What NOT to do

[butterfly mom]

I happily squirted diluted Dawn on the milkweed to kill the aphids. It worked on the aphids--for a while at least--but it also killed leaves on both the Swamp Milkweed and the Bloodflowers. So, it is back to donning disposable vinyl gloves and squishing the little monsters. (sigh)
... rita b

[texas butterfly]

Also, don't put baking soda and water on Tropical milkweed.
Did get rid of aphids, but also burnt the leaves.

My solution mix may have had too much baking soda.
A more diluted solution might work.

[Wyvern]

I happily squirted diluted Dawn on the milkweed to kill the aphids. It worked on the aphids--for a while at least--but it also killed leaves on both the Swamp Milkweed and the Bloodflowers. So, it is back to donning disposable vinyl gloves and squishing the little monsters. (sigh)
... rita b

Dawn and other dish soaps strip away protective oils and waxes. That is probably why the milkweed leaves died - they lost their protective moisture barrier.

[applestar]

This is a bit late, but for future reference -- I'm pretty sure Dawn is a detergent. Detergent, as you discovered is an effective herbicide (it's also bad for aquatic life). SOAP, however, will kill the aphids without killing the plants. I usually use Dr. Bronner's liquid soap -- generally peppermint since that's what I regularly buy, but using the "unscented baby mild" might be safest just in case the essential oils might harm or repel the cats. You can also use any unscented (like pure glycerin) bar soap -- shave with knife or box grater and dissolve. It doesn't take much. It's probably best to rinse the plant off well after "the deed is done"

[texas butterfly]

I wonder if just rinsing leaves with water might also work.

It seems after a rain the aphids get moved from milkweed.

[sbannister]

Rinsing works but they come back quicker - they come up from the soil, I think. Squishing works best for me, but i haven't tried the soap technique.

[summerluver]

I have Dr. Bonner's Castille Soap here that I dilute and use in my bathroom for hand washing. It doesn't irritate my skin and keeps it from getting too dried out. I currently have the almond flavor. Could I use this to spray for aphids next year, or are you referring to another type. Also, I was wondering if the spraying interferes with the beneficial insects, or allows our monarchs to lay eggs? I need a war plan for next year.

[applestar]

I think Almond will be OK. I mentioned unscented because most of the other Dr. Bronner's "flavors" -- Peppermint, Lavender, Eucalyptus, and Citrus (the last one is Rose, I believe) can be used effectively to repel one insect or another. I believe the soapy water suffocates them by blocking the spiracles (breathing holes). Have you seen this video? http://www.butterflyfunfacts.com/monarc ... -video.php

Soapy water is effective for killing almost any bug, including ants and flies. Most certainly, it could kill beneficial insects if they get caught in the spray. Part of my reluctance to spray aphids stems from concern that I might also end up spraying ladybug larvae. I only spray when there's a bad infestation and there are no ladybugs or larvae on or to put on the milkweed.

Soapy water also helps to make the aphids let go -- sometimes the aphids won't come off the plant unless you use water spray that is hard enough to also damage the leaves, but if you spray with soapy water first, then the water, they'll come off like a charm.

I don't know what effect the soap residue would have on the cats if they eat the leaves. I don't know for sure but soapy residue may not allow the eggs to stick properly.

[applestar]

Hm. I guess you can't edit your own posts here. I forgot to add the Tea Tree Oil among Dr. Bronner's "flavors." That one can also be used as repellent and antiseptic. Some reports of tea tree oil used as insecticide as well, so definitely don't want to use that one.

[Mona Miller]

You can edit, if you go back right away. You can "quote" and from that quote make an edit later. That's what I've been doing. Sometimes I go back and the link isn't working.

I find even organic pesticides can harm butterflies and other insects.