[Egilbert]

Hi – Are the swan plants poisonous to the caterpillars at any stage??

We bought our second lot of plants from Kings Plant Barn (St Lukes, Auckland), and the day after we brought our second lot home we had over 60 writhing and dying caterpillars on our hands (see previous post). We took them back to Kings Plant Barn, and the manager was adamant, “hand on heart” that there was no way insecticide had come into contact with the plants.
He said “we’ve had this before, just google it, the plants, at a certain, early stage of their lives, are actually poisonous to the caterpillar; that it was our fault for transplanting the caterpillars over ourselves (which we had done with the first lot of plants we bought from them only 1 week before hand and had NO issues with dying caterpillars whatsoever), and barely a sorry that this happened.

Suffice to say, despite spraying these plants down with water, and nearly three week weeks later, and STILL no sign of eggs, caterpillars, or butterflies even TOUCHING these plants (but laying on plants in close vicinity).

What gives?? Is he right??

[Jacqui]

Hi Egilbert – it can be that there is an imbalance of glycosides in one milkweed plant to another and therefore the caterpillars can poison themselves. We have written about this before on our website:

Plants

I don’t think I’ve seen your “previous post” so will look for more detail about what you have said.

Jacqui

[Author]

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