Fortunately wasps are pretty easy to google, especially ones with distinctive marking. Google led me to a local catalog of wasps which yielded a scientific name to plug back into google. Wikipedia revealed that the female wasps of the species burrow in search of Japanese Beetle grubs. Finally! A predator of japanese beetles attracted to my farm! And more importantly, its native!
The japanese beetles decimated my young grape plants by eating most every leaf in the week I was gone for a wedding. So I set out to find a biological solution to combat these pests.
Chickens and other fowl will eat the larvae from the ground decimating the adult population of beetles preemptively. But this is not much help in my current situation!
Another common solution is good old fashioned hand removal of beetles into a bucket of soapy water. If you have chickens, just drop the beetles into the bucket of water and use them as treats for the chickens once the beetles drown. This has been my course of action.
Beetle traps are not recommended because they attract more beetles from far away leaving the gardener to deal with the beetles widely surrounding the garden instead of only those in close proximity of the garden itself. Plus some research has shown that beetles deploy pheromones to attract others when an individual finds a food source. Certainly not ideal!
Yet I was surprised not to find any documented plants that trap or at least attract japanese beetles away from the harvestable crops. Again, simple observation has proven its power.
This plant has drawn all the beetles in the garden to it. Clearly they are heavily feeding on the leaves and clearly they are making the next generation of beetles atop this plant. Instead of many many beetles on the remaining 10% of my grapes leaves (decimate is to be taken literally both times in this post), there is usually one every few days. This plant is drawing them away from the valuable crops allowing me to focus my soapy water removal strategy on the two places where this plant grows opposed to every grape and hop plant in the garden.
I’ve been trying the key this plant and figured out the genus: Persicaria. I will have to wait until it flowers and maybe fruits to find the genus. Needless to say, this plant will be in my garden every year!