Assessment of the effectiveness and selectiveness of VespaCatch®, Jabeprode® and bottle traps for summer/autumn trapping

Véto-pharma
25 July 2021
Asian Hornets
8 minutes of reading

A recently published study conducted in 10 apiaries in the Eure department (Upper Normandy region of northern France) in the summer/autumn of 2019 compared the effectiveness and selectiveness of three Asian hornet (Vespa velutina) trapping devices commonly used by beekeepers. The VespaCatch® trap came out as most effective in the test (four times more effective than Jabeprode® and almost twice as effective as the bottle trap), with the same level of selectiveness as the bottle trap. The Jabeprode® trap proved to be the most selective, but with limited effectiveness.

Summary of the original article “Analyse comparée de l’attractivité et de la sélectivité de trois dispositifs de piégeage de Vespa velutina nigrithorax” [Comparative analysis of the attractiveness and selectiveness of three Vespa velutina nigrithorax trapping devices] published in the journal La Santé de l’Abeille No 303 (May/June 2020).

Study methodology

Each beekeeper installed three types of trap behind their hives, less than 5 metres away:

VespaCatch® trap + VespaCatch® attractant (Véto-pharma) [dilution: 10 ml of attractant + 50 g of sugar + 200 ml of water per trap]
1.5 L plastic bottle trap with a Tap-trap® cap + home-made bait (1 Pelforth beer + 1 tbsp of strawberry syrup + 1 tbsp of Picon® liqueur)
Jabeprode® device (wooden box equipped with Jabeprode® cones) + bait made with the wax from hive frames (melted in 1.5 L of hot water) + 20 g of honey, fermented for 3 days.

The traps were in place from 15/07/2019 to 04/11/2019.
The contents of the traps were counted every 2 weeks, and the bait was replaced for the bottle and VespaCatch® traps.

It should be noted that in 2019, hornet pressure in the Eure department was classified as moderate to low (1,319 nests including 560 secondary nests).

Results – Effectiveness

During the period of analysis, the VespaCatch® trap captured an average of 2.8 Asian hornets in the apiaries, compared to only 0.7 for the Jabeprode® trap, and 1.5 for the bottle traps.

There was a higher number of captures for three apiaries, indicating the probable presence of an Asian hornet nest nearby.

The attractiveness of the traps also seems to depend on the sampling period, with captures increasing in autumn.

Results – Selectiveness

The VespaCatch® trap was the most effective in catching Asian hornets, but it also trapped other species (including Diptera).
The Jabeprode® trap proved to be the most selective, but not very attractive to all insects, including the Asian hornet.
Finally, the bottle trap demonstrated a level of selectiveness identical to the VespaCatch® trap, but was much less effective (almost half as many Asian hornets captured).

Overall, 73,832 insects (mainly the orders of Diptera, then Hymenoptera and Lepidoptera) were captured, all traps combined.

Discussion

The authors hypothesise that the Asian hornets, which stay alive longer in the Jabeprode® trap, may have consumed some of the other trapped insects, artificially enhancing the results on selectiveness.
The location of the apiaries on which the traps are installed seems to influence their attractiveness. Traps appear to be more attractive in valleys, suggesting that these areas might be choice locations for Asian hornets.
The effectiveness of the different traps cannot be directly compared because different types of bait were used. To do so, it would have been necessary to compare the 3 traps using the same bait (but this would involve reviewing the total dose used, as the traps are of different sizes), or compare 3 attractants in a single type of trap.

Conclusion

The authors advise using only the most selective traps, and only when Vespa velutina pressure is high and colonies are under massive attack. They hope a more selective bait will be developed (pheromone-based in particular) in the years to come, or they hope to see a reorganisation of the food chain enabling natural control of the Asian hornet.

However, beekeepers will almost certainly not be able to limit themselves to this recommendation in reality. Hornet pressure is so high in some apiaries that they will have to opt for more attractive solutions (highly effective traps) in order to trap as many Asian hornets as possible and avoid the decimation of the hives.

A compromise between the two approaches is probably the most realistic option:

Only set traps in the trajectories of Asian hornets, especially near nests. If a trap is not catching any Asian hornets but it is catching many other insects: move it a little further away (sometimes just a few metres can make a difference), or remove it from the area.
The results of this study show that trapping effectiveness increases in later months (with significant numbers captured in autumn). Perhaps the choice of the trap, like the choice of the attractant, could be adapted as the season progresses.
Commercial traps do not all have the same price. From a €50 trap, to a €3 trap or a home-made trap; the budget for equipping an apiary can vary considerably. Tailor your trapping strategy to your budget. You can easily combine several trapping solutions to rationalise your investment.

Finally, here are a few tips that can help you optimise your trapping (recommendations from the VespaCatch® trap manual):

It takes a few hours for the traps to capture hornets.
It is recommended to set the traps when maximum day-time temperatures rise above 15°C.
For enhanced effectiveness, do not clean the trap when replacing the solution.
When replacing the attractant, it is advisable to leave a dead hornet in the trap.
Carefully follow the attractant dilution recommendations: 10 ml of VespaCatch® attractant + 50 g of sugar + 200 ml of water.

One thing is certain, selectiveness will be a growing topic of discussion in the debates on trapping Asian hornets. We can only hope to find a solution that could enable effective control of this invasive species while protecting the local entomofauna. We will continue working towards achieving greater selectiveness, without sacrificing effectiveness, in order to provide beekeepers with long-term relief.