Gracin Meyer Budge, of Balclutha School, asks :-
How did the first insects get to New Zealand?
Graham Wallis, an entomologist at Otago University, responded.
The first insects on the land mass that we now call New Zealand were already on it when we split away from Australia by continental drift some 80 million years ago. Many insects may have flown or been blown here more recently though. Some may even have arrived on vegetation drifting here from nearby islands during times of lower sea level. Many have more recently been brought here by humans.
Examples of the first type of insect include most or all of our weta, as well as many beetles and weevils. Although there are some similar animals in America, South Africa and Australia, New Zealand weta have probably been isolated since the Tasman Sea started to form. These types of animal are special because they do not have close relatives anywhere else in the world. It is important that we do our bit to look after them as part of the world's biodiversity.
An example of an insect that we know has recently (perhaps 100-150 years ago) dispersed from Australia is the Common Blue butterfly. This butterfly is commonly seen on introduced grasses and legumes found in pastures and roadsides in the summer. Unfortunately, this species is displacing our own Southern Blue butterfly, which prefers native broom, and is gradually losing out to the Australian invader as it spreads from the north. Other harmful crop and animal pest species continually threaten our shores, and are continually watched for in our ports.