OPINION: Fascinating world of region’s insects

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By Ines Stager

Little is known about invertebrates, the butterfly and moth fauna of the eastern South Island.

The value of insects, which form part of our wildlife ecology, is often overlooked, particularly in the urban environment. More often than not we notice insects that we consider a nuisance, such as flies, wasps, cockroaches, ants, mosquitoes – and then out comes the spray can!

However, many pest species are now becoming resistant to insecticides and this will have enormous consequences in the future.

Not all insects are pests though, beneficial insects pollinate plants, feed other wildlife, decompose our green waste and eat other insect pests. They have an absolutely vital function in terms of our ecology and even survival.

Ines Stager

Unfortunately, as a recent international study shows, 40% of insects species potentially face extinction. The obvious threats are climate change, habitat loss, and the ubiquitous and excessive use of synthetic chemicals such as insecticides.

It is only during the last two or three years that detailed surveys of invertebrates have been undertaken in South Canterbury: at Conway’s Bush, Woodbury, Oliver Dryland Reserve, near Cooper’s Creek, Ellery Dryland Reserve, near the Orari River, Arowhenua Bush, Temuka, Caroline Bay and Timaru Botanic Gardens.

These surveys, most of them undertaken by Brian Patrick, an entomologist based in Christchurch, provide us with an overview and clearly show the diversity of insects, particularly butterflies and moths.

Hopefully further surveys of other bush and shrubland remnants in our region can be undertaken, which will provide a baseline for further comparison. We don’t know what we are losing if we don’t know what we’ve got!

About 10 of our endemic moths have the ability to mimic lichen, such as the Izatha huttonii (pictured), camouflaged against Pertusaria celata, a grey lichen, which occurs in the Timaru Botanic Gardens.

Brian has helped to discover more than 200 species of moths and butterflies, adding to around 2000 species in 35 families in New Zealand.

Many of the specimens are held by the Otago Museum awaiting classification. Anyone who has spent time with Brian in the field will be aware of his infectious enthusiasm for the subject.

As a testament to that, 17 species of stoneflies, ground-beetles, moths, butterflies and caddisflies have been named after Brian and his family members, many of whom share a passion for the natural world.

To learn more about butterflies, moths and other insects in a local context, Brian will present an overview on Wednesday, June 5, 2019 at 7pm at the Waihi Lodge function centre in Geraldine. Everybody is welcome to come along.

Ines Stager is a landscape architect based in Geraldine, a board member of the Royal Forest & Bird Protection Society and a committee member of the local branch.