The New Zealand glow-worm is one of the most interesting insects of the New Zealand fauna. It occurs throughout the country in limestone caves, unused mining tunnels, along stream banks, in damp bush-clad ravines, in damp shady crevices, and under tree-fern fronds in rain forests.
The larva prepares a nest in the form of a tunnel of mucous and silk, and suspends from this an array of fishing lines composed of the same materials. Prey is snared in the long sticky fishing lines. The larva hauls up the fishing line on which the prey is entangled and consumes the trapped insect. Fully grown larvae measure up to 40 mm in length and adult flies average 15 mm in length.
During the early 1900’s Kakahi was essentially a sawmilling township and was supported by the two sawmills of the Railways Department which were situated there. The Railways Department employed 130 people from a population of 600 in the two mills. (At the 2006 Census there was a population of 132). Kakahi Township consisted of two boarding houses, two stores, butcher, baker, billiard saloon, public hall, school and church. The houses and whares of the mill hands were scattered around the mills and completed the settlement; the mills on one side of the river, the township on the other and were all dominated by the railway bridge.
The pumice cutting (now Te Rena Road) was originally dug for a proposed Kakahi-Pukawa (south-western shores of Lake Taupo) railway. The railway was to exploit the timber of Lake Taupo’s Western forests and open up the southern lake area, which had, at the time, no easy transport connections with the outside world. The long term plan was for this railway to connect with Taupo and Rotorua.
Kakahi derives its name from the Kakahi fresh water shellfish which may be found in the area. There are now extensive colonies of glow-worms which live all along the sheer banks where Te Rena road cuts deeply through the hill side for about 500 metres.