Repellents versus "-cides"

I had planned to mulch yesterday in the two beds that still lack mulch since the forecast is for five more days of 90 degree temperatures with dew points in the 70s. Weather like this means stress for some plants – especially transplants – and mulch can help. It cools the soil and holds in the moisture. But, when sweat was pouring off us as we took the dogs for a walk, I decided to change my plans and stay indoors—in the basement, actually since the fans weren’t keeping us very cool.

The day I was experimenting with essential oils for insect repellent, a neighbor asked me if it would work on getting rid of the Japanese Beetles in her yard. We then had a good conversation about the difference between repellents (compounds designed to keep the bugs away from you) and “-cides” (compounds designed to kill that which precedes the –cide).

I’m battling the Japanese Beetles, too, but am loathe to use an insecticide, because many of them are broad spectrum killers and I want to keep the butterflies and the bees – so I’ve been going out a couple times a day and picking the beetles off the plants (roses mostly) and dropping them into a container of soapy water. (The soap coats their wings so they can’t fly away.) I know it sounds cruel, but they’re eating my roses!

I haven’t done a lot of research on natural or specific insecticides, but there’s a week of 90s ahead – providing lots of opportunity for research. If you’ve found a natural insecticide that doesn’t harm bees or butterflies, post a comment and let me know!