Backyard Biodiversity: Making the most of Moth Week
Puriri moth (Aenetus virescens). Image: ShareAlike (CC BY-SA 2.0). Endemic to the North Island, the puriri moth has no mouth and cannot eat, instead they spend their short 48 hour lives trying to find a mate.
There’s something entrancing about a monarch or red admiral butterfly in flight, and you could bet that most Kiwis can name a few of our butterfly species. But what about the moths of Aotearoa?
International Moth Week is recognised annually during the last full week of July. It’s a celebration of the beauty, life cycles and habitats of moths and shows how they are so much more than just drab looking butterflies. For those of us that missed it this year, why not celebrate moths today?
Moths and butterflies share the classification order Lepidoptera — and they share many physical characteristics such as their delicate antennae and scaly wings. Yet moths are often overlooked, potentially because they are largely nocturnal or because they annoyingly flutter around our porch lights at night, unlike the more the more visibly vibrant butterflies.
But did you know that of the 2,000+ native lepidopteran species, only about 22 of these are butterflies? The rest are moths and over 90% of these are endemic – found in Aotearoa and nowhere else!
Plume moth (Pterophorus monospilalis). Image: Dougal Townsend (CC BY NC). Unlike most moths, the endemic white plume moth does not form a cocoon. Instead, they form a hard outer shell that is attached to the bottom of a leaf, much like a butterfly.
Moths live across the motu (land), from alpine peaks to coastal dunes, and play a crucial role in balancing these ecosystems. They work throughout the night pollinating flowers, some of which have nectar that can only be reached by their long proboscis and is inaccessible to bees. The adult and larval moths are also a major food source for native bats and some bird species.
Moths also act as valuable bio–indicators for environmental monitoring. With consideration to their relatively short life cycles and sensitivity to environmental changes, researchers can track changes in moth populations to gain insights into environmental conditions.
Despite their importance, the moths of Aotearoa, like many others around the world, face threats that have led to major population declines and extinctions. Many species have been impacted by habitat destruction from urbanisation, agriculture and forestry. This is exacerbated by the narrow range many species have of ‘host plants’, the plants that the caterpillar can consume (like the swan plant is to the monarch butterfly). Introduced predators like rats and stoats, further endanger moth populations. Climate change and light pollution also pose additional challenges to moths.
Male and female cinnabar moths (Tyria jacobaeae). Image: Mariusz401 (CC BY 3.0). The cinnabar moth was imported into New Zealand in 1926 as a form of biocontrol. The cinnabar caterpillars feed almost exclusively on ragwort, helping to eradicate this invasive and highly toxic plant.
What can you do to help our fuzzy, flying night-time navigators?
You can make a difference by planting a native garden
This will provide resources for both moths and butterflies, supporting their life cycles and ecological roles. Native plants like kawakawa, hīnau, and pūriri can offer much-needed sustenance. If you would like to attract certain moths to your garden, try to discover what plants they like most. For example, the spectacular pūriri moth’s caterpillars tunnel into the wood of pūriri, maire, mānuka and wineberry trees, and planting these in your garden may attract these large, green beauties.
You can turn off outdoor lights at night
By turning off outdoor lights at night, you can help moths better navigate their environment and be less distracted from their nightly pollination routine. Light pollution can significantly disrupt their natural behaviours.
You can participate in a citizen science project
You can participate in a citizen science project that helps monitor moth populations around New Zealand. Joining initiatives like MothNet or contributing data to platforms like iNaturalist can help researchers better understand and protect moth species, making an impact on conservation efforts.
You might have missed out on Moth Week this year, but moths can be celebrated every day. Without moths to pollinate them, many of our native plants would be at threat, and without moths to pray upon, our native bats and insectivore birds would have a much leaner diet.
