whereas the closely related yellow admiral larva consumes the whole shell. Larvae go through five growth stages (called instars). For about 10 days they have a brown body with small white spots and fine hairs (setae). At about 2.5 mm they moult and during this stage develop a pale stripe along the body just above the legs. The setae start to develop spikes, usually two or more at this stage. At about 5 mm long they moult again and the pale longitudinal lines become more obvious. At about 10 mm they moult once more, and the setae develop more spikes. The last moult is at about 22 mm, from where caterpillars grow to about 36 mm before pupating into a roughly 20–mm pupa. It is difficult to tell red admiral and yellow admiral caterpillars apart: looking at the 4th and 6th body segments, the yellow admiral larva has a wider light coloured area than the red admiral. The pupa of the red admiral tends to be thinner and longer than that yellow admiral when compared side by side, but otherwise they are very difficult to distinguish. Adult red admirals occur most frequently during summer. They over-winter as adults, so can be seen on warm winter days. They are long lived, surviving up to six months in the summer, and perhaps nine months for those which overwinter. The adults feed on nectar from various plant species (native and introduced) and occasionally on seepage of sap. They are strong fliers, but their short flights when feeding and ovipositing are very erratic. Flights over water or mountain ranges are straight and fast, characteristic of a migrating butterfly, but no migration within New Zealand has been reported. See also Butterflies of New Zealand References External links New Zealand red admiral discussed on RadioNZ Critter of the Week, 1 July 2016 Vanessa (butterfly) Butterflies of Oceania Endemic fauna of New Zealand Butterflies of New Zealand Butterflies described in 1775 Taxa named by Johan Christian Fabricius Endemic insects of New Zealand