“Just kill the bastards.”

Posted by Theo Van Noort @TVanNoort

I’ve heard this frequently of late, particularly when I tell people I study wasps. It’s a widely held sentiment here in New Zealand, a loathing barely matched by feelings directed towards the infamous possum.

Of course, there is something particularly terrifying about a creature that not only stings repeatedly but can also fly (read: stings to the face, shoulders, knees and toes – no problem). Pair this with a temperament more volatile than a rest-home pumped on prune juice and you can see why wasps might have garnered this reputation.

To clarify, it’s not New Zealand’s assemblage of solitary native wasps causing such affront (read earlier blogs by Tom and Zane), but rather invasive German (Vespula germanica) and common (Vespula vulgaris) wasps. These social wasps build nests and have distinct caste systems dividing the role and function of each individual in the colony.

Vesp kills Apis HB

A German wasp attacks and kills a honey bee (Apis melifera). Beekeepers lose approximately $9 million a year solely from wasps attacking honeybees, robbing honey and destroying hives. Photo credit: Henry Bennett

These two species present an unprecedented problem to New Zealand because they thrive in competition against our “naïve” flora and fauna. Vespula wasps are generalist predators and have great ecological plasticity: they can adapt and change their behaviour to best utilise the resources available in a given environment. Long story short, they decimate invertebrate populations via predation, dominate important carbohydrate resources such as honeydew in beech forest, and probably pose a direct threat to native vertebrates like lizards and birds. Moreover, public health, recreational needs and economically important industries such as horticulture, apiculture and silviculture are also detrimentally affected by Vespula wasps. In dollar-speak: ~$130 million dollars in damage per year. 

Vesp cent

Vespula wasps butchering a giant centipede.

Given these traits, it’s easy to understand the enormous need to develop new tools with which to control Vespula wasp populations.

Earlier this week I had the opportunity to attend an open workshop run by the Wasp Tactical Group in Wellington: Tactics and Tools to Reduce the Pain of Pest Wasps in NZ. This workshop brought together scientists and other interest groups from a range of different organisations to collaborate and update the current status and future prospects of Vespula control. Despite the variety of backgrounds within the group, everyone was unified by this desire: to reduce the immense damage caused by Vespula wasps.

Vesp on Odonata

Vespula wasp attacks a giant bush dragonfly (Uropetala carovei). New Zealand’s invertebrate fauna are “naive” to aggressive social insects- their evolutionary history has left them defenceless to Vespula.

Through the day we heard from the different scientists about the range of tools under development by the Bioheritage National Science Challenge  for this very purpose. These control tools include the Trojan female technique, biocontrol using mites, manipulating behaviour using pheromones and semiochemicals, and targeted chemical baits. It also includes a modelling component to understand how these different tools might be used and integrated. Further to this is developing an eradication strategy, perhaps following the tradition of mammalian pest eradications which first targeted small islands.

While acknowledging the hurdles ahead, the floor was optimistic, particularly around the success and public interest to date in Vespex . Vespex, an insecticide developed by Merchento, has proven effective for drastically reducing the abundance of Vespula wasps in areas where it is applied whilst leaving other insects like honeybees unharmed. While Vespex is by no means a silver bullet, if coupled with these other techniques still under-development we may have a good chance at “reducing the pain” of these pest wasps.

Or, in other words, killing the bastards.

Theo image

Theo Van Noort is an MSc student in the Centre for Biodiversity & Biosecurity, School of Biological Sciences, University of Auckland. He is investigating the attractiveness of different lures to Vespula wasps, as well as their potential role in pollination and seed dispersal. He is supervised by Jacqueline Beggs and Imogen Bassett

3 thoughts on ““Just kill the bastards.”

  1. Great post. The visceral hatred in the community of Vespula spp (they ARE NZ’s most deadly spp in terms of human mortality) can be harnessed in getting support for research funding. Keep working on getting cross-sector support (viticulture, dairying, apiculture, human health etc) because conservation impacts alone will never be a sufficient incentive for government funding into research for the many tools needed for wasp control. It will need to be a multi-faceted approach. I reckon that the $130M pa cost is extremely conservative and likely to be less than half the real cost. Cheers

    Liked by 1 person

  2. Pingback: Invaderende veps – Insektøkologene

  3. Pingback: The birds and the bees (and the wasps?) | Ecology Ngātahi

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