Wasps and our journey on how we manage them differently at Gippsland Pest Management

The trial program for “Vespex European Wasp Lure in combination with Ensnare Pro”

In 2019, the European wasp population in the Gippsland region was one of the worst seasons the area had experienced. This was mostly due to winter seasons that were drier than usual and a very hot summer for 2018/2019. In most cases if a European wasp nest can be found it’s a simple process for a professional pest controller to remove/treat. However, European wasps have been known to travel up to a kilometre from there nesting location making it difficult in some cases to conduct a direct application treatment to the nest as the nest can be difficult to locate.

These wasps can be real issue for businesses and cause safety concerns to humans and animals. At the time no products were registered for the treatment of European wasps’ nests from a distance. There had been a lot of home remedies like mixing the active fipronil with cat food however this was a very unproven method, and completely off label and illegal, and could run the risk of hurting none target animals.

A major reason for the lack of treatment options was due to the wider risks of hurting the local population of honeybees. The team at Gippsland Pest Management were receiving countless phone calls from schools and businesses asking for help with European Wasps around their premises but with no nest nearby this was the catalyst for our Team and founder Shannon Grohs to try and find a better treatment option.

Shannon’s first step was to reach out to David Priddy the founder of Sundew Solutions an Australian based chemical manufacturer. Shannon and David had previously worked together on other collaboration projects like the Duckbill Duster. Shannon articulated his issues with the wasps in our region and asked David if he was aware of any products in the pipeline, David responded that there were products in the works, but they were not yet registered or tested for the Australian market, however testing was underway in New Zealand. David advised that to get the product registered for the Australian market it would need to undergo vigorous trials that tested:

• The safety of the product and the impact on other non-target pests.
• That the product was capable of the desired outcome – To prove this outcome 10 or more wasp nests would need to be baited and observed daily to document the outcome of the nests and if they have collapsed solely due to the baiting process. A control nest would also be required in the same environment but that didn’t have access to the bait.

Shannon was integral in identifying the test site location at a farming property in brandy creek, this site had over 12 nests in a rear paddock that ran along the creek line. And so, the trials began.

Initially the trials began with a solid bait and a liquid lure, the trials team had great optimism that this bait combination would be successful as it had shown great promise in New Zealand. Each day Shannon would complete a daily inspection of the wasp baiting stations, the daily inspections involved counting the number of wasps leaving each known wasp nest onsite, the number of wasps interacting with the wasp baiting stations and if any non-target species, such as bees were interacting with the wasp baiting station. The theory of the product had indicated that the deterrent in the bait would only last a few days in the field at its optimal performance level.

At the first inspection Shannon was bitterly disappointed as the wasps onsite hadn’t interacted with the solid bait at all and showed very little change. After this disappointing start Shannon decided to test just the liquid lure in the wasp baiting stations and to remove the solid bait completely. The result of this decision was experienced almost immediately, wasps started swarming the liquid. This had proved that the wasps had been deterred by the solid test bait in the mix. Whilst this was great information, there was still one problem the liquid lure didn’t contain any poison, so we were effectively feeding the wasps.

This result had Shannon thinking and after consultation with David and the team at Sundew Solutions the decision was made to trial another product already registered in Australia in conjunction with the liquid lure that contained the same active as the proposed solid bait. David was sceptical that this product would be successful as its chemical composition meant it was likely to fall out of suspension with the liquid lure. But agreed with Shannon that it was worth a go. So, the wasp stations were reset with this new mix of liquid lure and liquid poison.

At the next inspection, not even 24 hours later the results were astounding, all the bait had been consumed, this had occurred so quickly there was no chance of the product falling out of suspension with the lure and no other non-target pests had an opportunity to encounter the bait as the deterrent was still active during the time frame it took to be consumed. It seemed we were on a winner, the only thing left to do was to collect the data and observe the outcomes.

Over the next two weeks the trials team observed a massive drop in the wasp population at the test site, with each test nest site showing a colony collapse. Some of these nests were over 1klm from the wasp baiting station location. Over the two-week test period, litres of bait was consumed by the wasps. Once all the nests had collapsed, and the population in the area had dropped to zero the hard work was still to come compiling the data together.

This was the first time this had been done in Australia with some surprising results, it was discovered that the average amount of product required to kill a nest was almost 300ml’s of liquid, this finding disproved that the old home remedy of cat food and fipronil mixed would contain enough product to reach colony elimination.

Another interesting discovery was when a nest reached colony collapse many of the wasps turned into zombie like shells of themselves, they would stay around the nest but not have any purpose, such as foraging for food. This result is good because they stopped foraging in the surrounding areas, but bad because there was still the opportunity, they could sting a passer-by that interacted with the nest. This finding confirmed that if a nest could be found then the safest treatment would be direct application to the nest. As the average time to colony collapse was taking upwards of three weeks.

After all the trial data was collected and sent off, it was a matter of waiting for approval. Approval was received the following year in 2020 and the first ever European Wasp Bait “Vespex European Wasp Lure in combination with Ensnare Pro” was approved for use in Australia by Sundew Solutions. As the deterrent for non-target species only had a short lifespan Sundew Solutions designed an accredited training program to ensure all professionals utilising this product understood this limitation and the ways to reduce this risk to our environment. Today wasp baiting has become common practice among pest controllers in South Australia, New South Wales, and Victoria. The original trial site was so successful that 3 years later only one nest has reappeared in the following seasons. Previously this site had experienced 5-10 nests each year.

Today Shannon and Gippsland Pest Management continue to provide assistance in trials and data regarding European Wasps with lots still to learn, we are keen to see where this journey will take us in the coming years.