pepper rows. In the Fall, I've been mulching with a 4" layer of mulch. Maybe the lady bugs will over winter in the mulch?

Understanding the life cycle of Aphids and what causes them to appear can help in control. Control of insect pests starts with the soil the plants are growing in and good healthy soils, with balanced nutrients, grow plants that are less attractive to those insect pests.

Here is a link that might be useful: Controlling Aphids

Lots of flowers is the answer. Study in Michigan has shown that boneset and sweet alyssum are #1 and #2. Notice, lots of minute flowers; they attract the three families of minute wasps (1/20 to 1/50 inch) that do the best work. Regards, Peter.

Thank you Peter_6. I wonder how those particular minute flowers in our hot southern Oregon Summers. I'll look into it.

roguejim,
I can relate to you because I planted 12 artichokes this spring, spent early hours picking snails and slugs, finally protected them with coffee grounds, and when artichokes appeared, so did horrible black aphids :-(

And my daughter who lives in your country and loves artichokes was arriving so I was absolutely devastated and grabbed some pyrethrin made for mosquitoes and burnt the leaves of an artichoke :-( and then I was lucky because the sprayer ran out of pyrethrin.

And then ladybirds appeared out of nowhere and they were so numerous that it was disgusting to see so many of them !

And my daughter arrived, and she's a tree hugger like her old mom, and she was delighted to see such a mess of an organic garden, with so many ladybirds on the artichokes, she even tried to count them on a plant and honest she stopped at 50 ! And she did a minor in maths so yes she can count !

But I don't know whether it's the coffee or another parameter but the artichokes were so full of thorns that it was really a pain to eat them :-( So we ended admiring their purple flowers.

So give it a try, let nature reach a balance !

I've grown large numbers of peppers, both sweet and hot for years both indoors, in a greenhouse, and outside. Hot peppers are a passion, so I am continually starting new seedlings, and removing older plants. I've never used pesticides in any of my plantings, but have been tempted to on occasion. Generally once or twice a year I get a very heavy bloom of aphids on the peppers and several other plants I grow (especially the roses). For about a week the plants look terrible, covered with the aphids, some leaves falling, and honeydew dripping on the soil. Then the beneficial insects I introduced just one time come up to speed, and control the aphids. It is really amazing to see how quickly they cut the number of aphids, and what a thorough job they do. I have introduced parasitic wasps, green lacewings, and ladybugs. While all seem to maintain some presence in the plantings, it is the parasitic wasps that seem to do almost all the work. I plant a few plants to feed the beneficial insects some pollen, and provide shelter. My best plantings for this purpose are fennel, dill, alyssum, and cilantro. Since I can eat most of these plantings as well, they are not too much of a problem to maintain. Since it is the flowers that provide the most benefit, I allow all to flower freely; they all readily reseed in pots. I introduced the beneficial insects mostly about 16 years ago. Some other beneficial insects have joined the group over the years, particularly syrphid flies, some true bugs, and some predatory beetles. Together, these critters control all my bug issues. I have rarely lost a plant, and I grow quite a few hundred a year. It takes very few extra plants to keep the beneficials happy and fed. By the way, I find that the beneficials mostly stay where there is food, with the exception of ladybugs which will wander, even in the house.
Renais

Thanks for the advice, really. I'm writing down your list of beneficial plants. My peppers grow in raised beds. Would you advise I plant the beneficial plants in pots, and then set the pots in the raised beds, between the pepper rows, and around the perimeter? Or just plant them straight in the raised beds?

Seeing that you have a passion, you should pay a visit to The Hot Pepper forum. An international group of pepper enthusiasts (mostly U.S.).
http://thehotpepper.com/index/

Keep in mind that the beneficial and predator insects in any one area evolved with native plants, so planting non natives may not be what is needed even of they are quite attractive to those insects where the are native.
Also note in the article linked above where it says that excess Nitrogen makes plants more attractive to insect pests such as Aphids.

Thanks. I hadn't considered the "native" aspect of choosing the best plants. I think I will email the Oregon State University Extension service about what plants are native in my part of the State(southern Oregon).