Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Superorder: Amphiesmenoptera
Order: Trichoptera
Common names: Sedge-flies, Rail-flies
The caddisflies are insects in the order of Trichoptera, with approximately 12,000 described species. They are small moth-like insects having two pairs of hairy membranous wings. They are closely related to Lepidoptera (moths and butterflies) which have scales on their wings, and the two orders together form the superorder Amphiesmenoptera. Caddisflies have aquatic larvae and are found in a wide variety of habitats such as streams, rivers, lakes, ponds, spring seeps, and temporary waters (vernal pools). The larvae of many species use silk to make protective cases of gravel, sand, twigs or other debris. The name "Trichoptera" comes from Greek: θρίξ (thrix, "hair") + πτερόν (pteron, "wing").
Photographed New Plymouth July
Photographed Wanaka, December.
This adult caddisfly of one of the net-spinning caddisflies Aoteapsyche/Hydropsyche. It's most likely either A. colonica or A. catherinae, both are common in Taranaki. 
This colourful caddis is in the genus Neurochorema. Since it was photographed in New Plymouth is either N. confusum or N. armstrongi. To distinguish between the two an expert would need to see the genitalia to confirm the species.
A long-horned caddisfly in the family of Leptoceridae
Other caddisflies below.
A caddisfly photographed December in Wanaka, Otago
Thanks to Wikipedia for text and information http://creativecommons.org/licenses/by-sa/3.0/
