Contents > Butterflies > Resident > Monarch
Distribution & Status
Extensive Found in gardens nationwide up to 1,000 metres. There has even being sightings in Stewart Island in recent years, but there is no evidence of a breeding population on the island yet.
Scientific Classification More info
Allegedly self-introduced, the Maori name suggests it was seen before Europeans came to New Zealand, but it certainly was helped to establish by Europeans bringing Swan Plant for gardens. It was known that some people spread populations around the country. I suspect that it was introduced to both Australia and New Zealand at different times in the 1800's from California. This may explain why Monarchs don't migrate spectacularly like the eastern North American ones do. The larvae are preyed on by all Yellow and Black Wasps, (especially the Common (Vespula vulgaris) and Asian Paper (Polistes chinensis) wasps), Soldier Bugs and Praying Mantises. Occasionally Pteromalus Puparum (realised to control the White Butterfly) will infect fresh pupae. Known to chase off birds near breeding grounds. There isn't any recorded long-distance migration in New Zealand as there is in North America.Ovum In English
Generally laid on the underside of the leaves separately. Creamy colour when laid and deepening to yellow before hatching. It is cone-shaped with 20-25 vertical ribs. They hatch in about 5-7 days. The shell is eaten by the newly hatched larva for it's first meal.Larvae In English
Conspicuous Black, White and Yellow 'Tiger' stripes. Have 2 pairs of filaments, 1 pair at the front and 1 pair at the rear. The larvae live about 2-3 weeks and have 5 instars. Larvae are seeked by all wasps. Most Wasps are habitual in foraging, so if you have the foodplant in a pot, just moving the pot will delay the wasps in eating all the ovum and larvae, which they'll do once they found their source of food. They most actively feed by day, but also feed on warm nights. 3rd to 5th instar larvae will chew part-way through the stem of the leaf to let it droop, before starting to eat the leaf from the tip (or, more often, part-way down). This is to stop the plant 'bleeding' sticky sap and making feeding easier. They have no concept of social welfare as older larvae will happily munch their way through ovum and 1st instar larvae. They will also munch through a leaf or stem that holds a pupa, letting it drop to the ground (where it's unlikely to survive). Grows up to 50mm when fully grown.Pupa In English
Jade green with band of golden spots at head end. Hangs upside down by cremaster in some nearby sheltered spot. Pupation lasts between 1 and 3 weeks depending on air temp. However they will die if the temperature drops under 5°C.Imago In English
The imago has a 85 - 110mm wingspan, this depends an food supply for the larvae. it's everyday flight is a gentle gliding action, but if it feels threatened, then it can have strong, direct and sometimes rapid (up to 40km/h) flight. The American Monarchs are recorded as covering up to 100 kms per day on their migration flights. The male has narrow veins and androconial scales on the hindwings, while the female has thinker vein markings and no androconial scales on the hindwings. They take up to 4 hours to dry their wings on hatching. The imago lives about 2 months in the summer generation and up to 7 for the over-wintering generation. Autumn swarming usually appears to occur when the mean temperature drops below 10°C. This brings on the winter quiescence, where the imago is only seen in the middle of warm days drinking from flowers.Habitat
The Monarch is seen as a garden Butterfly in New Zealand, but can be found anywhere in New Zealand especially the warmer urban areas where lots of people grow it's foodplants mentioned below.Food Plants
it's main foodplants in New Zealand are Swan Plant (Gomphocarpus fruticosus), Giant Swan Plant (Asclepias physocarpus) and Tropical Milkweed - Bloodflower (Asclepias curassavica). In north America it's main foodplants are Butterfly weed (Asclepias tuberosa) - which is banned in NZ, Common Milkweed (Asclepias syriaca), Swamp Milkweed Asclepias incarnata and other members of the Milkweed family (Asclepias spp). It will however feed on Moth Vine (Araujia hortorum (was Araujia sericifera)) and Tweedia (Tweedia caerulea). It's rumoured that in it's final stage it will be able to eat ripe Pumpkin fruit (Cucurbita spp) and successfully complete metamorphosis, but people report varying results and deformities using Pumpkin. The larvae need to eat mainly Swan plant or Milkweed to successfully pupate, as this gives them the chemicals they need to have a successful metamorphosis.
Alternative foodplant information is on this page.