Biodiversity impacts
The negative impacts on biodiversity of wasps are very well studied in New Zealand. The research is also amongst the best of any invasive invertebrate in natural ecosystems from around the world.
Consequently, wasps are one of the best-known pests in New Zealand (Beggs 2001).
Most of the biodiversity research has been focused in the beech forests at the top of the South Island. However, there is also evidence of the negatives impacts of wasps from other native habitats. In semi-urban scrub and pasture habitats of the Hamilton area, Harris and Oliver (1993) found that wasps were responsible for 12 000–75 000 prey/ha/season. Gardner-Gee and Beggs (2012) recently showed that wasps were the most common visitors to the honeydew of kanuka trees in northern New Zealand, and suggested their abundance may have disrupted bird–honeydew associations.