Aphids versus monarch caterpillars

[ChachiJ]

Hi all, first time posting here, have 2 large monarch caterpillars munching on my milkweed, which is infested with the orange aphids (I saw some adult aphids brown with wings intermixed among the masses.) They are ALL OVER the area where the caterpillars are.
Questions I need answers to...

Will they harm the caterpillars or cause the caterpillars to stop eating?

How do I get rid of them without bothering the caterpillars?
The caterpillers are munching away on a leaf, and the stem to get to another leaf is covered by the aphids. I am concerned that either they will accidentally munch an aphid, get some bacterial problem and die, or they will not be able to get to another leaf and stop eating, or they'll fall off the stem because of those NASTY little aphids.

I thought about buying some lady bugs, but they can't get here in CT until Wednesday and it is getting really cold here. I don't know if ladybugs will last.

I apreciate any assistance, as these caterpillars are SO BIG, I know they are almost ready to go the next stage!!

[aphid]

Read the thread, "How can I get rid of the aphids w/out hurting the cats?" in this forum. I don't think aphids bother caterpillars, although I wonder if the ants that hang around the aphids might. I've read that there aren't any relationships between native ants and oleander aphids, but I've got a common milkweed that some ants march back and forth to the aphids. Of course, I could be mistaking what they are doing. Even if they were, I don't know that ants would find caterpillars a threat.

[harpo787]

Generally, I've seen ants do two things on milkweeds: "milk" aphids and also get moisture from flowers (which is very sweet from what I've tasted!).

Ladybugs work wonders with getting the aphids...but there are obvious things that can happen. They can simply leave the area and fly elsewhere, but usually they'll stick around if food is in abundance. However, I think the cold (unless it's FREEZING cold) might actually work to your advantage, as the cold will make them lethargic and less likely to leave. I know if you wish to keep ladybugs around for a few weeks you can keep them in the fridge.

Another thing to do is to contain the plant somehow and sprinkle some ladybugs on it, keeping it contained. Perhaps some sort of netting. I once used that netting over beds (the stuff that hangs from overhead) to keep them contained.

Another way is to just remove the cats from the plant and then to move in and attack. You can just squish the aphids, but your fingers will turn yellowish in color for a bit. You can also spray the plant/aphids down with a soap/water mixture. After a few hours, wash it down and most of the aphids should fall off and you should be able to put cats right back on. Be sure to wash thoroughly.

As far as I know, aphids will not attack the cats at all. If a cat is unable to get to another part of the plant to feed, it would probably just "let go" and fall to the ground and it MIGHT get back on the same plant, or else it may try to find another one (very tough unless you've got a patch going on).

Them aphids are hell I tell ya!

[Barbara Bishop]

.. Neem oil is a wonderful organic spray which does not seem to harm the caterpillars in any way..but the aphids hate it!!