Danger: wasps about

Apr 27th, 2016 | By | Category: Latest News, Our Patch
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Wasps, the flying, yellow and black bullets of evil are everywhere.

Conditions have clearly been favouring wasps and swarms of Asian paper wasps are everywhere while the telltale signs of the in-ground nests of German wasps can be spotted if you are alert to them.

So it’s a good idea to know what wasp is what and what to do with them and their plans for world domination.

What wasp is what

There are four species considered pests in the Waikato – the German wasp, the common wasp, the Asian paper wasp, and the Australian paper wasp. All are accidental introductions, explains the very informed Number 8 Network.

Asian paper wasp (Polistes chinensis)

Asian paper wasp

An Asian paper wasp. Only the females sting. (Photo: David Riddell)

These guys are smaller and thinner looking than the German and common wasps, from 13 to 25mm long. They are yellow and black and have long legs which dangle beneath their bodies during flight. For most of the year only females are seen but in the autumn (i.e. now) males appear. These are smaller and don’t sting. Much of the swarming activity that is so obvious at the moment is courtship behaviour and a very high proportion of the wasps appear to be males – so those swarms may not be as big a health hazard as they seem.

If you have a bunch of paper wasps at your place, have a closer look and see if you can tell how many females you’ve got, since they are really the only ones to worry about. They stand out among the males as being bigger and blacker. They have faces which are striped yellow and black, while males’ faces are almost entirely yellow; males also have antennae that are curled at the end, and more extensive yellow colouring overall. If you’re struggling to see the differences, try spraying a few and checking them out more closely once they’re dead. But be careful, because it’s possible to get a sting even from a dead female.

After mating the males die, while the females retire to sheltered spots such as woodpiles to over-winter.

They gather fibre from wood and plants, which they mix with saliva to form small paper nests, usually up to about 10cm in diameter. These mostly hang from vegetation or under eaves but can also be in more confined spaces such as under roofing tiles. Asian paper wasps are considered to be less aggressive than German wasps. They were first recorded near Auckland in 1979 and by the early 2000s were established around here.

German wasp (Vespula germanica)

German wasp

A German wasp – aggressive and will string humans, animals and insects (Photo: David Riddell)

These are plumper than Asian wasps, with smooth bodies, 12 to 17mm long (although queens are larger.) They have more yellow colouring than Asian paper wasps and have black dots on either side of the back. They are aggressive, and will sting humans, animals and insects. Their nests are also made from paper, but are much larger, and usually underground. Queens appear in the autumn, obvious from their large size, and over-winter much like paper wasps. Hibernating queens tuck their wings under their legs, so that at first sight they may appear wingless. They have been in the country since the 1940s.

Common wasp (Vespula vulgaris)

Similar to the German, but have more extensive areas of black – they don’t have distinct black dots on the back. Their sting is also nasty. Common wasps became established in New Zealand in the 1970s and they are now the main wasp in beech forests. Round here they’re less common than German wasps and have only been in the north Waikato since the 1980s.

Australian paper wasp (Polistes humilis)

These sensitive souls don’t like frosts and live in warmer, coastal areas so we don’t see them around these parts. They’re slightly smaller than Asian paper wasps and orange-brown in colour.

Dealing to paper wasp nests

Although it is tempting to have a crack at them when you discover the nest, wait until evening or first thing in the morning when the wasps are, literally, chilled.

Note where the nest is and go back later with the flyspray. Once the wasps are gone remove the nest and burn it if possible, as other wasps will plunder it for material for their own building projects.

Dispatching German wasp nests

These are a little trickier to deal with but they can be destroyed. Once you notice the wasps try to follow their flight path to discover their nest. You can (carefully) flick white flour on the critters to make it easier to track them.

Visit the local hardware shop for a suitable insecticide. Success has been reported with Carbaryl powder. The poison can be carefully puffed through a tube down into the nest, taking great care not to inhale.

Others have put the powder into a jar lid nailed on to a long stick that is used to put it into the nest.

Keith Holborow

Expert wasp killer Keith Holborow (Photo: Annette Taylor)

Advice from expert wasp killer Keith Holborow: “I just walk quietly around, and look and listen for them. They nest in the ground, and you can see them coming and going. Often there will be little white chips outside it, which is another give away. If the hole has spider webs or leaves in it, look elsewhere because it’s not active.”

What to do (or not to do) around wasps

Stay calm. Holborow advises staying out of their flight path if you possibly can.

“Everybody has their pet theory about what to do if wasps get angry, some people recommend running like crazy, but you should run with dignity, not slapping yourself. Every person I’ve ever seen stung by a wasp has swatted at them. While it’s an understandable reaction, it’s the worst thing to do. Move away steadily.”

Another option is to freeze. “This seems to work well too, as long as you have the self-control to watch a wasp hovering past your eyes, checking you out. You hope they won’t do anything more about it, and almost for sure they won’t.”

He had received differing advice from the experts – “The Auckland Park rangers say run, run like hell, but the Auckland Park wasp exterminator says freeze and stay out of the flight line. When they lose interest, walk away quietly. And that always seems to work for me.”

And if you are in the bush, he says carry antihistamine and a first aid kit with you.

Damn, I’m stung. Now what?

Usually wasp stings cause only local reactions but sometimes severe allergic reaction occurs – ring 111 if needed.

  • If stung on the neck, face or in the mouth, take an antihistamine and see a doctor immediately. Stings can cause swelling in the throat, making it difficult to breathe.
  • Otherwise, apply an ice pack on the area, or apply antihistamine cream (and take it easy for the rest of the day.)

The natives

New Zealand also has 29 native wasp species – they rarely sting and are solitary hunters – more intent on finding food for their offspring.

Scientists are developing a range of tools for controlling wasps. It is likely that several methods will be needed to solve our wasp problem.

For more information about wasps and how to deal with them click here for a guide by the Waikato Regional Council.

Thanks to Number 8 Network for allowing us to share this timely and informative post.

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3 Comments to “Danger: wasps about”

  1. Ava B. says:

    Very nice article on wasps and how to deal with them. In case you are interested, we’ve put together an extensive guide on Australian wasps including descriptions and a lot of tips on handling them properly. The entire material is at https://fantasticpestscontrol.com.au/blog/fantastic-guide-to-wasp-nests/

  2. Anna Simmonds says:

    Hi there, I’m trying to find out more information on the 29 native wasp species in New Zealand – wondering if you could help me by directing me to a person or literature I could read on them? Many thanks,
    Anna Simmonds

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