New Zealand

Asian Paper Wasps: impacts

Asian Paper Wasp impacts are not well understood in New Zealand. However, numbers appear to be increasing across New Zealand. Paper wasps feed on larvae and caterpillars of moths and butterflies. Paper wasps could be a cause in declining moth and butterfly numbers, which is a real concern. So controlling paper wasps (along with german or common wasps) should be considered as important as controlling any predator species.

All introduced wasp species are likely to be having a massive impact on our native biodiversity. It's just that it's difficult to quantify the loss of invertebrate species such as moths or butterflies. Plus the impact of the loss of these species on other flora and fauna in the New Zealand ecosystem landscape.

We only know that moths are critical for the reproduction of many of out native plant species. Plus form a part of the food web for other species, such as birds.

Unfortunately there is no targeted control of paper wasps available.

Locating their small nests and destroying them is the best option. More easily said than done. Nests vary in size (up to fist sized) and are often well hidden away.

Other than destroying these wasps where possible, there are options around deterring the Asian paper wasps from wooden surfaces.

paper wasp 2

Wiping out invasive wasps a 'critical issue' for New Zealand's environment

A pest control method inspired by Greek mythology is one of the latest weapons being developed in New Zealand's war on invasive wasps.
Professor Phil Lester of Victoria University spoke at Nelson Marlborough Institute of Technology on Tuesday night about a research project he is leading aimed at wiping out wasp populations.
Lester, an expert in insect ecology, said it was appropriate that he was giving the talk in Nelson, which he said was the "wasp capital of New Zealand".

Source: http://www.stuff.co.nz/environment/85957974/wiping-out-invasive-wasps-a-critical-issue-for-new-zealands-environment

10 Facts about wasps

Here are 10 seriously worrying facts about wasps to consider.

  1. The German wasp (Vespula germanica) was first found near Hamilton in 1945; the common wasp (Vespula vulgaris) has been in New Zealand since 1978
  2. The beech forests at the top of the South Island have the highest densities of wasps in the world; but wasps also occur in many other habitats across New Zealand
  3. On average, there are 12 nests per hectare in beech forests, that’s about 10, 000 wasps per hectare!
  4. The highest number of nests recorded was 50 - 60 nests per hectare, the equivalent of 25 - 30 nests on a football field
  5. The largest nest ever found was four metres high and contained about four million cells
  6. There is a greater biomass of wasps (3.8kg/ha) in beech forest than all the native birds plus stoats and rodents put together
  7. The public voted wasps as “most disliked wildlife” (along with rats), because they spoil enjoyment of outdoor recreational activities
  8. Wasps destroy or seriously damage 8-9% of honeybee hives in New Zealand each year
  9. Wasps affect native foodwebs, and negatively affect the behaviour of native birds
  10. The predation rate of wasps on some native invertebrates is so high that the probability of their populations surviving through the wasp season is virtually nil


Landcare Research

Study evaluates costs of wasps to NZ

This report estimates that introduced wasps cost New Zealand’s economy more than $130 million dollars a year, with the biggest economic impacts on farming, beekeeping, horticulture and forestry workers. 
This assessment was based on a literature review. Information was collected from previous studies and from affected sectors in New Zealand to estimate the total costs of wasps, ie the costs that could be avoided and the opportunities that could be gained if wasps were not present in New Zealand.
New Zealand has some of the highest densities of German and common wasps in the world. Wasps have huge social and biological impacts; they are one of the most damaging invertebrate pests in New Zealand, harming our native birds and insects.
This study found that wasps also have a major financial impact on primary industries and the health sector. This includes:
  • more than $60 million a year in costs to pastoral farming from wasps disrupting bee pollination activities, reducing the amount of clover in pastures and increasing fertiliser costs.
  • almost $9 million a year cost to beekeepers from wasps attacking honey bees, robbing their honey and destroying hives.
  • wasp-related traffic accidents estimated to cost $1.4 million a year.
  • over $1 million each year spent on health costs from wasp stings.
  • on top of the direct costs, almost $60 million a year is lost in unrealised honey production from beech forest honeydew which is currently being monopolised by wasps. Honeydew is also a valuable energy source for kaka, tui and bellbirds.

Bait station set up Ngaruruoro

This shows a typical bait station set up to dispense Vespex® wasp bait. In this situation a wasp infestation is being controlled on private property adjoining the Ngaruruoro River in the Hawkes Bay- the riparian area is the source of many nests, resulting in the high numbers of wasps infesting this property.


IMG_8190 (1)

Wasp feeding on Vespex®

This shows wasp feeding activity on Vespex® wasp bait. Wasps feed on this bait and carry it back to nests. Nests are destroyed with 2-3 days of bait being dispensed via bait stations, enabling wide control of areas where nest sites cannot be located.

wasp vespex

Wasp nest in attic

This wasp nest was destroyed in an attic recently. The nest was about the size of a football and attached to the rear of a filing cabinet and box. The wasps had eaten their way into the box and made it part of their nest.


Controlling single nests

I've been asked if we are able to control single wasp nests, often on private property in urban areas or life style blocks.

The answer is yes! We do undertake this work. If the nest entrance can be found, it's more than likely the nest can be destroyed using insecticidal dust, applied directly into the nest. Sometimes this requires more than one application.

We offer a fixed price for single wasp nest destruction- call or email for more information. No charge until the job is complete and wasp nest totally eradicated.

Here's one nest destroyed just recently in central Hawkes Bay. This nest was located pretty much on the property owners back door step next to their verandah…not a comfortable situation at all!

wasp nest

Mites to control wasps?

Landcare research is undertaking a study into the biological control of wasps with mites.

The cost to NZ primary industry of wasps is $130 million per annum according to Landcare Research