Helping Monarchs

There are many people in NZ who love monarchs and want to see the numbers increase. But there are some important points to remember.

Monarchs are part of an ecosystem; they are part of the food chain. Everything in Nature has pests, predators and parasites. A basic understanding of ecology and biodiversity is so important.

Monocultures

After World War II, with the development of artificial fertilisers and the introduction of large-scale farming machinery, "monocultures" became popular. Before that time farmers typically rotated crops to preserve soil productivity. Farms became bigger and "more efficient". But this method of farming (monocultures - the cultivation of a single crop or organism) had a negative impact on biodiversity and the long-term future of agriculture and biodiversity. The increased demand for food led to the clearing of forests, grasslands, and wetlands to make way for agriculture.

Another example: some gardeners wanted to have "rose gardens" or large areas of sweet peas. Production was always about profit and people.

But today people are realising that monocultures are unhealthy. Monocultures significantly increase the risk of pest infestations, disease outbreaks and environmental damage due to the lack of biodiversity. And we're not only talking about farming... we're talking about home gardens as well. Popular terms today are sustainability, rewilding, reforestation. And sustainability is all about the triple bottom line: profit, people, and the planet.

Ecosystems

Let's use our wētā for an example of an ecosystem. Wētā are mostly vegetarian but may also eat insects. Wētā get eaten by tuatara. Tuatara get eaten by kāhu (harriers) and ruru (moreporks). And so on – this is an example of a food web.

Monarch butterflies are in fact pests of milkweed, as are aphids! Because we love "monarchs" so much it is only natural to want to see their numbers increase (or at least NOT decrease). Effective ways can be as simple as planting more milkweed (swan plant) and nectar sources.

Some people want to develop a more intensive relationship – and it is very important that this is done responsibly.

The milkweed community

Milkweed (swan plant) is not just for monarchs alone. In a milkweed community you will also find aphids, Aphidius colemani wasps, ladybirds, milkweed beetles, the swan plant seed bug, the swan plant flower moth, social wasps, tachinid flies and many other species interacting – all living in relative harmony in the wild. As soon as one species arrives, one of its foes arrives soon after. Only the healthiest survive. And that is the way Nature works: survival of the fittest.

All of these species can have diseases. Infectious diseases are caused by pathogens (including bacteria, fungi, protozoa and viruses). With monarchs you may have heard of black death, NPV (nuclear polyhedrosis virus) or Oe (Ophryocystis elektroscirrha). These diseases will limit the number of monarchs on a milkweed so that the milkweed has a higher chance of survival. The diseases are all a part of the natural cycle and only build up when there is overcrowding.

Note: When you are raising a large number of monarch butterflies it is much easier for an infection to spread.

Sometimes deformities are not due to a disease but physical circumstances. When a monarch ecloses without sufficient room for it to expand its wings, or it falls while eclosing and is unable to climb up to extend its wings down, the result can be a deformed butterfly. Without scientific intervention (lab, microscope etc) you cannot be absolutely certain as to the cause of the deformity. For the sake of the other butterflies and caterpillars it is important that a deformed or sick monarch is isolated as you do not want to spread any infection.

It is essential that they are not kept as pets. Monarchs are wild animals, and you are doing the species a disservice by keeping them. Contagions are invisible – it is so easy for them to spread.

So how can I "help" monarchs
As stated above, the easiest way is to have healthy host plants and nectar plants growing in your garden, and in different parts of your garden. A female monarch will be able to smell a milkweed from 2 km away and will come and lay eggs. If you have a number of milkweeds in your garden, male monarchs will hang around waiting for the females. Have healthy soil, and add mulch to protect the soil throughout the year. So long as you keep your plants lush and healthy you need do nothing more than enjoy their beauty.

Say no to pumpkin!

Do not feed monarch caterpillars anything besides milkweed (e.g. swan plant). In the past we have suggested that other vegetables in the cucurbit family are fine as food for hungry monarch caterpillars. While some of the butterflies may eclose and look perfect, there is no evidence as to the long-term biological effects. It could make monarchs more vulnerable to predators, for example. It is important that if you are going to be involved in raising more monarchs, that you do so responsibly and plan ahead. Yes, accidents do happen – ask any farmer!

Euthanasia

The recommended way of euthanasing a monarch butterfly is to put it into a container and put the container into the freezer. Within a few minutes they are dead, and you have reduced the likelihood of other monarchs being affected.

Hygiene

If you are raising a large number of monarch butterflies, to reduce the likelihood of diseases you need to have a high standard of hygiene. Dispose of spent milkweed stems, tissues etc responsibly. Use a bleach solution to clean rearing containers regularly – follow the manufacturer’s directions. And rinse everything well.

Remember also that pesticides like plug-in pest controls and flea collars on pets are insecticides and may well affect your monarch caterpillars.

Outdoor Plants

If you suspect that a swan plant may be carrying the disease, i.e. that monarchs have left a disease on the leaves and as a result monarch caterpillars are picking up the disease, you can disinfect the plant.  Do this in a cooler time of the day:  Use a 20% bleach solution and spray on the plant. Spray the undersides of the leaves as well. Leave it on for 20 minutes and then wash off.

You can also bleach eggs if you want to have a more hands-on relationship with your monarchs. Check out this video here. (and please follow our YouTube channel for more helpful tips).

Saving Seed

If you want to save seed to share - or to help us with our fundraising - these instructions will be useful.

Instructions for seed collection