Floating Row covers early one will help, but later insecticidal soap sprays can be effective as well as Neem Oil and pyrethrin sprays and dusts.
Many places suggest that leaf litter and garden debris are nice comfortable overwintering spas for them, but that same litter also harbors the predators of these pests, creates the environment that will allow nature to do what nature does provide a balanced environment.

wow! i live in new jersey, and my four-lined plant bug experience began two or three years ago. here, they attack my chrysanthemums, montauk daisies, peonies, japanese anemones and many other plants, creating an array of sunken brown spots. if the infestation is bad, the new growth is deformed.

i don't believe insecticidal soap is the answer -- that works primarily on soft-bodied insects like aphids. so far, i've cut the affected foliage off in late spring and the plants seem to rebound, since the lifespan of the adults is just about over by then. the pesticide applicator who sprays my evergreens (for bagworm) suggested a pyrethrin-based spray. i'm going to try that next year.

ps - i wonder if this is a sign that pests and moving north with warmer temperatures. i NEVER saw this bug before the past few seasons.

Insecticidal soap is a contact pesticide, it must contact the target insect to be effective and, the reason it is prefered by many organic gardeners, it has no residual affect. Once dry it is ineffective as a pesticide.
Since a sharp spray of water is all that is really necessary to control aphids even insecticidal soap is overkill for them.

kimmsr-
no arguement on how to treat aphids. sometimes i spray with a jet of water, sometimes i just wait until the lady bugs show up.
but it's misleading to suggest that insecticidal soap will work on hard-shelled beetles like four-lined plant bugs. it doesn't, even if you "contact" them.

i hesitate to use pyrethrins because of their effects on beneficials, and my fears for the butterflies, bees, dragonflies and hummingbirds. i may try it on a very limited basis if my "cut it off" policy doesn't control what is becoming a very serious infestation.

Insecticidal soaps are effective for hard shelled beetles so due care when applying them is necesary because they have reduced populations of Lady Beetles and insecticidal soaps are relatively effective at controlling Japanese Beetles.
That the Insecticidal soaps are most effective when used on soft bodied insects does not mean they are not at all effective against hard bodied insects. As always you identify the insect, first, determine if that insect needs some control and if it does start with the least toxic mean of control available, often Insecticdal Soap.

I have not seen that the addition of Horticultural oils do anything except render the insecticidal soap ineffective. Many people, apparently your information source, simply do not understand that insecticidal soaps must make direct contact with the target and once the solution is dry it has no affect, which is why sources such as your site say that soaps are inneffective against hard bodied insects. Like any other insecticide, insecticidal soaps must be used with due care, and only the target insect is to be sprayed with it, never, ever spray any insect control around randomly.
Web sites such as you quote often have a good reason to disparage good pest controls.

I find insecticidal soap effective in killing the four lined bug or a quick squish. But they are so fast that it can be difficult getting the spray on them. Mine are red in the young stage and eventually turn to a green/yellow/black flying beetle. I have spent hours in spring and summer patrolling my yard for these defacers of my property. I too found them a few years ago. I have read they make slits in perennial stalks and lay their eggs so I cut back many infected plants in fall and threw it in my brush pile. I had less damage this year but still many bugs. What I really should do is throw all of the cuttings in the garbage but I don't throw organic matter away. So I might shred it and hot compost it. And I will continue to fight them...

Get facts. So easy on the internet.

My favorite source of information is the Missouri Botanical Garden's Kemper Center:

http://www.mobot.org/gardeninghelp/plantfinder/IPM.asp?code=123&group=54&level=s

They recommend non-chemical responses first like cleaning up at year end or planting trap plants to lure the bugs away, but if you want to kill the nymphs and adults this year, start with insecticidal soap. Followed by more chemicals if needed.

I rarely use them at all, but if I have to I only use insecticides as a single spot treatment although I have a shelf full of stuff from former years. One thing I will kill immediately with chemicals is bagworms, and I treat container plants differently than garden plants. One year bagworms got all over 2 beautiful River Birch's, some 15 ft Viburnums and my 25 yr old Harry Lauders Walking Stick. Couldn't let that continue - heh heh.

I searched several Extension Service bulletins about Four Lined Bug to see just when they lay the eggs but none of them say - just says 'fall'. I would have no problem cutting down everything right now if it would eliminate the bugs, but since I'm not sure when the eggs get laid I will be cutting stuff to the ground and throwing away the debris in bags probably in early September. The hardest hit plants in my garden were the geraniums and also they just decimated my Brunnera Looking Glass - and once they got holes started something else has moved in - either earwigs or slugs - I've never seen what it is but they are full of holes.

kimpa - I compost everything but it's not worth it if the eggs overwinter - I found out the hard way it's ok to toss a few things out just to keep the garden clean and disease free.
I had a foliar virus overwinter in my compost pile from composting diseased foliage and then I spread it all over my gardens. I have malformed, curling leaves on everything from lilacs to rudbeckia to lilies. This year I've spent hours going over more than 1 acre of gardens removing distorted leaves and bagging them for the trash so it doesn't fall on the ground and contaminate the soil even worse. I am using Messenger and more fertilizer this year to improve plant health so they can fight off any infections. I can't believe this happened to me but I learned the hard way to keep diseased foliage out of my compost. I even let one compost bin dry out completely and then sprayed it with bleach to make sure I wasn't going to carry more of that stuff around the garden.

Anyway, I hope none of you get this nasty Four Lined Bug as bad as I did this year - it was pretty ugly through June. Although by now all the geranium foliage has completely regrown and you can't tell. The bed where it was the worst is going to be completely cleaned this fall and I'll lay some mulch or leaves on it for extra cover thru the winter.

Get facts. So easy on the internet.

My favorite source of information is the Missouri Botanical Garden's Kemper Center:

http://www.mobot.org/gardeninghelp/plantfinder/IPM.asp?code=123&group=54&level=s

They recommend non-chemical responses first like cleaning up at year end or planting trap plants to lure the bugs away, but if you want to kill the nymphs and adults this year, start with insecticidal soap. Followed by more chemicals if needed.

I rarely use them at all, but if I have to I only use insecticides as a single spot treatment although I have a shelf full of stuff from former years. One thing I will kill immediately with chemicals is bagworms, and I treat container plants differently than garden plants. One year bagworms got all over 2 beautiful River Birch's, some 15 ft Viburnums and my 25 yr old Harry Lauders Walking Stick. Couldn't let that continue - heh heh.

I searched several Extension Service bulletins about Four Lined Bug to see just when they lay the eggs but none of them say - just says 'fall'. I would have no problem cutting down everything right now if it would eliminate the bugs, but since I'm not sure when the eggs get laid I will be cutting stuff to the ground and throwing away the debris in bags probably in early September. The hardest hit plants in my garden were the geraniums and also they just decimated my Brunnera Looking Glass - and once they got holes started something else has moved in - either earwigs or slugs - I've never seen what it is but they are full of holes.

kimpa - I compost everything but it's not worth it if the eggs overwinter - I found out the hard way it's ok to toss a few things out just to keep the garden clean and disease free.
I had a foliar virus overwinter in my compost pile from composting diseased foliage and then I spread it all over my gardens. I have malformed, curling leaves on everything from lilacs to rudbeckia to lilies. This year I've spent hours going over more than 1 acre of gardens removing distorted leaves and bagging them for the trash so it doesn't fall on the ground and contaminate the soil even worse. I am using Messenger and more fertilizer this year to improve plant health so they can fight off any infections. I can't believe this happened to me but I learned the hard way to keep diseased foliage out of my compost. I even let one compost bin dry out completely and then sprayed it with bleach to make sure I wasn't going to carry more of that stuff around the garden.

Anyway, I hope none of you get this nasty Four Lined Bug as bad as I did this year - it was pretty ugly through June. Although by now all the geranium foliage has completely regrown and you can't tell. The bed where it was the worst is going to be completely cleaned this fall and I'll lay some mulch or leaves on it for extra cover thru the winter.

For years I've had problems with four-lined bugs (and they really are technically bugs, since they pierce and suck, not chew the way beetles do). I've been told by extension service people that they are more susceptible to things like rotenone when they are young and small, at which time they are round and red. You have to look carefully for them as they are hard to spot. I've tried all kinds of non-chemical treatments without luck. Today I used a product called EcoSmart Organic Insecticide, advertised to work on ants and roaches. Active ingredients are rosemary oil and cinnamon oil. I sprayed many of my plants with the oil a few hours ago and I just checked them again moments ago. Plants I had sprayed had almost no bugs. Other plants had lots of them. I removed a bug, placed it on my brick walkway and sprayed it. It walked slowly for a minute, stopped, rolled over, kicked its feet and then died. I believe I may have found a solution, and a relatively safe one at that. I'll be back to Home Depot soon to get a few more cans as I have a veritable herd of these little suckers (and I mean suckers literally).

Lee
What did the Ext Service tell you about what that spray does to flying insects and bees?
I have many blooming plants that are being affected but I don't want to spray over the flowers

Keep in mind people that Integrated Pest Management is not about going out and finding the most potent insecticide to sray anytime you see an insect, but it is about doing things that can help control insect pests without using harmful poisons in our environment.
If you have repeated problems with insect pests the soil the affected plants are growing in needs to be looked at closely because plants growing in good, healthy soil that are strong and healthy wil be less susceptible to insect pest and plant diseases.

Regarding my use of EcoSmart Organic Insecticide, I did not check with the extension service about it so I don't know what else it might affect. I do know that now that it has been a few days since I sprayed that it really has seemed to work. I can't imagine there are any insecticides so specific that they will affect nothing else other than your intended target. I do think that this spray's active ingredients of rosemary and cinnamon oils must be less toxic than most. I raise butterflies and moths and have host plants in my garden so I try to be very careful with what I use. The Ecospray appears to me through observation to be a contact spray so you have to get it on the bug, not just on the plant. With careful application you should be able to avoid or minimize side effects. The EPA lists the oils as minimum risk. I intend to buy the oils in concentrated form and mix them myself with water and a little ivory soap to use as a surfactant. Then I can use a pump spray rather than an aerosol. Here's a link to the manufacturer's website to learn more about the product: http://www.ecosmart.com/products/ant-and-roach-killer/