FMC continues its research into the best ways for pest managers to use Biflex Mikron insecticide, this time testing its repellent qualities against ants.
There is the perception that pyrethroids are repellent to ants and therefore treatments create a ‘barrier’, repelling ants from an area or preventing them entering a building, rather than creating a treated zone that the ants walk on, resulting in their death. But is this really the case, particularly when considering dual-active formulations?
Biflex Mikron is a dual-active combination of pyrethroid (bifenthrin) and neonicotinoid (acetamiprid). FMC has been working to answer pest managers’ questions regarding its mode of action. Previous issues of this magazine shared the results of an Australian trial that answered the question: “Are Biflex Mikron treated surfaces repellent to German cockroaches?” The trial results showed quite conclusively that German cockroaches are not repelled by surfaces treated with Biflex Mikron. But what is the effect of Biflex Mikron on nuisance ants? Are Biflex Mikron treated surfaces repellent to ants?
To answer this, FMC again engaged experienced pest researcher Scott Kleinschmidt from Australian Timber & Pest Research (ATP Research) to conduct a scientific trial. In the trial, two types of surface – ceramic tile (non-porous) and plywood tile (porous) – were either treated with Biflex Mikron at the label rate for the relevant surface, or treated with water only, and left to dry for 24 hours. There were four replicates for each treatment on each surface type (making 16 test tiles in total).
After the 24-hour drying period, a portion of cooked chicken breast was positioned in the centre of each tile and the test tiles placed out in the field at locations of high black ant activity. The ants could then choose whether or not to travel over the treated surfaces to reach the food. A count of the number of ants present on each surface was conducted every ten minutes up to the 30-minute mark, and then again at 60 minutes.
The hypothesis was that if the Biflex Mikron treatment was repellent to foraging ants, there should be fewer ants present on the Mikron-treated surfaces compared to the water-treated surfaces.
At the end of the 60-minute trial, around 20% fewer ants were present on the Mikron-treated non-porous plates – although still over 350 ants per plate! But there were actually 5% more ants on the Mikron-treated porous plates, compared to the water control. Although there is always variability between replicates in field trials, the results quite clearly show that ants will happily walk over Mikron-treated surfaces to forage – they are not repelled. Figure 1 shows ants happily foraging on Mikron treated tiles and as they say, a picture speaks a thousand words.
Although the trial wasn’t designed to look at mortality, when the tiles were collected 24 hours after placement, a number of dead ants were lying on and near the Biflex Mikron treated tiles (Figure 2).
This trial was undertaken as part of FMC’s commitment to increasing its knowledge base regarding what FMC products can and cannot do, for the benefit of pest managers. It is an add-on to the already large quantity of trial data submitted to the APVMA that proves the efficacy of Biflex Mikron.
