Wasp bait key to wasp control
The developer of a bee-friendly, wasp-killing weapon is expecting a fierce battle to control pest numbers this summer.
Nelson insect ecologist Richard Toft said the need to keep on top of wasp control had been brought home by an increased year-round presence of German wasps between Waikato and Northland.
‘‘A lot of people are reporting wasp activity in spring, particularly some of the beekeepers who were having their hives hammered by wasps quite early in spring. Typically that means there’s been a high number of over-wintering German wasps creating those high numbers at unusual times of the year.’’
Since his Nelson-based company Merchento released Vespex bait in 2015, Toft has helped reduce the wasp population around the top of the South Island by up to 98 per cent in baited areas.
However, Toft said warmer conditions throughout spring and into December indicated the war to eradicate the black and yellow pests was set to reach new heights.
‘‘Our predictions are it’ll be a fairly high wasp year going by the fact it’s been a warm and drier spring which tends to favour wasp development – last year was relatively low so that’s normally followed by a high year, all else being equal.’’
Toft had mixed feedback that some people had seen barely any wasps and others had reported wasps on possum carcasses, ‘‘so we’re already gearing up for wasp control as soon as early January’’.
Vespex is a frozen, proteinbased bait targeted at wasps that contains the insecticide, fiprinol.
The bait stations are used in late January, early February when wasps have switched to eating protein and as part of the management of pesticide.
Being protein-based it is not attractive to bees and a single application is enough to kill a wasp nest completely. Any leftover bait is removed from the bait station a week later.
Key users have included the for- estry industry, private conservation groups and beekeepers who lose a lot of hives through wasp predation.
In order to purchase Vespex you need to be registered with Merchento as an approved user. You do not need to be an approved user to help out with a wasp baiting project, but the project must be directly supervised by someone who is an approved user.
Toft said while Merchento had an ongoing plan of development for the product, the seasonal demand for Vespex meant he had a tricky balancing act between research and action to refine Vespex’s efficacy.
‘‘Unfortunately we’re a bit limited in the fact that we can only do very experimental testing when there are wasps around – it’s a bit of a catch-22 in that the time where we’re most busy in the office is the time when we need to be doing most of the work out in the field as well.’’
Efforts to get Vespex onto the shelves of hardware and retail stores has also proved challenging. The fact the bait has to be frozen is one challenge.
‘‘The main issue is around packaging, but also the fact that it’s in the freezer in its frozen form and that’s just not very attractive to retailers.’’