Caterpillars dine out on honeysuckle
A colony of hungry Japanese caterpillars is being held up as a cost-saving alternative to chemical sprays, to bring an invasive weed under control.
A total of 500 caterpillars have been released onto Japanese Honeysuckle growing near the Mangapiko Stream, Te Awamutu.
They will munch their way through the weed and grow into Honshu White Admiral butterflies, which will lay up to 200 eggs on neighbouring honeysuckles, to start the life cycle again.
The honeysuckle is an environmental weed because it blankets neighbouring vegetation as it climbs. It is prominent near streams and rivers.
Waikato
RiverCare released the caterpillars for the Waipa¯ District
Council at the stream recently.
Waikato
RiverCare operations manager
Kevin Hutchinson said it was not unusual for ‘‘bio control agents’’ like caterpillars to be used on weeds.
‘‘It’s being driven by people who want to switch from synthetic ag chemicals to a more natural approach. The bio agents provide a long term control measure because they’ve been selected specifically to target a particular variety of plant.’’
Hutchinson said in the long term, using the caterpillars to control the weed would come at a lower cost than traditional spraying methods.
‘‘Spraying weeds is not without consequence. Windy conditions could blow chemicals off target and on to other plants. Sometimes you have to clear other plants in order to reach the reserve where you need to spray’’.
There was a cost to buy the caterpillars which were reared at Manaaki Whenua Landcare Research in Lincoln, Canterbury.
‘‘I would say the costs were not cheap. But if you were to employ a person to spray weeds for example, the equivalent value of purchasing the caterpillars very quickly accounts for those (spraying) costs.
Waipa¯ District Council’s service delivery group manager, Dawn Inglis, said the council expected the butterflies to establish a viable colony in the Te Awamutu area over the next couple of years.