Japanese Beetle - Popillia japonica
Today's post will be a short one regarding an observation for this prominent specie of metallic Scarab. When the sunlight returns, these individuals do at it again: nibbling on plants while keeping to the shade, eventually forming small groups while keeping out of Toronto's summer sun. It's typical behaviors of these full-grown adult Beetles, and they must eat in order to keep up their strength. As far as their adult diet goes, they've been shown in earlier posts here to be generalist feeders that aren't fickle on which plants they eat. They will also subsist on many different parts of a plant, depending on what's available between leaves, flowers or other important structures (meanwhile the larvae dwelling underground will gnaw away at roots). What surprises me in these images is the seemingly indiscriminate manner in which these individuals consume these leaves. It's a patchwork of literal scenery chewing which leaves only the veins mostly intact! However, looking at what's left behind as a result of these individuals' feeding brings about a tantalizing question: are the Beetles in the Odd-Numbered pictures intentionally leaving behind plant material in between the leaf's veins to maintain structural integrity and a surface to climb on?
I think they might be! If they were to consume the connections between the leaf they could conceivably lose potential food, shelter and a suitable mingling location. Although on the smaller side of the Scarab family, this specie is still hefty, and requires a firm grip to avoid tumbling to the ground. Especially since they posture by displaying the spurs on their hindlegs. Keeping this brief observation in mind, I will more carefully observe this specie (and other potential Leaf-eating Beetle finds) to see how this behavior changes or adjusts depending on the plant chosen for food. I'd like to comment on the Even-Numbered individual on the goldenrod leaf, but they were not made by that Beetle. That individual was one that took a tumble (in defense) from my approach and was re-placed upon that leaf, as my hand was at the ready. To close, experience has taught me that a good few insects are droppers who will fall into the soil below a plant for safety, and as such, a well-placed hand will allow you the chance to catch the insect and observe it further, That said, only attempt this on insects which are positively identified as safe, and be as gentle as you can with them.
Pictures were taken on July 6, 2025 in High Park with a Google Pixel 8a. May the green colors on display here help bring you into the holiday spirit!