Tangihua Lions Lodge Wasp Control Project

Tangihua lions lodge instigated the first trial of Vespex in Northland.

Issue

We have had significant problem with students being stung by wasps. Some schools in the past had to pull out or would not use the tramping tracks because of this

Conclusion

The trial was very successful and we will extend the programme and implement it annually.

We have never been able to control the wasps now we can

Results

Nests

15 nests were monitored

• 11 were inactive after the trial
• 1 had significantly reduced wasp numbers entering and leaving
• 3 Were relativity the same 1 one these nests was 50m off the bait line, 2 were very close to 1 or two other bigger nests which had become inactive. Comment The proximity of other nests seems to have an effect and perhaps the wasps are territorial and only after a nest is destroyed will another nest move onto the bait.

Wasp counts

Pre-bait trial were done around the lodge

• 12 wasps were counted on the baits.
• Post baiting in the same area 1 wasp was counted on the baits

Post bait trials were carried out. In the control area 7 wasps were counted on the baits. The area was split into 2, a sunny grassy area and a bush area. They were on the same line Sunny grassy 3 bush 4

At the same time a similar bait line was set at the lodge. Results for wasp numbers:Sunny grassy 1 bush 0 . The bush part of this was a track which is a notoriously bad spot for kids being stung

Visual

When we were setting out the stations and baits there appeared to be three distinct areas which could merge

1. Sunny grassy – The highest numbers of wasps were seen here, the range was from 5 – 10 in a 3m circle
2. The tracks on the lower more sheltered bush area if you stopped and counted usually 2 – 4 wasps could be seen mooching on the track ahead over 2 m
3. On the higher ridges not a lot of wasps could be seen but the 1 nest was found

Post baiting

1. Sunny grassy ranging from 0 to 5-10 depending on the site
2. The tracks on the lower more sheltered bush area usually 2 wasps per 100m, it was unusual in most places to see wasps
3. On the higher ridges Very few wasps and the nest was inactive

Sound

When setting out the bait stations and baits there was a very loud constant buzzing noise. Post baiting this was significantly reduced and sounded more like it was coming from outside the baiting zone.

Stings

pre baiting

Stings were a common occurrence

• one school counting 27 in a week
• two DOC workers were severely stung after coming close to a nest by a track
• Another school recorded, one student receiving 17 stings and many others were stung as well
• While I was chatting to a teacher three kids were stung going past a notoriously bad spot

Post baiting

A substantial reduction on stings (3 on day two of the bait laid) recorded and no others. The teaching staff at the camp who have come year after year are very impressed with the difference.

Comment

Not all wasp nests were destroyed and so you could move from an area of very little activity to one of much more depending on the proximity of the nests.

Prior to setting out the baits there was heavy activity everywhere but in all areas including those close to the surviving nests there was a substantial reduction.

Methodology

We have used a product called Vespex.

We have been approved by the Department of Conservation, ministry of health and regional council to use it in the Tangihua ranges which means it meets all the specifications mentioned in background

This is the first time it has been used in Northland.

Pre baiting

In order to trigger setting the baits we required 20 wasps to be counted in the bait trial. The bait line was 20 dishes 5m apart of cat food left out and counted after 1 hour. I counted 15 and decided not to proceed.

I contacted DOC and was informed two of their staff had been badly stung on one track. The school that hired the lodge counted 27 stings in four days. The following week another school one lad received 17 with many other being stung.

I was away for three weeks and decided to commence with the baiting immediately on return irrespective of the number count

Bait stations

They were set out 50m apart just off all the most popular tramping tracks. We were able to do about 1km and hour actual setting out. There was additional time due to many tracks going to a point and then having to double back.

The total time was 13 hours for 220 bait stations. The tracks were good walking tracks ranging from easy to steep. There was an estimated 10.5km of track with stations on them

I under estimated the number of stations plus because the tracks were wound around the hills the stations were often less then 50m apart in a straight line

Bait set out

We were able to lay 220 baits using two people in 14 hours total. We laid the baits at about the recommended tramping times on DOC signs. We followed the instructions carefully with one exception. We carried the bait in a 20l paint container clearly marked. The container was lined with a rubbish bag

The reason was

• Taking off a back pack and getting at the bait through various bags every 50m was slow
• Repacking the bait etc was very slow
• No matter how hard you tried when putting the bait into the box there was some spillage at some point. Doing it in or over a 20l container contained any spillage

The baits were removed on day 6 which was occasional rain and over cast. Because of this the post bait trial was completed the following day at 12 pm on a fine sunny day.

The removal of baits was one person covering the ground at walking pace

Bait trials

Post baiting

The bait line was 20 dishes 5m apart of Sardines left out and counted after 1 hour. note sardines were used as a comment was made that some catfoods could have insect deterrents in them hence the low pre bait figure

In the control area 7 wasps were counted on the baits. The area was split into 2 – a sunny grassy area and a bush area. Sunny grassy 3 bush 4

At the same time a similar bait line was done a the lodge. Sunny grassy 1 bush 0 . The bush part of this was a track which was a notoriously bad spot for kids being stung.

Follow up

We will re-bait the area where the wasp nests we monitored were not destroyed

Background

The Tangihua lions lodge is an outdoor Education Centre for Schools and other organisations.

The Lions Lodge is uniquely located in the heart of the Tangihua Ranges, a native conservation forest over seen by the Conservation Department.

By providing affordable accommodation and outdoor education facilities it has become the number one destination for school camps in Northland with over 10,000 guests since its inception.

We have had significant problem with students being stung by wasps. Some school in the past had to pull out or would not use the tramping tracks because of this

We have never been able to control the wasps now we can

Wasps are a significant problem for lodge users as they are for all New Zealanders

Introduced wasps have serous negative impacts on both urban environments and natural ecosystems.

The most common wasp is the black and yellow Vespula germanica wasp. These wasps are often called German wasps, although other names are commonly used by those who have been stung.

Issues wasps create

• Health and safety , stings are unpleasant, a distraction and multiple stings can be fatal
• They are destructive to bees and compete for resources
• They destroy native species and compete for resources

Finding and destroying nests using existing methods have not been successful

The issues are

1. Finding the nest usually means someone has been stung
2. Time and difficulty locating nests, tracking wasps is very time consuming
3. number of nests in the vicinity: There are often several nests causing an issue and missing one means there are still significant numbers of wasps around
4. Approaching a wasp nest to deposit the chemical needs to be done at night or very carefully
5. The chemicals we were using often required repeat visits

We required a method to kill wasps efficiently, cost effectively and safely.

The methodology has to take into account

1. Does not kill bees,
2. Avoid non target invertebrates
3. Not allow the bait be washed into streams or leave a harmful residual
4. Avoid no target species such as birds and other insects
5. Avoid poisoning pets and people –
6. DOC approval – be safe to use in a native forest environment
7. Ministry of health approval
8. Time taken – it would be carried out by volunteers with limited free time
9. Cost as all cost would be passed onto the camp users

We have studied many wasp killing trials and including doing trial work of our own. We are still undergoing practical trials and so suggestions may change

Wasp life cycle

The table(source landcare research) demonstrate the life cycle and best time to attack the wasps. It is when the wasps are actively searching for protein to build up the pupae numbers, late January early February.

Because of the very large number of queens released from each nest and they can travel 4km the control measures will need to be annually

More information about vespex

The lodge is run by the Tangihua Lions Trust, a non profit organization, whose aim is to minimise students school camp costs so all students can use the facilities. We reinvest any surplus back into the lodge.

If you hire the lodge you are helping us achieve this goal. We would like to thank you and all our supporters for doing so