German wasp (vespula Germanica)
Wasps are a major problem in some beech forests where they consume massive amounts of honeydew. Honeydew is produced by a native scale insect and is an important food for native birds, bats, insects and lizards.
Wasps also eat huge numbers of native insects and have even been seen killing newly hatched birds. By eating so much, they upset the natural food chain of the forest.
Seasonally in some beech forests there are an estimated 12 nests, or 10,000 worker wasps, per hectare. This makes the total combined body-weight of wasps in these areas higher than the weight of all native birds, stoats and rodents, put together.
Sourced from: https://www.doc.govt.nz/nature/pests-and-threats/animal-pests/wasps/