No monarch butterfly eggs on my Swan Plants.

  • Creator
  • #47224

    Christine Willis

    My neighbour and I have at least 80 Swan Plants. My neighbour noticed that last year there were hardly any monarch butterfly eggs on the swan plants. The same thing is happening this year. We live on the East Coast of the North Island at Maketu. Temperate climate and a few monarchs flying around. But no eggs. Just wondered if 1) Is this happening elsewhere 2) What is the cause.
    My neighbour suspects that it may have something to do with the aerial spraying on the dairy farms and/or aerial spraying on the kiwifruit orchards.
    We would be interested in your response.
    Many thanks
    Christine Willis

Viewing 4 replies - 1 through 4 (of 4 total)
  • Author
  • #47412


    Hi there
    I too would like to report a complete lack of monarch caterpillars on my swan plants. There were a few butterflies around my garden earlier in the year, but it’s very unusual to have no caterpillars. I live on the Te Atatu Peninsula in Auckland. Everywhere I walk I look at swan plants. None of the plants I have seen, on the walkway in Te Atatu or in Paihia, where I was on holiday recently, had any caterpillars on them. I haven’t noticed wasps or other predators, particularly, but I wonder what is affecting the butterflies.
    Jane Gilmour



    Actually… I have hundreds of plants, lots of aphids and only found a few eggs – so i’m in a similar way to yourself. Hoping that some of the monarchs which are now being released will stick around and lay eggs.


    Christine Willis

    Hi Jacqui
    Thank you very much for your quick response. I was walking around in my neighbours garden yesterday and there were two (I’m assuming they are males), fluttering around. My neighbour has two plots of swan plants – the biggest plot which has at least 60 plants altogether (Plot A) – has no eggs. Although I noted that there were plenty of bright yellow aphids. The second plot perhaps 20 plants (Plot B), has 7 caterpillas and no aphids. No wasps though, they’re busy with the grapes.
    I will keep an eye on Neighbours and my swan plants to compare the differences.
    Also if there are people on your website wanting swan plants – I’m happy to give mine away – I have plenty.
    Will keep you updated Jacqui.



    About your plants: I know you say “a few monarchs flying around” but is that in your garden or in the general community, say between Maketu and SH2?

    Males tend to patrol the swan plants, fighting to keep other males out of their territory and hopeful that a female will come along. Females can be seen visiting the new growth on the plants, and you would see the ends of their abdomens curling around to lay their eggs under the leaves.

    If you haven’t seen this… yes that is unusual. Monarchs can smell milkweed (swan plants) from 2 km away. If you have seen monarchs around then it will be wasps or ants stealing the eggs and caterpillars.

    There are always pockets around the country where there are plenty of monarchs in all stages and other parts where there are none – meaning that the incidence of predators is high. Can you spend five minutes sitting in the sun in your garden, and watching the life around the plants?

    Nice place, Maketu!

Viewing 4 replies - 1 through 4 (of 4 total)

You must be logged in to reply to this topic.