Sunday, March 28, 2010

Angry Wasp Season

The 2009/10 wasp season has not been as bad as in many past years, in most parts of the country. This may be due to many areas having it too wet and other areas being too dry. However, there are still wasps aplenty about and it this time of the year that they can be most aggressive.

It is thought that they get ‘angry’ in autumn because they change their feeding habits towards larger amounts of protein and perhaps the workers know that winter and their death is coming. Nest and colony sizes are at their numerical high points about now and so dealing with a nest can be hazardous if not handled correctly.

When dealing with wasp nests I advise –
  • Do Not spray nests with liquids. Liquids tend to make wasps even more aggressive. Use powder type insecticides such as NO Wasps Insecticidal Dust or Carbaryl 80.
  • Do Not use large amounts of powder. A number of light applications of powder is better than one large dose.
  • Apply powder at dusk or at night on a dry day. Wasps will be less active.
  • Avoid dealing with wasp nests on muggy dull days. Such conditions seem to make wasps aggressive.
  • Puff or place powder IN the nest entrance. Worker wasps will walk the powder into the colony where it will kill larvae and queens.
  • If the actual entrance cannot be accessed, several applications of powder to areas where wasps land and enter nest will be effective.
  • If the nest is in amongst vegetation it can be difficult to identify the nest entrance. In this situation watch carefully to see where wasps enter the nest. Apply powder to the areas where the wasps land before walking into the nest.
  • Once the nest is destroyed and no more activity is seen any excess carbaryl powder can be washed away or collected and disposed of safely.
  • It is not necessary to physically remove a nest. Nests are not reused.
Call Kiwicare at 03 389 0778 if need any further advice.


  1. i hate wasps, I have never seen a nest before… but I'm pretty sure I would take off running, for Canada!!!!:

  2. Hi there. Great website, and helpful advice. Have just used NO Wasps powder/Kiwicare on the nest with a friends help. Its above the kitchen, and they chewed through the ceiling…. strange right? Must be Asian paper wasp? So my friend climbed up on the garage and puffed on good blast in the entrance… how long does it take to kill them all off? He did this 8 hours ago, but they are still slight noise. Maybe takes a few days to poison them all? Might have to apply another puff of No Wasps INsecticide dust? Bit freaked out by them, since i saw them tunnel through the ceiling that morning :P. Blocked the hole with see through cellotape was not so smart, as they could see the light, but ended up eating a wider hole above the tape. Ended up taping brown cardboard over that light cellotape area, so they dont seem to be trying to tunnel through the ceiling, but the tape is not holding all day, since oily ceiling in the kitchen. Will need to keep an eye on it sadly, as dont like the idea of wasps falling or flying into the kitchen. Any further advice much appreciated sir. Thanks.

  3. Hello Aaron, In difficult to treat places like you describe it often takes re-treatment to deal with a wasp colony. If they have not stopped activity now you should apply some more powder or if you can access the ceiling space you may consider setting of NO Bugs Bug Bomb in the void.

  4. Thanks for such a quick reply David. Yeah… well, a few wasps come and go every few seconds during the day, and though their is less noise as before…. there is a strange repeating humming noise… it starts up, and stops, starts up and stops… I dont know, but my random guess is that the queen is doing something dodgy… The cardboard I have put in place over the hole in the ceiling with cellotape is hanging by the cellotape, so its not right up against the hole anymore… im too chicken to get up and place it harder up on the hole again, since i would be exposing the tennis ball size hole to the kitchen… This powder, NO Wasps from Kiwicare… it was squirted by my pastor into the hole pretty good from the roof eave where the worker wasps come and go… but… whats the longest it can take before its taken to the queen and she carks it? or do i really need to get the courage up and get up there again tonight to puff some more powder in?… what time would be best to do that? dusk? Tx again David :).

  5. Hi Aaron,

    I was away for a few days, so sorry it has taken a bit longer to reply this time.

    With any luck the problem has ceased, but if not then you will have to re-apply the powder. Dusk (or early dawn) is a good time (assuming it is not raining or not likely to rain) as the wasps will be inactive.


  6. We have had a hornets' nest near our front door all summer. We have coexisted, with no mishaps. A few days ago, however, a friend was stung 3 times at our front door! Don't know why they reacted to her, but they are seeming to be swarming more and are a bit intimidating. We would like to not kill them, but what could be making them mad?

    1. Hello Jacqueline,

      Wasps and hornets tend to become more aggressive towards the end of the season. It is thought that this may be because of a change in food preference towards more protein and more difficulty feeding the colony as it reaches peak numbers.

    2. Thanks for your feedback, How long should this last? How soon might they leave/die off?

    3. Hi Jacqueline,

      Numbers will rapidly drop as cold rather hits. It will depend where in the world you are and how quickly it cools down.



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