Bird predators and distraction plants for Japanese Beetles - my two discoveries from summer of 2020.
Hello everyone! I am new and here is my first contribution :-)
I have previously read that
native birds were not interested in Japanese beetles, which was a disappointment. HOWEVER! This summer, to my big surprise, I personally witnessed a male Cardinal gobbling them up from a branch on a young tree in my backyard (an elm, I believe). I am not sure if that was an "opportunistic lunch", or if Cardinals actively seek them out, but who cares, at least there is a creature in the natural world that will eat them! I talked to my
gardening neighbors and confirmed that they too saw Cardinals feeding on Japanese beetles. One of them said she kept a feeder in the middle of her
rose shrubs stocked even in the summer, and once the birds were there, they took care of the bugs to her satisfaction. It
should be noted that Cardinals are not very "acrobatic" as compared to, say, chickadees or nuthatches, so a feeder with a flat feeding surface is needed to make sure they are able to hang out at the feeder for some time. Has anyone seen any other birds feed on Japanese beetles?
In addition, last spring I happened to plant a few native flowers around my rose shrubs, and one of them seemed to act as a "sacrifice/distraction/trap" crop, in that if the year before all of the Japanese beetles were piled up in rose flowers, this year there were hardly any on the roses growing next to this flower. Instead, the beetles were mostly on this flower plant, which is a White Gaura (see photo). I am planning on planting more of all kinds of Gauras! It proved to be a very happy-go-lucky plant. The base crown forms a roundish ball of attractive blue/green foliage and stays evergreen in my Zone 7 climate (the bunnies did a number of it this winter though; but they did not bother it in the summer). It flowered profusely from early spring to mid/late summer, and was teaming with all kinds of small-ish
bees and other insects feeding on nectar. The flowers are long stemmed, small, flat and white, so the beetles are very visible on them and it was very easy to grab a cup with some soapy
water and shake the beetles off into it with precision difficult to achieve with rosebuds and flowers as beetles bury themselves in all those petals. With all these beetles hanging out on the Gaura, the plant itself did not seem to incur any damage or show any stress; it never slowed down flowering and there were no signs of chewing on stems or leaves..
From what I could observe, another rose shrub within 10-15 feet of Gaura planting also benefited and was mostly beetle-free. However, roses planted in the backyard (about 50+ feet away) lost the protection - there were loads of beetles on them.