He arrived in Tasman as common wasps were swarming South Island beech forests, and he set to work in his lab.
The discovery of the fiprinol-based protein bait provided a valuable new tool for controlling common and German wasps, designed to be used at a key point in their breeding cycle.
Vespex was around 25 years in the making, and Toft’s work was honoured overseas with a World Wide Fund for Nature (WWF) Conservation Innovation Award in 2015.
The accolade recognised the significant breakthrough in conservation, helping protect native forests, insects and birdlife from invasive wasps.
The bait has been used extensively by the Department of Conservation to control wasps.
Now building on that success, Biosecurity New Zealand was analysing data to pinpoint the best time to feed it to the hornets.
At this stage of the breeding cycle, wasps and hornets have shifted their diet to more protein-based food sources.
Biosecurity NZ’s Scott Sinclair explained it could be a critical time window.
“The Vespex bait works by either wasps or hornets rolling it into small balls at the bait station and then taking it back to the nest,” he said.
“It’s distributed around the nest to feed the growing colony.
“During that process, that fiprinol-based bait gets ingested by a whole lot of either other hornets or wasps in the nest, and a large proportion of that nest [die] off.”
While it had become an extremely valued tool for the control of common and German wasps, Biosecurity NZ was not sure how well it would work for controlling hornets.
Some work in France had suggested they would find it attractive.
“The protein-based baits are going to be more effective against the hornets later in the season,” Sinclair said.
“We’re trying to still determine exactly when we’re going to deploy based on our dissections on the hornet nests that we’re finding, because that allows us to understand how our population is developing. The likely window is in the coming weeks.”
To date, there have been 51 confirmed queen hornets found and 61 nests on Auckland’s North Shore.
Vespex was now manufactured and sold by Nelson company Merchento, of which Toft was the director.
What is Vespex?
Vespex is a protein-based bait formulation that contains 0.1% fipronil (a neonicotinoid insecticide) deployed in specialised bait stations.
It is designed to be highly attractive to wasps, which take it back to the nest, resulting in the destruction of the nest.
It is specifically designed not to affect bees or native insects and birds.
Where was it developed?
Vespex was developed by the Nelson-based company Merchento.
Toft, a member of Biosecurity NZ’s Technical Advisory Group and a well-known entomologist in New Zealand, developed the product.
It had been used extensively in New Zealand, including by the Department of Conservation, in both small and large-scale wasp control programmes.
Why is it being used at this part of the breeding cycle?
The timing of the deployment of Vespex in the yellow-legged hornet response is due to:
- the point in the life cycle, as earlier in season, yellow-legged hornets favour more carbohydrate/sugar-based food sources, shifting to more protein-based food sources later in the life cycle
- b) the need for live hornets in the environment to facilitate thebest shot at eradication. Healthy, live hornets are needed to track back to nests so that the whole nest (including the queen) can be destroyed in one go. Vespex too early in the season may weaken these nests, making them more difficult to detect.
What’s the latest with the hornet?
Ground operations are working to find and destroy nests.
To date, there have been 51 confirmed queen hornets found and 61 nests on Auckland’s North Shore.
- RNZ
