How I Learned to Stop Worrying and Control Wasps with Vespex

Department of Conservation —  07/03/2022

By Brian McDonald

Common wasp
📷: Sid Mosdell

When I started at DOC last October, one of the communications portfolios I inherited was our partnership with Stuff’s Wasp Wipeout programme. As a long-time fan of pest control, and a lifelong hater of wasps, I was pretty stoked.

But, of course, I had to get up to speed. I learned about what happens during a Wasp Wipeout operation, what we had done in the past, and the tools we use. In particular, I was especially interested in Vespex, the bait used to lure in and eradicate these black and yellow menaces.

How better to understand wasp control than to get certified in the very substance we use to control them?

So obviously I didn’t ACTUALLY get certified; that costs a cool $58, and neither I nor my manager would have approved the expense on the grounds that “I thought it would be funny”. So I just did the test, and was content to settle for bragging rights.

Easier said than done, apparently.

That test is hard, and a passing grade is 31/33. Been a while, but I’m pretty sure that’s even more strict than the driving test, and definitely more than I ever had to get in university. Arguably that highlights flaws in the education system more than anything else, but still. My point is, I did not pass the test. Not even close.

But hey, let’s not get ahead of ourselves. Why do you even need to pass a complicated test with a near perfect score just to kill some spicy sky raisins? Well, let’s start from the beginning.

A close up of a common wasp.
📷: D. Sikes

Let’s Talk About Vespex

Vespex is made with the commonly used and astonishingly effective insecticide fipronil, well known for giving unwanted invertebrates a terminal case of dead. While very low risk to birds, pets, and people, the problem with fipronil is that it’s an equal opportunities eradicator for everything else; it will kill basically any bug that bites it. What sets Vespex apart is that it’s protein based, meaning that wasps find it delicious and it’s not at all attractive to bees.

We like bees. Wasps not so much.

Nelson-based company Merchento developed Vespex in conjunction with us to help control wasp populations. Vespex was designed specifically for the control of Vespula wasp species (yellow jackets) and, when piloted on five public conservation land sites in 2015, reduced wasp activity by more than 95%.

That’s a lot of dead wasps.

Introduced wasps are a significant pest which harm our native birds and insects, and are a threat to human health and recreation.

Vespex can be purchased from Merchento, but only by approved users. Since the bait contains an ecotoxin (our buddy fipronil), there are some strict stewardship controls in place to ensure that the bait is used in a way that does not present a threat to the environment. Fair call, right?

So long story short, to use Vespex you need to become an approved user, and who am I to tell people to do this if I can’t be bothered learning about it myself. Ok, let’s do that.

I watched the video, which explains all the phases in wasp control. I read the product label on the Merchento website, which brought me right back to my uni days with a ton of numbers and toxicity vs efficacy stats that are the exact reason I went into communications instead of science.

Then came the fun part: sitting a short online quiz based on the video and the product label. OK, fun might be a stretch. Honestly this sounded easy, but it absolutely was not. They really do not want people (like me) who just skim the information getting their hands on this bait. And that’s fair; as a pesticide, it’s serious business.

Controlling the Control

Now you may be wondering how exactly Vespex can manage to only target wasps. So was I.

As a protein bait, wasps are interested around mid-summer through to early autumn; this is when they stop chowing down on honeydew and get carnivorous to feed up their demon maggots. Bees are far more chill than this, and never eat meat, so they’re safe.

Other insects also need protein, however, and we don’t want weta getting their mandibles on Vespex; it’s the classic Shakespearean murder farce, when the killer has to make sure their victim drinks the right cup and no one else gets into the cyanide.

Except, you know, with more legs and compound eyes (although that would make King Lear a lot more interesting).

This is why the Wasptek™ bait stations are set up. Elevated away from the ground, our earthbound natives can’t get to the Vespex, protecting them from themselves. Neither can kids or pets, just in case they’re wandering about too. Wasps, on the other hand, flit right on in, grab as much as they like, and carry it back to the nest to feed their larvae. The wasps then share the bait around nest-mates, including the queen, quickly destroying the whole colony.

This also means that you, as a wasp controller, don’t need to hunt through the forest to find and destroy the individual nests.

Less effort, safer work, better results: that’s not just a win-win, but a win-win-win.

Wasps taking bait.
📷: Joe Ruark

Where the Wasp Things Are

Let’s talk about wasps for a second. The easiest way to describe wasps is to imagine bees, but they’re jerks. Wasps were introduced to New Zealand in the 1800s and have been the bane of decent folk and picnickers ever since.

Arguably, wasps are useful in some contexts, controlling other pests and even helping to pollinate flowers and plants. However, bees are much better pollinators, and reducing some pests slightly doesn’t cancel out these flying pain factories menacing decent society. Add to that the damage they do by taking up resources that could be used by other, cuddlier creatures, and you’ll see why we want to give them the boot. Literally and figuratively.

Wasp nest.

Vespex can be used on public or private land, but if you wish to carry out wasp control operations on public conservation land you need to contact your local DOC office to enquire about the permission process you need to follow.

Previously the bait was only licensed for use on public conservation land, but in 2018 it was opened to wider access, meaning that community groups and private landowners with natural areas on their land can now access this targeted bait station method, meaning that more conservation and recreation areas can be protected from the annual wasp onslaught.

The caveat? Pass the test.

After my first (and frankly embarrassing) failure, I went into study mode. I read that label until I could basically recite it from memory, and watched the video twice more. Weird? Yes. Effective?

Well, much like Vespex itself, I was 95% successful, by which I mean I got 32/33 questions right. Could I have gone back and tried for the perfect score? Yes. Did I want to? Hell no.

Waspocalypse Now (well, eventually)

I learned a ton from this experience. Not just about wasps and how to control them (although yes, mostly that), but about innovation in how we run operations, how we protect non-targeted species, and how we make sure people using these methods know what they’re doing.

But even with tools like Vespex, wasps are still a persistent annual problem. While eradication would be amazing, we’ve all got a lot more work to do to make that a reality. And it’s a dang good start, but what’s next?

Well thank you for asking, imaginary reader. There’s a ton you can do to get involved.

Wasps should be wiped out from New Zealand; they don’t belong here, like cheese in coffee (I saw someone do that once and the memory still haunts me). Luckily, DOC’s partnership with Stuff is all about that, and the appropriately named Wasp Wipeout programme is in full swing.

Join a community group in your local area (you can find a list of these groups on the Stuff Wasp Wipeout page). If that’s too much commitment for you, you can always just alert DOC of high wasp density locations while you’re out and about; we can’t get them if we don’t know they’re there.

Get approved for Vespex while you’re at it. You’ll learn a lot about wasp control which, for all my sarcasm, was genuinely fascinating. If nothing else, you can brag about it later, if you like your boasts getting met with black stares and confused chuckles.

You could also study wasp biology and try to invent more ways to control the pests, as it’s vital that the science community keeps working on developing a range of tools to control wasps over the long term. But that might be asking a bit much for most of us. I definitely don’t have the time or mental space to become a… wasp scientist. Entomologist? Vespologist? Wasp-buster?


You can find full information about becoming an approved user on the Merchento website. And, of course, find more about Wasp Wipeout on the DOC website or over at Stuff.

15 responses to How I Learned to Stop Worrying and Control Wasps with Vespex


    This year wasps or hornets?? have taken an interest in my choko vine flowers. They don’t seem to be particularly effective pollinators. In previous years it’s been bees that have busied themselves round the choko flowers & done a good job of pollinating, but this autumn the bees are staying away. I wonder have the wasps somehow scared the bees away? Nearby is a bed of cosmos in full bloom with just a few bees buzzing round.
    I’ve dealt to two wasps nests. One was up under an eave, difficult to reach, so I sprayed it. The other was within easy reach, so I waited until dark, armed with scissors & a jar, snipped the nest stem so the nest fell into the jar, quickly put the lid on, & popped the jar into the freezer. Not a bad way to die & no more toxins ended up around the home & garden.


    Now we just need to get rid of all those paper wasps!


    Loved the article. Thank you for an interesting, informative piece. We live in a new build area on Auckland’s North Shore, When we moved in, in Oct 2021 there were 2 wasp nests snuggly setup on the boundary fence. We were told to wait until dark and spray the nest with normal insect killer. We haven’t done it yet. Following this article I am uncertain if this would be the right thing to do?

      Howard Buxton 02/04/2022 at 8:57 am

      Go to Bunnings or placemakers have large spray for wasps about 34$
      Wait to dark spray nests instant death did 7 nests over 2 nights i covered up but never had a wasps fly at me. All gone. Hours later plucked and stood on nest. 1 was huge
      was easier than powder. good if easy access to Nest


      Hey, I think we got quite similar situation. Moved to new build area in Rodney. Now I couldnt really see the nest but can always see they flying around which I hate so much!


    can you get Verspex in Europe ? Would it work in cold places like the Kremlin ?

    Brent Smith 01/04/2022 at 6:50 pm

    I farm in an area surrounded by doc land and have seen huge numbers of wasps in previous years, hundreds around fruit trees, grapevines , any carcasses and my beehives, however this summer I have seen about five wasps. Also hardly a blowfly, very few green beetles which are usually a curse in the garden. I doubt anyone here is using verspex. Canary in a coalmine?

    Dennis and Chris Topperwien 01/04/2022 at 5:18 pm

    NZ Export Commodities used to come and take away nests to export the pupae delicious snacks overseas. Do not know if they still exist


    We have a big problem with paper wasps. Does Vespex kill those wasps?

    Howard Buxton 01/04/2022 at 3:29 pm

    Loved the article. Well written. On Waiheke major problem. Im just a quarter acre block betwen next door and myself sprayed at night and wiped 7 large nests. Rosemary bush is heaven for them. Be great to have real killer


    In the space of three days a possum leg nailed to a tree was totally consumed by wasps. Just imagine if you died in the bush!


    What a great and entertaining piece! I am happy to be on the lookout and ensure I stamp these guys out (literally).

    Jeremy Painting 08/03/2022 at 9:15 am

    WASPS…. I’ve been exterminating them on a voluntary basis since 2012 in the Waitakere/west Akl area… peak times saw +200 nests a season, with massive reductions in recent years to less than 50, so have leant so much about them, and noticed the influences of very hot summers and droughts on the reduction of nests. I believe that councils have been negligent in their response to wasps, ignoring the massive problem they are, and there should be a subsidised eradication program as expecting the public to pay over $150 to kill a nest that ‘arrives’ on their property is wrong. There should be the same concern as with Kauri Die back.

    Rtr Senior Rtr Senior 07/03/2022 at 2:21 pm

    Great post, I hate wasps with a passion, seeing the decline of Birds presumably due to the Honeydew lost by the invasion of wasps in the beech and the always vicious attacks whenever a successful deer hunt has arisen. I imagine trying to get underwater to evade the mass aerial attack in only 150mm deep creeks must look hilarious. Hopefully a time will come when us not so capable of passing exams will be able to take easy to set baits into the bush.


    Can I just say how much I enjoyed this post? It’s funny (“imagine bees, but they’re jerks”), it’s informative and, well, who doesn’t feel united in a hatred of the little beepers.

    I’ve looked at getting Verspex certified myself a few times but never bothered, but this post might just be the push I needed!