Japanese Beetles - I read that they will eat wild geraniums and die. Haven’t had any real experience with trying that though.
Greeneyes: Finally, some normal weather!
Japanese Beetles:
“The beetle, Popillia japonica Newman, can feast on a wide variety of plants, including ornamentals, soybean, maize, fruits and vegetables. But within 30 minutes of consuming geranium petals, the beetle rolls over on its back, its legs and antennae slowly twitch, and it remains paralyzed for several hours. The beetles typically recover within 24 hours when paralyzed under laboratory conditions, but they often succumb to death under field conditions after predators spot and devour the beetles while they are helpless.” ...snip
https://extension.umn.edu/yard-and-garden-news/japanese-beetles-and-four-oclock-flowers
snip...”Later, geraniums and castor beans were tested, and only geranium had evidence of being directly toxic to Japanese beetles. Adding geraniums to protect the garden may seem like a good idea, but a University of Kentucky study found that planting garden geranium (Pelargonium × hortorum) actually increased Japanese beetle damage to nearby roses. The reasons why are not clear, but the scientists suggested that geraniums may have attracted more beetles in the area due to their flowers’ scent or color.
A recent Colgate University study in 2013 seems to put another hole in the “four o’clock is toxic to beetles” theory. In this experiment, a four o’clock leaf was put in a cage with a starving Japanese beetle. While the scientists did find that some varieties of four o’clock were tastier to the beetles than others, no dead or sick insects were observed in any cage.”
My observations: One year I planted Germaniums in pots. Although not more than 40 feet from the heaviest infestation area I do not think they recived a visit as far as I could tell.
I read that J.Bs and do not like Red Cedar oil, so I sprayed my Plum trees and Aronia with a mixture of Sal suds soap, neem and Red Cedar oil. They pretty much left the older sprayed leaves alone and concentrated on the new leaves on the tips. So, it does reduce the visits.
(Note** First year of infestation I used a Japanese beetle trap, which I will never do again. It attracts a massive amount of them. I have made 2 applications of Milky Spore and at least 1 of predatory nematodes in the past 3 years with a reduction of population. I am waiting for the first visit this year.)
https://verminkill.com/plants-that-repel-beetles/